Troubleshooting blue smoke on a 2001 XC70

[DutchXC]

A few days ago the XC70 started to show blue smoke under load. Also the engine threw a few faultcodes.

The faultcodes were misfires detected on the first cylinder. This is probably caused by a bad coilpack. We changed it and the car is running smooth.

Now the problem with the blue smoke remains. When I check the turbo there is some oil hanging under it. Also when I do the latex glove trick on the dipsticktube it blows some air in the glove. When you rev the engine more air gets pushed into the glove.

We did a compression test on it and that all looks quite good. Also no oil in the coolant or vice versa.

When the engine gets warm some smoke flows from the area where the exhaust manifold sits. Can't really see where it comes from.

The AA guy thought it might be a blown turbo or a blown headgasket.

Can you guys point me in the right direction??

Should I start with cleaning the oil return pipe and the PCV system? What is involved in cleaning the PCV system?

[Astro14]

The blue smoke is oil being burned by the engine...and lots of it if you can see the blue smoke!

You don't really clean the PCV system as much as replace the components - and you need to do this ASAP. The AA guy? Who is that, exactly? He's completely wrong, by the way...it is the PCV (flame trap) system...it looks like this: http://www.ipdusa.com/products/4988/114177-pcv-breather-system-kit-1999-2001-c70-s60-s70-v70-xc70-turbo

Directions/description here: http://www.freewebs.com/howardsvolvos/engine.htm (scroll down).

Let me guess...bought it used, it gets 5W30 oil...but you don't know what kind, exactly, just as long as it's 5W30...right?

[JRL]

Also did you change plugs?
That previously fouled cylinder now has a fouled plug

[DutchXC]

why cant i reply?!

[sjonnie]

When I check the turbo there is some oil hanging under it.
Can come from lots of places, including oil line, air intake and charged air tube coupling.


Should I start with cleaning the oil return pipe and the PCV system? What is involved in cleaning the PCV system?
Start with the PCV system. Remove the components and clean out with kerosene, or replace with new components if you wish. I just replaced the crankcase hoses. You need to remove the intake manifold to access the breather box attached to the front of the crankcase, look for detailed howtos on this site and others.

[DutchXC]

We ordered all parts to overhaul the PCV system. Is there any way to check the turbo and take it out of the equasion?


Can come from lots of places, including oil line, air intake and charged air tube coupling.


Start with the PCV system. Remove the components and clean out with kerosene, or replace with new components if you wish. I just replaced the crankcase hoses. You need to remove the intake manifold to access the breather box attached to the front of the crankcase, look for detailed howtos on this site and others.

[sjonnie]

Is there any way to check the turbo and take it out of the equasion?
From your description, it sounds like the turbo itself is fine, a blown turbo smokes like crazy out the tailpipe. http://www.youtube.com/watch?v=-wXH9ScKIgI

Do your PCV job and see how much crud is in the crankcase drain & banjo bolt. If they're totally chocked up you might want to check the turbo return line. Otherwise I'd just do the PCV job and check the turbo hoses and go from there.

[DutchXC]

Yesterday we took apart the PCV system and that was FULL of carbon buildup. Both ports from the flametrap to the engine were cloged and the small hose from the inlet manifold to the complicated hose was blocked. We still need to build everything back to the car, but this should be atleast one problem down!

[DutchXC]

@ astro14 we currently have Shell Helix Ultra 0W30 full synthetic in the engine. Still looks clean after 10k miles. What would you recommend?

[DutchXC]

@JRL the plugs were changed 10k miles ago. Would you recommend a new one on the coil that failed? The plugs are Bosch Irridium @ $30.00+ a piece...

[Astro14]

The Helix Ultra is one of the best oils that money can buy. I have no recommendation beyond that...but has it always been run on Helix Ultra? PCV systems tended to get clogged on this engine if they've been run past the oil's life...in the case of Ultra, that's a long time, but I am curious how the Previous Owner treated it...

10,000 miles should be about the limit for the Helix Ultra...it can look clean but still be used up. It's a question of how much base is left to neutralize the acids...and that's not related to color. I would change it on the factory recommended schedule for your country...

[DutchXC]

Today we got the car back together. Only the bolt connecting the inlet manifold to the PCV hose was a b*tch to get in but otherwise everything went well. The car starts and runs fine, as of yet no smoke from the exhaust. We do still want to flush the engine with an additive that you add to the old oid and than dump it and replace it with new oil. We currently have 0W30 in it, would you recommend a different viscosity?

[Astro14]

Today we got the car back together. Only the bolt connecting the inlet manifold to the PCV hose was a b*tch to get in but otherwise everything went well. The car starts and runs fine, as of yet no smoke from the exhaust. We do still want to flush the engine with an additive that you add to the old oid and than dump it and replace it with new oil. We currently have 0W30 in it, would you recommend a different viscosity?

Shell Helix Ultra in 0W30 is as good as oil gets for this car, you cannot buy a better oil - pay no attention to what I've used...I got all that oil on sale for $0.98/Qt...that's right, less than a dollar per litre (I know what oil costs in Europe, and you have my sympathies)...I just bought several cases of Pennzoil Ultra 5W30 (same as the Shell Helix) on sale that will go in the Volvos next...for $1.98/QT...with the number of cars that I maintain, I am always looking for a good deal on oil.

Now, there should be absolutely no reason to use any kind of flush or additive with the Shell. If you stick with the recommended Oil Change Interval, and use the right oil, there is no sludge in the engine. Those flushes thin the oil and can degrade its viscosity. No good comes from flushing an engine that is already clean. The oil itself keeps the engine clean. I bought my wifes' XC with 92,000 miles on it, and now over 158,000 on it, the engine is perfectly clean inside. I've been using Pennzoil Ultra - (same oil that you have been using, different brand label over here) - it is has cleaned whatever was left over from the previous owner. No need for a flush. Ever.

Keep using that Shell Helix, it's a great choice!

[Allen]

Ultra is a fine oil.

[sjonnie]

We currently have 0W30 in it, would you recommend a different viscosity?
With the Dutch winter coming 0W30 is exactly what you need. I ran Mobil 1 0W30 all round this year, 7,500 miles between changes including about 3,000 miles of towing. In previous years I've switched to 0W40 during the summer but stuck with 0W30 this year for the better fuel economy. Absolutely no signs of increased wear or decrease in oil performance so I'm sticking with what works. Unfortunately I pay about $5 a quart.

Glad the PCV job fixed your problem.

[Astro14]

Sjonnie - I wouldn't complain about the price you pay - that's a good price.

In Europe, I bet he's paying over $20/QT...

[DutchXC]

Well a QT is about the same as a litre and the retail price is about $30.00/ltr

We found it online, via a german supplier @ about $10.00 a litre.

The new coils are in and the oil aswell as an engine flush are on their way. The previous owner did not change the oil regulairly and I think he used sub standard oil. Therefore we will flush the system.

[Astro14]

Well...I am not surprised on the price of oil. When I was in Germany last fall, I happened to see what was being asked...I nearly choked...

As I said before, I am not a big fan of flushing - the solvent involved in flushing tends to dislodge larger bits of sludge and dirt/carbon, potentially clogging up the oil pick-up (leading to engine failure) and the VVT solenoid (leading to power problems and requiring replacement of the solenoid).

You're better off letting the oil itself slowly dissolve the deposits. The Helix is known for cleaning engines and that same oil cleaned up my XC - which also had unkown maintenance history prior to my ownership.

Everyone wants a quick fix, sometimes the best thing to do is wait...

[DutchXC]

Today we fitted the new coils and took the car home from my workshop. The engine runs smoother than ever and in the 50 km drive home not a hint of smoke. Lets hope this was the cure to the problem. I will reconsidder using the oil flush... Would not want to make things worse!

Next jobs on the agenda are changing the hex-drive oil and investigate the faultcode it liberally throws on the fuel system. (tank lid not secure)

Thanks for the help so far!