Bad rings causing white smoking?

[spyderdrifter]

I'm posting this here because I haven't found conclusive answers during my search for answers. So this is to have the answers posted here for me, but also for others who may come across the same.

Anyway, I did a compression test a couple weeks back and concluded my rings are on their way out after the wet test yielded higher #s. Surprisingly my Spyder still runs rather well. I built a boost leak tester 2 days ago and did the test just to varify my ring conclusion and sure enough it did. No worries there. My car smoked a little white smoke at random points over the past 2 months. The smoke out put has increased since installing my Apexi exhaust (since I no longer have a catalytic converter). The point of this post is this: can my bad rings be the reason for the white smoke. My head gasket is good (only a few thousand miles. Less than 5k), and I'm not loosing coolant. I am running through oil little by little, but I'm sure that's because I need to replace the front cover crank seal, and it does leak oil only in this location. Also during the BLT, I found my BISS and BOV to also be leaking, but that was at 15 psi, and my boost on reaches 11psi max. Don't think either of those would lead to the smoking, but knowing that info might be handy. I'm replacing the rings and BISS at the beginning of August, but any input on this that'll assist would be great. Just don't want to replace everything and expect the smoking to go away, and then it doesn't.



Oh one other thing that I forgot. Can bad compression increase fuel consumption?

 

[WES_393]

Anyway, I did a compression test a couple weeks back and concluded my rings are on their way out after the wet test yielded higher #s. Surprisingly my Spyder still runs rather well. I built a boost leak tester 2 days ago and did the test just to varify my ring conclusion and sure enough it did. No worries there.

The problem with the wet test is that the oil usually just pools in the piston dish and raises the compression. The only way to avoid it is to use a hose on an oil can to get oil on the cylinder walls.

And with a boost leak test, your always going to get air past the rings. Unless you set the cams so the intake valves are all closed or remove the cams.

What kind of head gasket did you use?

 

[spyderdrifter]

Well, when I did the wet test, I too though about that and syphoned oil into a drinking straw and used that to disperse the oil better than dumping it in. Likewise with the BLT, I knew some air would pass by the rings due to ring gap, and as expected it did. However, during the compression test, cyl 2 had the lowest psi. During the BLT, I pulled each spark plug when going through the cylinders, and when plug 2 was out, I couldn't build any pressure in the engine because the air flooded past the rings. The other 3 cylinders had the gradual pressure loss past the rings when their plugs were pulled after building up to 15psi. This confrimed my compression results.

 

[BogusSVO]

Now when you did the BLT w/ #2 plug out, did you rotate the engine over so all the valves were closed on that cylinder?

You could have been in the over lap of the cams and that would allow the air to escape.

Now since you were using a BLT like a leakdown test, you would have to have the engine on the intake stroke, so the air can fill the cylinder, if not the closed intake valves would have stopped the air.

Best to get your hands on a leak down tester and run it like that.

White smoke is water/coolant.

Burning oil is blue, close to white smoke with a blue tinge.

 

[spyderdrifter]

Now when you did the BLT w/ #2 plug out, did you rotate the engine over so all the valves were closed on that cylinder?

I did not since I didn't think about it. How would I know the valves are in the right place, TDC?

I know what each smoke color indicates, but if I'm smoking white (and I know for sure its white), and I'm not burning coolant, leaking coolant, and the coolant system is working perfectly, then what can be causing white smoke?

 

[BogusSVO]

Pull the VC, then rotate the crank until you see the valves closed on the cylinder you want to test.

 

[JacksonAuto]

Sometimes it can be difficult to distinguish between white coolant smoke and blue oil smoke. I'd do a leakdown test on each cylinder to rule out the piston rings as being the problem.

 

[spyderdrifter]

Thanks Dale, I'll go through it again that way.

As for the smoke, I know the difference in color. My last DSM smoked blue because the turbo was eating itself. I know for certain its white. I can't get more sure than each time I'm crouched by the exhaust exit seeing white plume from the muffler. It's so white that I can tell by looking in the mirrors. I'm not trying to be dismissive of it being another color, but it isn't another color. I don't know how much more I have to say, it's white. Not gray, blue, or black.

 

[Calan]

If it's definitely white, I would start looking at a pressurized coolant system test, or a more thorough leak down test as Dale mentioned.

How much load or boost are you pushing when it smokes? Sometimes a head gasket can leak/fail under high load, but it won't show up on a standard compression or leak-down test.

 

[spyderdrifter]

It'll smoke a little at idle, then makes a few puffs on acceleration and stop smoking when giving boost. I'm only running on stock boost pressure and my boost gauge ranges from 9-11psi @ WOT. On occasion, it'll burp out a little smoke while passing someone. When I replace the rings next month it'll get a new HG as well since I'll never reuse one, even though this one has under 5k miles. Still won't reuse it.

 

[Calan]

It'll smoke a little at idle, then makes a few puffs on acceleration and stop smoking when giving boost.

Unless you have water in the oil and are burning it via an oil path (rings, valve seals, etc)...you're symptoms aren't making any sense to me; unless the smoke you are seeing is just burning oil. In that case, the symptoms mentioned above sound more like leaking valve stem seals.

It has been a long day though.

 

[spyderdrifter]

Believe me, the symptoms don't make sense to me either. Which is why I'm lost with it. I do periodically check the oil for coolant and have found no evidence of the two being mixed. The valve seals are as old as the HG.

 

[Calan]

In my experience, when burning oil/water symptoms pop up with no obvious cause, and all testing is inconclusive.... you can bet good money on a head gasket issue.

 

[spyderdrifter]

I did some testing last night at school that verified having bad o2's. I already knew I needed a new one, but the readings and research I did after showed it. The night before I went for a drive and my cel came on, for the first time since I replaced the CAS, about 3 months. So I scanned it and had a P0170 fuel trim bank 1. Later on I was doing scans that were unrelated since it was for my class, and had to camp are short & long term fuel trims. My long term was +12.5% and it didn't change with the perameters of the test. I later did the research for the code and found that the ecu will read +/- 12.5% if the unstream o2 is requesting more fuel than the ecu can deliver (12.5% being the max the ecu will deliver). I haven't explained it as well as the posts I read, but that's basically it. Was also told by someone else that the smoke, even though white, smelled like oil. I have only noticed the fuel smell in it since I'm notable to pick up on all smells (thanks to deployment to Iraq when I was in the army), so now I gotta see if my oil tastes like fuel. If so, that should explain the white smoke and my poor fuel economy (along with the o2 causing a rich mix condition).

 

[JacksonAuto]

So it's not burning coolant afterall. Huh.

 

[spyderdrifter]

Yep, no burning of coolant.