Oil Leak

[gridgewell]

I resently pulled the oil pan and fixed the oil leak that was coming from the front of the engine. That came out great. Now I have another leak coming from the same areea, but not from the pan. I pulled the timing cover and it does not look like the front seal. Does the XC70 have a history of head gasket leakage from this area? This would seem to be a lot of work to fix. Is there anthing else I should look for that may be the problem?

[Astro14]

There are only a few places that the engine can leak: Front main seal, rear main seal, cam seals, oil cooler, turbo lines, oil fill cap...you get the idea...the head gasket is uncommon but possible.

So, on the front (passenger side in the US) of the engine, I would be looking at the cam seals if the leak is above the Front Main...

But any time there is a leak in this engine, I have to ask "why"...and the most common answer is not that the seal itself is bad, but that crankcase pressure is building from a plugged flame trap (the PCV system).

Check the flame trap first, clean the nipple by the manifold, replace the whole system if it's sludged up...then clean the engine thoroughly and see how the leak looks...

[gridgewell]

I replaced the flame trap (the PCV system) last night. Boy was it clogged. The port going into the engine behind the trap was full of sludge. Lot of work taking the intake off...Well at least for a first timer. Engine runs a lot better. I cleaned the engine up and will let you know if the cam seal stops leaking. If not is that a tough job to change? thanks for all your help!

[Astro14]

I am always pleased when things work out...I'll bet your oil leak subsides...

I haven't changed a cam seal, but the T-belt would have to come off...and that's a few hours (you'll need to buy, rent or make a crankshaft pulley holder for the job). Once it's off, removing the gear and replacing the seal shouldn't be too much more...

My personal recommendation at this point is to shorten your oil change interval to 3-4K and use a good conventional or stick with the factory 7500 mile/1 year and go synthetic....see my oil rant...and ignore the old wives tale that you can't use synthetic in older engines, or that you can't change back and forth from synthetic to conventional...completely untrue...

Sludge forms when the oil begins to become acidic due to contamination from combustion byproducts. Conventional oil is more susceptible to boil-off of the more volatile components...both instances will put more gunk through the PCV system...

[gridgewell]

Looks like the oil leak has stopped! It took about two weeks to get all the oil out. Thanks again

[rgaspar]

hello,

I am new owner of a 01 xc w/ 112k mi.
there is oil leaking near the front drivers side. i noticed your post but maybe missed the start of it ? you mentioned a fix around the pan and then the flame trap. could you elaborate on either of these? I want to see what diy work is possible before going to a mechanic. i just paid $1k for a new brake booster & tie rods.

thanks,

[Astro14]

Flame trap is a box on the front of the engine that is part of the PCV system...oil vapors travel from there to be burned in the intake manifold and that keeps pressure from building in the crankcase.

The system is notorious for getting plugged up with sludge. When that happens, the pressure in the crankcase finds another way out: via one or more oil seals...and some oil goes with it...

So, question for you is: exactly where is this leak? And has your PCV been checked?

If you, or the Previous Owner, used conventional 5W30 and then drove the car on lots of short trips or in cold weather during the 7500 mile oil change interval, you likely have sludge in the PCV system that is causing this leak.

There is more to oil than the viscosity. Some oil is chemically engineered to handle long drain intervals, some is not...and 7500 miles during really cold weather operation, or lots of short trips, is a long drain interval...

[rgaspar]

Car was purchased at a 'used car lot' without any service documents so..... is there a link to a diagram of the PCV? Is this something I can check visually by getting underneath the car or does it require the removal / disassembly of some parts? thanks for the quick reply

[JRL]

Yes, it's a biggie
Intake manifold has to be removed
2-3 hours for a trained VOLVO mechanic, sometimes a full weekend for the backyard mechanic!
It's tricky
There are shortcuts but not for someone who doesn't know or understands the system

[chik]

Just to throw my two cents in...I've had three oil leaks serviced on separate occasions. First one was minor, second and third were major leaks.

#1- was probably before I hit the 100k mi. mark and had to do with the turbo return lines. IIRC, the oil leak for this was on driver's side.

#2- at 108k mi. intake camshaft seal. occurred while driving and oil went all along undercarriage and big puddle at parking lot after stopping. A mess!

#3- 123k mi. dealer found leak at CVVT seal and turbo return lines. Had them replace flame trap and PCV hoses, cleaned out whole PCV system.

No more oil leaks to date at 131k mi. Should have done flame trap/PCV system before leak #2. Might have saved some time and money. Agree with Astro14 wholeheartedly, keep that crankcase pressure from building up by maintaining/servicing oil and PCV system.

[anyadang]

I just recently purchased a 2003 XC with 160,000 miles on it from an auction, so we're pretty much in the same boat. I checked it over pretty close myself, and found the timing belt didn't look "new", so I had the dealer replace that.

I asked the dealer was other items I should expect to replace now or should do preventatively. The PCV system was the first thing they mentioned. They were able to do a vaccuum test on it -- no charge with my timing belt change -- and found that there was no pressure build-up. Maybe you can get a free "check-up".

The other item they mentioned was the angle-gear. That doesn't leak motor oil of course, but if you have a leak around that it woudl come out down behind the engine. I guess those are notorious for developing leaks, and then the gear fails as a result. They suggested I replace the seals now, but wanted too much for me at the moment.

I'm a newbie with these cars, but I hope that helps!

-AA

[rgaspar]

thanks for the suggestions in the previous posts to my issue....going to have the pcv checked asap. i suspect the previous owner was not very diligent about maintainence. rg