Good Evening fellow DSMer's

First thing first. I know thick white smoke from exhaust means coolant. I know blue= oil, black = rich, light white = lean or blown motor .... Every other forum didn't have someone with a good compression or never came back on with their results...



Here is my setup so you know where I am with my vehicle.

420A motor rebuilted to a 2.4
Ross Piston
Crower Bullet Rods
HRC STG V Kit
20G turbo
All of the electronic goodies with it... (including wideband)

Alright. I did a compression check today and these were the result.

cylinder 1 = 180 (white tip on spark plug)
cylinder 2 = 190
cylinder 3 = 180
cylinder 4 = 190 (white tip on spark plug)

The result in my opinion came out good even with a little difference in range.

Next, i'm going to test the coolant system. pressure check it to see if there is any leaks.

Questions:
1. If compression test came back good, could it still be a blown headgasket?
2. If not the headgasket where else can coolant get into the cylinder?
3. Turbo is brand new but it comes with a little play which is normal...

Any suggestions??

Thank you for your time.

 

you sure its not oil? is it only when you get into boost?

 

Yes it can still be a blown headgasket. I think to check you do a leak down test.

 

i thought leakdown was to find the leak, not to tell if there was one.

 

How much smoke? It could be, as mentioned, a blown headgasket (although, generally, you would lose compression somwhere if oil were in the combustion chamber), valve seals, or a blown turbo (and still be white - white smoke doesn't always indicate coolant). What does the smoke smell like?

 

The smoke is thick white and irritates my eyes, and i can hardly breath. I basically have to hold my breath. For instance, it doesn't smoke as much when i'm driving casually but i still smell a little coolant. It's when i push the car a little. (my car still isn't tuned yet, and i don't pass 4000 RPM'S).

The return line on the turbo is fine. There isn't much shaft play with the turbo.

what i'll do is check the turbine side of the turbo to see if there is oil, but it still doesn't make any sense... the smoke would have a blue tint to it...

 

As was once explained to me, if it's only happening under boost then the added pressure from the turbo could be pushing past the head gasket. A leak down test will beable to simulate that added pressure, then also beable to tell if your losing it as though it were blown.


I could be wrong it wouldn't be the first time, but I believe this is accurate.

 

I had the same problem.I had a small hole in the head gasket.The hole grew and then finally gave out enough to make a difference in power.Just my .02

 

That makes sense to me. And that is the next step i'm going to take. Thanks.

 

The leakdown test will keep a constant pressure on the chamber and make small leaks evident that might not be in the quick pressure spikes of a compression test. A car could have a blown headgasket, burn coolant and pressurize the cooling system, but run fine and compression test decently. A leakdown test would put bubbles in the cooling system and show a loss of pressure.