Head Gasket issue?

[bluscreen]

Hello all,

Any suggestions on the next step from here?


I've had my car around 10 years and recently I let it sit for 4-6 months. It had been mechanically reliable until then.

Initially it would not maintain fuel pressure. After some troubleshooting I discovered the fuel pump's filter was completely clogged with goo. I cleaned out the tank, replaced the pump with DeLorean's new electronic one, and replaced the fuel filter. Seemed to fix the issue but now, if it sits for a while, a LOT of white smoke pours out the tail pipes right after I start it. Also, it's idle-hunting a lot. Especially if it rev the engine.

Besides that, if I give the car a decent amount of gas while sitting in neutral it will blow a fair amount of blue smoke out the tailpipes.

I have run a pressure test on the coolant reservoir tank and it showed normal, but I wonder if this is because the thermostat was closed. I also ran a compression test on the cylinders-- each got about 150 psi except one was 135 and the one next to it was 140. However, I was able to raise the 135 one to 150 by putting a teaspoon of oil into the cylinder. I hope this doesn't mean anything terrible.

The spark plugs, which only had about 2k miles on them, were all very black. I can't tell if its carbon or oil. It looks ever so slightly shiny but not really gummy or wet.

Lastly, when I changed the oil, the very last little bit came out like chocolate milk. Picture attached. Maybe it's just sediment? The car had been sitting for a couple weeks.
I broke open the lowest coolant connection and drained about a quart out but it looked very clean-- didn't look like there was any oil in it...

Sorry for the long post. I really appreciate the help here. I've read a few older how-tos on replacing the head gasket and it seems pretty involved.

deloreanoil.jpg

[Soundkillr]

You sure the smoke on startup isnt oil? Sitting for a while, and smoke on start up can be valve guides.

[bluscreen]

You sure the smoke on startup isnt oil? Sitting for a while, and smoke on start up can be valve guides.

I'm pretty sure it's not oil since its so white, but I'm not positive.

If its valve guides, is that something that might be fixed with a fuel cleaner additive? Maybe to remove some gunk there? Or is this something that would have to be fixed with the head off?

[Ron]

White smoke can be easily confused with steam, caused by condensation in the exhaust. Since you have changed the oil and made the above checks (They sound ~normal. No, closed thermostat doesn't matter for the test.), I'd suggest you install a new set of plugs and keep the engine running until it warms up. Let it cool, then take a look at the plugs to get your best clues at this point. (Keep track of which cylinder they come from...)

[bluscreen]

White smoke can be easily confused with steam, caused by condensation in the exhaust. Since you have changed the oil and made the above checks (They sound ~normal. No, closed thermostat doesn't matter for the test.), I'd suggest you install a new set of plugs and keep the engine running until it warms up. Let it cool, then take a look at the plugs to get your best clues at this point. (Keep track of which cylinder they come from...)

OK, will do! This sounds like a great idea.

Since it was quite a bit of white smoke, it is still a possibility that coolant is getting into a cylinder. Would this show on the spark plugs?

[Ron]

Plugs that look particularly cleaner than the others is a sign of coolant getting into the combustion chamber.
I should of mentioned that the current plugs might tell a lot too...

P.S. How long did the coolant pressure check hold and at what pressure?