Head Gasket Leak???

[sdmelzer]

So I am super confused. I have white smoke coming from the exhaust. It smells sweet, like coolant, so I am pretty sure I am burning coolant. However, coolant levels don't seem to be dropping at all. Oil levels are steady as well. No coolant seems to be mixing with oil, and both fluids are clean. With the radiator cap of and the car idling, no bubbles are coming from the radiator.

Could this still mean a cracked or leaking head gasket given that the white smoke is the only symptom? I just cant think of anything else it could be, and the smoke is NOT water vapor. I would just think that a leak in the gasket would cause coolant levels to drop......

*Edit- Compression test done, results further down*

 

[t56speed]

Sounds like to me its rings in cyl 4. Good luck man.

 

[sdmelzer]

It seems like the problem is getting worse. I now have confirmed bubbles and oil mixed in my coolant. No coolant in oil yet. So it looks like the head gasket is leaking for sure.

So the only question left is, could both the head gasket AND the rings be bad due to the wet compression test results?

 

[BogusSVO]

With 170k you have some ring wear.

The rule of thumb is 10% from high to low. and your comp test shows that.

So unless you want to rebuild the engine.
Just fix the head gasket issue, put a few hundred miles on it and then run the comp test again.

 

[sdmelzer]

Will do. I'll report back once the headgasket is taken care of.

 

[BogusSVO]

Once you have the head off, post up some pics of the head gasket surface of the block and head and the HG.

 

[sdmelzer]

Took it to a friend's garage to do a hydrocarbon block test to make sure it is the head gasket before going ahead and paying for that to be done. Surprisingly, the test was negative. Awesome. One friend thinks its oil, the other thinks it is coolant. I am preparing to do a leakdown test in the next day to try to solve this once and for all. Will keep you guys posted.

 

[Passnu2]

before you tear it down are you able to do a leak down test?

edit: just saw your post as I was posting. I did this after the compression test and it helped out a lot.

 

[sdmelzer]

So the leak down test is complete. Results inconclusive - it seems like it may be the head gasket AND the piston rings. But I do have updated symptoms because I have been driving it a lot trying to figure out what the deal with the fluids is.


1. NO coolant loss. At all.
2. NO overheating. At all.
3. Very slow oil loss. It HAS to be burning oil somehow.
4. No external leaks.
5. Once the engine has been warmed, it will puff white smoke if you get on the revs. Otherwise, the smoke goes away (or is super wispy/barely there like steam) during idle and cruising.
6. Lots of smoke on morning startup.


I think it is more a ring problem than a head gasket problem. Since the oil s burning so slowly, do you think a slightly heavier weight oil would mend the problem for the time being? My motorcycle is now in the shop so I need the car for about a week or so.

 

[BogusSVO]

What you are discribing is classic of bad valve stem seals.

Bad valve stem seals will smoke during idle periods, stop lights, drive thu windows and the like.

Rings generaly smoke all the time, due to the rings losing the ablity to scrape the oil off the cylinder bore.

What was your percentage of leak down?

 

[sdmelzer]

My percentage was ~15% leak. Pretty small. And like I said, the only symptom is the smoke and slow oil loss. A question about the valve seals though - would they cause smoke if you gunned it? Because if I take it to redline, MASSIVE amounts of smoke come out. I thought that was indicative of rings?

EDIT - 15%, not 5. Sorry.

 

[BogusSVO]

At red line could be a combo.

But at 15% I would not be looking at the rings yet.

Valve seals could be bad enough to allow that much smoke IF the guides are about shot too. Put check your PCV, it may suck raw oil into the inlet tract at that point.

 

[sdmelzer]

I took the PCV off and it seemed like a regular amount of oil was on it, hose was clear, and it rattled. Worth replacing anyway just in case?

 

[BogusSVO]

As cheap as they are, I would.

If that is part of the issue, then it will smoke for a bit till all the oil has worked its way thu the air tract and burt out of the exhaust.