Coolant Loss, Power Loss

[JayPinNC]

Took my wife, son and two of my wife's co-workers to a Christmas party this weekend - and to say my XC was gutless would be putting it lightly. At first, I thought maybe it had something to do with the two extra adults in the car, but they only added maybe another 300lbs. I inflated the tires a little more to compensate for the added weight (to the 39lbs the gas tank door suggests).

But I know these two things probably had no effect on how the car ran. I had to give it far too much gas to get it moving. Once it got up to speed, the power was ok, but I think that's the whole 'objects in motion...' thing. My mileage has been getting progressively worse, and I see 275 miles to empty on a full tank, whereas I was getting465+ miles to empty 6 months ago.

So Sunday, while I was deflating the tires back to the normal pressure, I looked under the hood and noticed my coolant reservoir was a little low. I haven't had to top it up since I put the new reservoir and sensor on a few months back. It had dipped down about an inch to just above the MIN mark. I also noticed some condensation on my oil dipstick and the oil level was a tiny bit higher than normal - but I usually don't check the car when it's cold - I wait 5 min after running, so it could be my imagination and more oil pooling in the oil pan.

But when you take the loss of power, poor MPG and disappearing coolant, I automatically think the worst.

I mean, it could be multiple things that have nothing to do with each other? Right? I'm taking it in for a diagnosis on Wednesday. The shop says they don't charge a diagnostic fee if it turns out to be the head gasket - they feel so sorry for you that they waive it regardless of whether you get the car fixed or ditch it.

Anybody got something better than 'head gasket' to help me sleep tonight?

[Astro14]

OK - so you've seen 3 things: condensation/oil level, coolant loss, and power loss. But seeing all 3 things at once doesn't mean they are related...they could be related (head gasket is first thing that came to my mind).

However, you've noticed a progressive loss in power over 6 months...but it hasn't been sucking down coolant for the same time, has it?

The condensation on the dipstick and change in level may be due to head gasket...or the fact that you checked it cold and you've never done that before, so you can't really compare that level or appearance with previous results.

It is possible that you've got 3 unrelated problems - 1. the oil level check is a red herring, 2. you've got a small coolant leak that you've not found and 3. you've got another problem causing poor performance.

Given the range of possibilities - it's worth getting it diagnosed. You may have blown a head gasket, but I am not convinced that is the case until you've got more data points.

Good luck

[kamiar]

The coolant being low a little bit, specially if you have changed the reservoir and sensor only a month ago is normal i think....

The mileage suffers badly with colder weather...

And didn't you happen to press the "W" switch accidentally?

[JayPinNC]

Well, the reservoir was a few months ago later summer-ish- but I read a post recently where someone had low coolant and it turned out to be the thermostat - sticking open if I recall.

As for the cold weather - sure, I can appreciate that, but the power loss was very noticeable, and I've driven the car in similar weather recently.

As for your question about the W switch. If I pressed it, the light didn't come on. The button itself has stuck since I got the car. I think the previous owner spilled something in it. Does "W" mode shut off when the car is shut off?

[Forkster]

Well, the reservoir was a few months ago later summer-ish- but I read a post recently where someone had low coolant and it turned out to be the thermostat - sticking open if I recall.

As for the cold weather - sure, I can appreciate that, but the power loss was very noticeable, and I've driven the car in similar weather recently.

As for your question about the W switch. If I pressed it, the light didn't come on. The button itself has stuck since I got the car. I think the previous owner spilled something in it. Does "W" mode shut off when the car is shut off?
Depends - is it stuck 'on'?

[JayPinNC]

Depends - is it stuck 'on'?

I should clarify - if I press the W button, it gets stuck in the console and the light turns on. Usually with a few light taps and some massaging, it pops back out. Is it possible to be out enough for the light to be on, yet still be in W mode?

And that's where my question about turning the car off came into play - I was wondering if turning the car off canceled W mode. The button (on my car at least) isn't the kind that clicks into place so you know it's on - the light is the only indication)

I also counted the shifts - I was starting in 1st gear unless I was counting wrong. :-)

[Seamus]

We have had a coolant leak out of the blue recently. But I do think it's thermostat related as the car never warms up, but I'll know when it comes on Thursday. But its not a large leak at all, it's just a wet spot under the bumper to the right.

As for the loss of power, how was the temp of your engine? I know when I start off cold the car feels extremely sluggish for the first mile or 2, and same goes for highway driving in the cold, since the thermostat is busted it cools right down and feels sluggish at slow speeds.

If you think your car is in winter mode even if it shows no indication, slip it over to geartronic and if is says 3, then it's in w.

Hope this helps,
Seamus

[JayPinNC]

Thanks Seamus - it does help. I'll flip into geartronic when I take a spin around the neighborhood tomorrow.

The temp seemed ok, it's been running a little to the cool side of halfway from time-to-time. With your own thermostat busted - what does your temp gauge read?

[Seamus]

Well it depends on the speed and the outside temp. If it idles or drives slowly it almost gets to normal temp, but doesn't stay long. Even when I hit around 30 for say 10 mins it drops waay down to like 3 or 4 notches above minimum. Lol, and on the highway? It just drops all the way down. If the thermostat is your problem, be happy, because it's a 13$ part and a whole lot easier to replace in our 01's lol.

Good luck,
Seamus

[sjonnie]

Took my wife, son and two of my wife's co-workers to a Christmas party this weekend - and to say my XC was gutless would be putting it lightly. At first, I thought maybe it had something to do with the two extra adults in the car, but they only added maybe another 300lbs.

400lbs+ surely, unless they are all stick insect thin. That's a considerable load, definitely enough to make you notice you need more throttle if you're sensitive to that kind of thing. Still, if you punch it, it should go, 200 horses are enough to pull even the heaviest of administrative assistants :)


Once it got up to speed, the power was ok, but I think that's the whole 'objects in motion...' thing. My mileage has been getting progressively worse, and I see 275 miles to empty on a full tank, whereas I was getting 465+ miles to empty 6 months ago.

Maybe the cumulative effect of winter gas and city driving. When did you last change your oil? It's been cold down that way, if you're running a 10W30 or something your mileage will be suffering. Plus we tend to make shorter, round town trips in the winter = poor mileage.


It had dipped down about an inch to just above the MIN mark. I also noticed some condensation on my oil dipstick and the oil level was a tiny bit higher than normal - but I usually don't check the car when it's cold - I wait 5 min after running, so it could be my imagination and more oil pooling in the oil pan.

Five minutes is nowhere near enough time to drive the water out, you need 20-30mins of full temp running to do that. That's why cars suffer badly from short winter trips, the condensation never gets driven out of the oil. Cold oil should actually read lower on the dipstick, hot oil reads about 10% higher due to thermal expansion of the liquid.

If you suspect head gasket you need to sniff some exhaust fumes, the sweet smell is pretty distinctive. Just put your face near the exhaust and waft the fumes in your direction with your hand, if you smell the glycol you'll be able to tell immediately. If you smell nothing just top the coolant up and monitor the level over the next few weeks. Maybe do an oil change to 0W30 now while you're busy with the car.

[JayPinNC]

Ok, maybe it was closer to 400lbs...plus a 6 year old in the 3rd seat.

Last oil change + filter was about 400 miles ago - 5W-30 synthetic (Shell brand - I ran out of Mobil 1) I hadn't really thought about winter gas, but it could be part of the equation.

As for my mention of checking the oil - I check it 5 minutes after a trip of at least 10 miles. I could have worded that better. 5 minutes seems long enough for most of the oil to drain down into the pan.

I don't have any oil in the coolant that I can see.

[JayPinNC]

If the thermostat is your problem, be happy, because it's a 13$ part and a whole lot easier to replace in our 01's lol.

I hear ya. And it's also one thing I have not yet done. Probably something to try. I did change the coolant over the summer though.

[Seamus]

It couldn't hurt. But I have one question, when they replace a water pump with a timing belt, do they have to drain all of the coolant? Cause they charged 33$ for new coolant and I'm wondering if that counts as a flush or not

Seamus

[JayPinNC]

It couldn't hurt. But I have one question, when they replace a water pump with a timing belt, do they have to drain all of the coolant? Cause they charged 33$ for new coolant and I'm wondering if that counts as a flush or not

Seamus

It probably counts as a 'replace.'

[Seamus]

It probably counts as a 'replace.'

Ahh, well I the low coolant message hasnt popped up since then, even though I find it unlikely the water pump was leaking. But it may be something to look into if all else fails.

[JayPinNC]

I just started it up to see how it felt idling. I got some white smoke at startup, but that's pretty normal on every car I've had (plus it's 35-40 degrees outside right now). The white smoke subsided when the car got hot. My sense of smell isn't so good. Can't tell if it smells like coolant or not.

Also, after the engine was about 1/2 way warmed up (temp needle at about 10:30 position), I took the oil filler cap off - there was some white-ish stuff (condensation?) on it and the dipstick didn't seem to have the milkshake-y film I noticed yesterday.

Oh and as the car warmed up, I noticed the coolant reservoir filling up slightly. Not sure if that has any significance. I'm still taking it to a shop tomorrow to get a diagnosis.

[Huzer21]

Sounds thermostat-like to me. Ridiculously easy to swap out (2 torx bolts). Is your car reaching normal operating temp when driving? (highway?)

[JayPinNC]

It's been normal (12:00 position) most of the time, but I have noticed it lower than that a few times as of late. Maybe 1 or two lines to the cool side.

Can power loss come from a bad thermostat? I don't think I've ever had one go bad, so I'm just curious.

[Seamus]

It's been normal (12:00 position) most of the time, but I have noticed it lower than that a few times as of late. Maybe 1 or two lines to the cool side.

Can power loss come from a bad thermostat? I don't think I've ever had one go bad, so I'm just curious.


Don't think so. Ours was bad for quite a while and power seems normal. Except when totally cold

[Huzer21]

It's been normal (12:00 position) most of the time, but I have noticed it lower than that a few times as of late. Maybe 1 or two lines to the cool side.

Can power loss come from a bad thermostat? I don't think I've ever had one go bad, so I'm just curious.

Power loss I did not have from the thermostat. I apparently misread earlier posts as I thought that was attributed to the extra weight in the vehicle. I would say as far as variations in my temp gauge, since I've replaced the thermostat on my car, it's been rock steady at 12 with no deviation once the car is warmed up.

[Astro14]

Let us know what the shop says - to drive the condensation off from the crankcase/oil takes a good highway run at operating temp - say 30 minutes. so, just warmed up - a bit of condensation under the cap is not significant.

A malfunctioning thermostat won't cause the engine to lose power unless it's very cold. Even slightly cold (cold enough to go open loop, where the O2 sensor input is ignored) usually results in NORMAL power...but higher fuel consumption as the engine runs a bit richer than in closed loop.

"White smoke" - that's worrisome...normal condensation...or real smoke? The latter is clearly a head gasket.

Coolant level rising slightly when warm is normal - means the sytem is full and working...

Shop should do a pressure test on the cooling system - will help track down any leaks. Other data points: emissions tester to "sniff" coolant...to see if exhaust gas present in coolant (Head Gasket).

As discussed previously...you may have 3 unrelated, but concurrent issues...

Good luck!

[JayPinNC]

Pressure test on the cooling system didn't show anything abnormal. I have to go back and pick it up tomorrow to find out exactly what they did.

however, after driving to the shop at between 45-55mph for about 45 min, the suspect liquid in the crankcase seemed to be gone - no milkshake. Just golden oil since I change it about 500 miles ago. I'm thinking that part of the equation was indeed condensation forming on the coolest parts of the crankcase (filler cap and dipstick). Maybe I just assumed the worst having an 01? Who knows...

As for losing coolant, this thread could explain it: http://www.volvoxc.com/forums/showthread.php?p=121255 - not sure. I'm pretty sure I have the original thermostat though.

The white smoke is only at startup. Once the engine is fully warm, the exhaust stops being white.

The last thing I'll point out is that I'm hyper-sensitive to anything that happens in the car. So maybe I was just too in-tune to the performance I got at that temperature with two extra adults in the car.

Anyway I'll know more tomorrow. I'll let you know. But as of right now it looks better than it did yesterday. Thanks for all your input - feel free to keep adding to the thread.

[Seamus]

I was just thinking about why could make your car lose power. And if you say that you are hyper sensitive to the way the car behaves, I think this might be it. I noticed the same thing when we picked up my brother from college. With all the stuff and the 3 of us, the car felt significantly slower. It sounded normal and everything, but was sluggish off the line. I noticed this because I think I may be sensitive to the car as well. It's interesting though how weight would effect it so much, cause when its empty, it seems to have all the power in the world when it's empty

[JayPinNC]

Ok, the shop found no indication of any head gasket leak. They said there was definitely condensation in there though that made the oil look contaminated.

So it could be three separate things going on after all: Thermostat (it's still running 1 tick to the cools side, moisture (I don't do a lot of long drives) and some sort of intermittent power issue - which I didn't notice today.

That and the fact that I'm hypersensitive to every little thing about this car. But I guess it's better to err on the side of caution...

[Aviator]

Jay, you worry about things too much.:)

Dave.

[Aviator]

to drive the condensation off from the crankcase/oil takes a good highway run at operating temp - say 30 minutes.

Negative. That condensation gets mixed/suspended in with the oil and circulated around the engine until the engine stops afterwhich the condensation falls out of suspension and back to rest beneath the oil again. It takes and engine overhaul to completely eliminate the moisture. The only thing that might work is 1/2 L or so of Varsol or kerosene in with the oil and drive the feck out of it for an hour or so then immediately change the oil.

Dave.

[JayPinNC]

Jay, you worry about things too much.:)

:) Probably.

[PierreC]

Hi

The power loss could be attributed to the Turbo Control Valve (TCV) ... happened to me some time ago. Not expensive and easy to replace yourself, or, if you want to get a "performance boost" in the form of much more responsiveness from the engine, go for the IPD Heavy Duty TCV ... and eplace the hoses as they recommend!

Kind regards
Pierre

PS And a very joyuous and peaceful Christmas to all VolvoXC forum readers!

[JayPinNC]

Thanks Pierre. I've actually got a complete DIY HD TCV that I just finished (had to borrow a soldering iron to get it done) - I'll get it installed in the coming days and let you know.

I hope you, and everyone else on the forum, has a great Christmas, too!

[kamiar]

Hi

The power loss could be attributed to the Turbo Control Valve (TCV) ... happened to me some time ago. Not expensive and easy to replace yourself, or, if you want to get a "performance boost" in the form of much more responsiveness from the engine, go for the IPD Heavy Duty TCV ... and eplace the hoses as they recommend!

Kind regards
Pierre

PS And a very joyuous and peaceful Christmas to all VolvoXC forum readers!

Did you have any trouble codes etc as a result of bad TCV?

[JayPinNC]

If you're asking me, I did not. But I'm still putting on a new one.

[kamiar]

If you're asking me, I did not. But I'm still putting on a new one.

Please let me know if it makes any difference....

[Astro14]

It’s important to define terms so we’re talking about the same things; condensation and sludge for example are related, but very different things.

Condensation is moisture that precipitates out of the air inside the engine. All air has water vapor in it, the amount of water vapor that the air can hold is a function of temperature.

If warm, moist air is cooled, the vapor condenses out and appears as water in its liquid form. This is where morning dew on the grass comes from…same thing can happen in an engine’s crankcase when it cools.

Any fluid, water included, will maintain an equilibrium of liquid and gas in an enclosed space…like the crankcase. The pressure of the vapor over the liquid is determined by the temperature of the system, and it's a constant at a constant temperature. So, raise the temperature, and the equilibrium vapor pressure rises. The equilibrium vapor pressure is an indication of a liquid's evaporation rate. It relates to the tendency of particles to escape from the liquid (or a solid). A substance with a high vapor pressure at normal temperatures is often referred to as volatile (e.g acetone or gasoline). The water doesn’t have to be boiling to vaporize. Look how much quicker water evaporates on a hot vs. cold day.

Driving the car raises the temperature in the crankcase and you get an increase in the crankcase air’s ability to absorb water as well as an increase in the equilibrium vapor pressure of the water.

If the air in the crankcase is then exchanged (via the PCV) with drier air, then the liquid water in the crankcase will evaporate to maintain that equilibrium vapor pressure, continued operation at the higher temperature will continue the process with more water evaporating into the fresh air until all the water is gone from the crankcase.

If the engine never really warms up, then the system can’t extract the vapor, the water is happy being cool, with a low vapor pressure and it remains inside the crankcase. If it mixes with oil, you get that creamy stuff on the underside of the oil cap, for example.

Now, if a head gasket is leaking, you get ethylene glycol in the oil as well – same appearance, very different stuff…the equilibrium vapor pressure of glycol will never get high enough to drive it off, and you've got to fix the leak as the glycol degrades the oil's ability to lubricate the engine.

But for simple condensation, a good long run at operating temperature will evaporate all of the condensate – Jay, the disappearance of the milky foam in your engine after a 45 minute drive to the dealer demonstrates the removal of the condensate. I don't think you've got a HG leak, or it would not have cleared up after the drive to the dealer.

Sludge is another thing altogether.

Sludge is generally black in color, a solid material with low water content, of dark color, light oil insolubles, and it is typically found in rocker cover, cylinder head, timing chain cover, oil sump, oil pump screen, and oil rings in variable quantities.

The cause of Black Sludge is a chemical reaction between the oil and combustion byproducts that get past the rings, including water and oxides of nitrogen (that together form nitric acid). The additive package in modern oils is designed to fight the formation of sludge through the inclusion of alkalines that combat the acids and therefore, the formation of sludge. In oil engineering, this alkalinity is called TBN (Total Base Number) and when the TBN drops below about 1.0, the oil additives are worn out and sludge will begin to form as the acids overpower the alkalines. New oil starts with a TBN between 8 and 5, depending on brand/product.

The longer oil is run, the lower the TBN will drop. Higher oil temperatures, low oil quantity and poor PCV also accelerate drop in TBN as the additives are used up more quickly.

If you’ve run your oil too long, or your driving is mostly short trips (so the condensate is never completely removed) you will form sludge in the engine when the additives are worn out. That’s why “severe service” calls for more frequent oil changes – to keep the additive package (and the TBN in them) fresh.

Once sludge is in the engine, getting it out must be done carefully.

Running the engine with a mix of motor oil and an aromatic solvent, like kerosene, used to be the trick to clean the engine. My 1932 Packard manual calls for doing just that. But the thinning of the oil by the solvent will most likely cause engine bearing damage in a modern engine like your Volvo. Even in the Packard, which was a pretty low stress engine (6.0 to 1 compression, 5.2 Liters, 110HP…), it was recommended to just idle the engine with the thinned oil. I wouldn’t dare drive the car with thinned oil…

The other risk with an aggressive solvent is that it will break free enough sludge to plug the oil pump pick-up screen or some of the oil galleries, starving the engine of oil and causing bearing or component damage.

If you think you’ve got sludge, then any good quality oil will begin to attack/dissolve it with the additives already built in. Some other options include Auto RX (not a solvent, a detergent) and Seafoam (less aggressive solvent) but frankly, you’re better off to try and remove any sludge slowly through the action of the oil detergents alone. The soft sludge will dissolve pretty quickly (and turn your oil black) but the hard black, crusty kind is not going to be easy to get out…and an engine rebuild is the best way to get rid of it…

In all honesty Jay, if you’ve been good about changing your oil, I doubt you’ve got any sludge in the engine, but you should consider running the car for 30 minutes on the highway once a week in the winter to keep the condensation down, or cut your oil change interval in half to keep the TBN high and preclude sludge formation.

Cheers,
[thumbup]

[JayPinNC]

I can't speak for the previous owner, but it looks like they had the dealership do most of their repairs, so I'm guessing that they did oil changes too.

Now, with what kind of oil I can only speculate. But since I've had the car, I've only done synthetic and Seafoam with every change. I've got some varnish built up - you can see it here (http://picasaweb.google.com/lh/photo/P8Z0EPAmebN-VToFWOn06A?feat=directlink). But since that pic was taken, I think it's gone down some - could be the seafoam/synthetic combo.

I do usually only take short trips with the car, but I do try to get out on the highway (70mph, straightaway) and let it get up to speed when I can.

The night before I noticed the milky gunk on my dipstick was very wet - the trip to the shop (even though I never got over 50 mph) did seem to remedy it.

As for sludge, I've been doing 3,000 mile changes (and the Seafoam as I mentioned) so I can only hope that it's helping remedy as much sludge as possible - assuming there is some. The PCV was done past when I think it was due, however I did get it done soon after buying the car.

Thanks for your input - I had no idea what a TBN was before now.

[Astro14]

With the short Oil Change Interval (OCI) and the good oil - you should be fine, even with mostly short trips. I think you're doing about all you can do for the engine...3K is a very short interval for synthetic...

The fact that the 45 minute run to the dealer cleared up the gunk tells me it's simple condensation, to be expected given the short trips and the damp weather beforehand. It isn't so much the speed at which the car is run as it is time spent at operating temperature - that's what drives off condensation.

It's hard to judge from a picture...Looks like there is a bit of hard build-up in there, but I wouldn't sweat it. By following a good oil change interval, you're keeping the the engine as clean as you can...if any of the bearing surfaces were damaged, you would know by now...I had an Oldsmobile (350 Rocket V8) that looked much like that under the valve covers - a bit of carbon build up. Ran it that way with 3K oil changes (regular oil, nothing fancy) until it had 220K on the original motor...and sold it, still running perfectly, because the Navy was sending me somewhere I couldn't take it...

There are a number of BMW owners who have destroyed their engines by agressively treating sludge build-up. They ran the car past the 15K/one year OCI (...BMW requires very specific oil to make it that long) and when they saw all the sludge they had built up from neglect, they tried to clean it out quickly...and plugged up the oil pickup and starved the engine of oil...surf the BMW forums...half of what those guys talk about is sludge...and no wonder, with a 15K OCI...

If the car is running OK, then don't worry about it...taking drastic steps is more likely to cause harm than good...

Cheers,

[PierreC]

If you're asking me, I did not. But I'm still putting on a new one.

Hi JayPinNC and kamiar

I have been "offline" for a while enjoying my summer holiday :) here in the southern hemisphere ... for those in the know, Jeffreys Bay where I have a beach cottage and then the (in)famous Route 62 here in South Africa, which is modelled on the US Route 66 ...

Kamiar: The first TCV "failure" on my car occurred early in its life (20.000 miles) and it was replaced under warranty. Like JayPinNC, I recently decided to replace the TCV (in my case, with a IPD heavy duty unit) after I did an Evolve performance tune, and in order to improve responsiveness ... it worked!

JayPinNC: Have your replaced your TCV yet? Any improvement? Did it solve your power loss problem?

Kind regards
Pierre

[Forkster]

JayPinNC: Have your replaced your TCV yet? Any improvement? Did it solve your power loss problem?

Kind regards
PierreI was going to ask the same thing. Did it work? :)

[Seamus]

Did you ever find out why the coolant was leaking? Our coolant which was leaking consistently for two months has totally stopped (knock on wood). I have no idea why, but I'm not complaining lol. Very interested though

Seamus

[JayPinNC]

I'm waiting for a warmer weekend and a chunk of time time to replace + test the TCV, but I'll give you all a full report. Heck, maybe a video. Been busy with work - and I work from home so you know I'm busy when I can't take 30 min to swap out a TCV and go for a drive.

As for the coolant - no clue. No evidence of a leak, but my temp gauge still shows a little to the cool side. I don't seem to be losing any more coolant from the reservoir. For the price of a new thermostat and how easy it is to do, I'm going to replace it.

Right now the power loss is intermittent. For example, today I drove my son to school - back roads, 45mph max (11 miles round trip). On the way back, the car felt like it was lacking power. I stopped at a stop light, made a legal and safe right on read and the power seemed to magically re-appear. 1000 yards later, I slow down to make left (no stopping) and then accelerate and the power is lacking again.

Anyhoo, I'll report back when the TCV is swapped out.

[PierreC]

Did you ever find out why the coolant was leaking? Our coolant which was leaking consistently for two months has totally stopped (knock on wood). I have no idea why, but I'm not complaining lol. Very interested though

Seamus

I had a spurious incident of coolant loss on my S60 a while ago ... tightened the coolant expansion tank cap and it disappeared! ... hopefully permanently

[Seamus]

Jay,

I had the thermostat replaced today, and with the car operating at full temp, it seemed to have more power and run mug smoother. Even when it was just below full temp, it didn't seem right. The thermostat was broken in half btw :eek:

[JayPinNC]

Jay,

I had the thermostat replaced today, and with the car operating at full temp, it seemed to have more power and run mug smoother. Even when it was just below full temp, it didn't seem right. The thermostat was broken in half btw :eek:

Was it the original thermostat?

[Seamus]

I'm pretty sure. We havnt replaced it since we got it, and that was at pretty low miles. So probably not. I was amazed at how fast the car warmed up.

[Chilled Man]

It's been normal (12:00 position) most of the time, but I have noticed it lower than that a few times as of late. Maybe 1 or two lines to the cool side.

Can power loss come from a bad thermostat? I don't think I've ever had one go bad, so I'm just curious.

Power loss will come from a bad ECT Sensor.

I will put the car into limp mode and the shifting will be funny and you will have a major loss of power.

I would change the thermostat , ect sensor and drain and fill the coolant .

Also to check if your head gasket is bad turn the expansion tank on its side and if you see bubbles your screwed.