Smoking T5

[jbathmaker]

Hi All;

Suddenly, about a week before Christmas, my T5 motor started smoking badly. Huge clouds of smoke are emitted from the tailpipe at startup and while the car is warming up. The smoke is a very pale whitish grey colour. At the same time the oil consumption went way up. Interestingly enough, after a 1/2 hour run on the highway (about 70 mph) the smoking was barely evident when I stopped to buy gas.

I did a spark plug check this a.m. and the plugs were all poster boys for perfect plugs. The insulators being a very pale grey colour. There was no burnt oil or anything like it on any of the plugs.

Any suggestions, thoughts or whatever would be appreciated. Thanks.

BTW, the T5 motor is in an XC90 but since it's the same thing as an XC70, I have posted here as there seems to be a lot more people hanging about this forum than the XC90 one.

Regards,
Jon Bathmaker

[BLUEH20]

Have not had the top off a T-5 to verify the seals used on the valve guides. The problem you describe is classic valve guide oil seal failure. Should the valve guide seal fail oil will leak down into the combustion chamber as the engine cools.

The seals are usually bronze or some softer alloy and can fail at early milage--have seen it at 40K miles in my personal Toyota Celica--and I can assure you that it was maintained guite well; I just got unlucky.

The best insurance for this--good luck, good synthic oil changed often.

[JRL]

Or his turbo is going.....

[Aviator]

Oil burning will produce blue smoke....not pale whitish grey.

Dave.

[BLUEH20]

Missed that clolor I did--whiteish--water?

[4033]

wouldn't a head gasket failure produce the same white smoke?

[jbathmaker]

Hi Guys;
Thanks for all your help. I think we have eliminated burning oil and too rich a mixture because the colour of the smoke is wrong and the plugs were pristine.

I am leaning towards the burning coolant theory myself. However, I've just fried some engine coolant on my stovetop and it doesn't smell like the smell that comes with the smoke. It doesn't smell like traditional anti-freeze either. Also the coolant level is at min when the car's been sitting for two days in the freezing cold.

The car doesn't seem down on power at all but that may not mean anything as when my daily driver was an Impala SS it always seemed down on power but now I'm in a Honda Insight it always seems strong <g>.

Curiouser and curiouser as Alice said.

BTW, how would a dying turbo cause smoke ???? Thanks.

Regards,
JB

[Aviator]

If coolant is getting into the combustion chambers, the plugs WILL be in pristine condition. That's just a natural steam cleaning going on. A spark plug in a normal chamber always has deposits on it from normal combustion. All engines burn oil as well in case you didn't know that; again, a normal byproduct of combustion. As far as the turbo goes....when the bearing seals leak oil really bad, the oil is pretty much slingshot fed into the engine. Oh...frying coolant and burning it won't have similar odours....one is being burned with fire, and the other just latent heat. Are you getting any oil in the coolant, and vice versa?

Dave.

[jbathmaker]

Thanks Dave, your answer makes sense to me. I remember reading about an after market water injector kit in the early days of turbo charging cars and one of the secondary benefits was the steam cleaning effect.

Anyone know why the smoking stops after the car has been driven on the highway for about half an hour ?

Sadly, I'm going to need a lot of help getting up for a head gasket change in January in Ontario. <g> I would have thought that a firm like Volvo would have O-ringed the bores and have done with it.

Thanks.

Regards,
Jon

[billr99]

Anyone know why the smoking tends to stop after about a 1/2 drive ?

Sadly, I'm going to need a lot of help getting up for a head gasket change in January. <g> I would have thought that a firm like Volvo would have O-ringed the cylinders and have done with it.


If you have a head gasket that is going bad, then it is possible that when the engine is fully warm the expansion of the head and block seal the leak. I've had this occur on both a SAAB 9K and a VW Wasserboxer Van. Both had hair-line cracks in the head gasket (or the ring gasket in the case of the latter). You can try sealants, etc but the only fix is replacement of the offending part.

As far as "o-ringing" an engine, I can't think of one volume manufacturer who does that. Racers do it, but not OEM as it is too time-consuming to deal with on the line. Properly design the engine and specify proper maintenance and you really don't have to.

Good luck,

Bill

[Blessyouboys]

Sadly, I'm going to need a lot of help getting up for a head gasket change in January in Ontario. <g> I would have thought that a firm like Volvo would have O-ringed the bores and have done with it.


Have you done a compression test on the motor?

[jbathmaker]

Haven't done a Compression Test. I think I will need a screw in type to get into the T5's plug holes.

Does a duff head gasket show up on a compression test ?

[dpaton]

Large head gasket leaks will show, hair-lines not likely.

You could try constant pressure tests (and add a little oil through the spark-plug hole for a better seal). I use an air-tool quick-connect welded/brazed to a spark-plug bottom. Listen closely at the coolant cap for bubbles.

A coolant-system pressure test may help identify the issue.


Dann