exhaust fumes/smell from coolant reservoir

[chaseinger]

hi all,

after winter overheating i did the PVC and water pump on my 1998 v70xc. new belts, new t-stat, replaced a few hoses.

PVC overhaul including valve cleanout. new oil trap, new lines. as i put the intake manifold back on, i busted a bolt. i decided to finish the job and see what happens.

now, car starts and runs, maybe a tiny bit rough, but it runs just fine. lotsa steam (it's cold out, but still: LOTS) out of the tailpipe, and definite exhaust smell coming from the coolant overflow.

so here's the question: is it dead sure i blew the head gasket (i did run into the red) or could the symptoms, somehow, be related to the intake manifold issue? i'll do a compression test tonight and shall update.

[beigg]

so here's the question: is it dead sure i blew the head gasket (i did run into the red) or could the symptoms, somehow, be related to the intake manifold issue? i'll do a compression test tonight and shall update.

Please elaborate to the quoted above.

What is the background to doing all this maintenance?

[101]

The missing intake manifold bolt could be causing a small vacuum leak which could certainly lead to rough running and poor idle. It all depends how much of a leak is there.

The steam could be just condensation. If you're not having to add coolant to the tank, don't worry about that.

The auto parts places sell a kit to check for combustion gases in the coolant. I'd recommend that as well as the compression test before considering any engine teardown.

These engines generally hate overheating, but sometimes you can get lucky.

[chaseinger]

Please elaborate to the quoted above.

What is the background to doing all this maintenance?

i ran into overheat issues in the blistering cold due to a waterpump leak. limped home with a rather hot engine. while i was inspecting the damage i noticed oil on top of the head and so i did the old glove test. glove blew right up, and smoke coming from the dipstick. so i decided to do the PVC as well, after having purchased it with slightly over 100k miles and suspecting not a lot of service been done on it. and good: the old PVC on it was totally shot.

so water pump and mightaswell all the belts, plus PCV overhaul. new pump holds tight. plumbing sits well and no leaks. if it hadn't been for the darn manifold bolt tear off (and it's a middle one, too...) it would've been an all-round success.

[chaseinger]

The missing intake manifold bolt could be causing a small vacuum leak which could certainly lead to rough running and poor idle. It all depends how much of a leak is there.

The steam could be just condensation. If you're not having to add coolant to the tank, don't worry about that.

The auto parts places sell a kit to check for combustion gases in the coolant. I'd recommend that as well as the compression test before considering any engine teardown.

These engines generally hate overheating, but sometimes you can get lucky.

here's to hope, or luck. i'll do the coolant test kit this weekend i reckon, but if i can clearly smell exhaust fumes (and see it, too) and they bubble out of the overflow line into the expansion tank, in time with the engine rev, i'm pretty sure i got, y'know, exhaust gasses in my coolant.

unless the norse gods are with me and there's a reason for exhaust fumes getting into the coolant with a potentially substantial intake manifold leak.

[abscate]

I think the Norse Gods will demand their cylinder head gasket rework sacrifice.

I'm not sure I recall anyone seeing exhaust bubbling up from the reservoir? Ouch.

[chaseinger]

I think the Norse Gods will demand their cylinder head gasket rework sacrifice.

I'm not sure I recall anyone seeing exhaust bubbling up from the reservoir? Ouch.

not bubbling up, coming from the upper pipe, through the t-stat. but yeah. norse gods seem to demand a sacrifice indeed.

[splats]

Years ago, I had a head gasket go bad on a '69 Datsun Roadster (2000). When I drove down the highway, I didn't see much from the exhaust. But when I pulled up at a stop light, plumes(!) of steamy exhaust enveloped my car - it was an astonishingly large cloud. A compression test didn't reveal much - the crack in the gasket was small enough, and the viscosity of the coolant was great enough, that compression seemed ok. Not sure if that story is of any help, but what the heck.

[abscate]

We have had reports here of coolant leaks without bad compression test numbers, so the compression test should be taken as a confirmation of failure, but not a test that rules out head gasket failure.

[erikv11]

It's dead sure, this engine has a blown head gasket. Compression test may or may not be informative, exhaust gas check would be definitive, but you have your evidence already.

I once bought an S70 with a blown head gasket, exhaust gas bubbling out through the coolant reservoir. I swapped the engine.