Head gasket, or something else?

[Al Canuck]

Hey Guys,

I have a problem with my 85 535i, and need some help. A while back, I had some cooling system troubles, but seemed to have them all sorted out. Well, they seem to be back.

Problem 1) - Stays cool when driving, but heats up when idling.
Solution 1) - I ordered a new fan clutch from Steve Haygood.

Problem 2) - Loses a couple litres of coolant every 2-3 days.
No visible puddles, no steamy windows, no wet carpet.
Solution 2) - Head gasket?

Problem 3) - Start car when cold, and it pukes a few big clouds of bluish, whitish steamy smoke. Some days I think coolant, but then it will stink like raw fuel. Engine misfires pretty badly. After a few seconds of this, it clears up, runs on all 6, and pulls like a train. Doesn't happen again until I shut the car off, and let it cool down.
Solution 3) - Head gasket is weeping into cylinder(s), and burning off when I start the car? Or, injector is sticking open, and filling cylinder with gas, which burns off when I start the car?

Other items of interest is that it has 165psi in all 6 cylinders, no moisture under the oil cap, or in the dip stick. After a few seconds of running, it clears right up, and never skips a beat until I shut it down again. Plugs, cap, rotor, fuel filter, and FPR are all brand new. I have also pressure tested the cooling system, and it seems to hold in an acceptable range. Thermostat, rad cap, level sensor, and a couple hoses are all new. Mobil 1 15w50, and 320000km on the engine.

Any insight here guys? Please consider ALL the facts.

Thanx,

Al

[tacm]

White smoke not black? sounds like coolant to me if were fuel it wold be dark foul smelling exhaust its not unheard of to have weeping into the combustion without having water in the oil.....good luck!

[Al Canuck]

It's more blue/grey than white, and it doesn't have a sweet coolant smell. It STINKS like raw fuel. When my FPR went bad a couple months back, the huge clouds of smoke it was blowing were the same colour. Not black.

Al

[smackmybutter535i]

Yeah as long as the smake out the tailpipe doesn't smell like gas that is most likely your problem. If your coolant has a brownish tint to it that is definitleley your problem.

[tacm]

maybe a leaking cold start injector? mine leaks and waters down my oil...i have to change it every 2000 mi. Is you oil thin or smell like gas?...but where is the lost coolant going...i had a toyota once that had NO signs of haed gasket failure but leaked coolant into the exhaust system??????? just a thought


[Edit by tacm on [TIME]1109136852[/TIME]]

[Al Canuck]

Exhaust has STRONG fuel smell, as I stated a few times already. Not a coolant smell. Having said that, it is sometimes a pure white, and DOES smell a bit sweet.

No mixing of any fluids. No oily coolant, no watery oil, and no gasoline mixed into the oil, either. This one is a weird one. I'm a seasoned tech, with much German car experience, and I'm stumped here.

Al

[Bob in San Jose]

My guess is you have two problems. I'll go with the leaking injector for the fuel smell and a head gasket for the loss of coolant/sweet smell.

[Al Canuck]

[QUOTE="Bob in San Jose"]My guess is you have two problems. I'll go with the leaking injector for the fuel smell and a head gasket for the loss of coolant/sweet smell.[/QUOTE]

I sometimes start to think that as well, but there is one thing that bugs me about that. A couple of quick revs, and BOTH problems disappear in the same second. If it were headgasket, it would blow steam all the time. If it were fuel, it would always run rich. This latest tank of gas has turned in better mileage than it has in a long time.

Both problems go away instantaniously.

Al

[Walt]

Al,

Maybe you have 2 different issues, coolant loss and fuel.

Have you peeked under the valve cover for more discreet signs of fuel or water?

Any chance of a water leak at the overflow tank? Tried a dye?

I had an intermittent super rich condition due to a short in the wiring harness near the head/fuel rail sending WOT signal to DME. Wierd and difficult to diagnose.

You might try calling Dan Patzer in Mt. Vernon. He's a CCA tech, free advice. Decades of experience and he's owned/fixed lots of M30s. 425-743-2002.

Walt
ps Arm rest in the post.

[pdx 528e]

[QUOTE="Bob in San Jose"]My guess is you have two problems. I'll go with the leaking injector for the fuel smell and a head gasket for the loss of coolant/sweet smell.[/QUOTE]

[QUOTE="Al Canuck"]I sometimes start to think that as well, but there is one thing that bugs me about that. A couple of quick revs, and BOTH problems disappear in the same second. If it were headgasket, it would blow steam all the time. If it were fuel, it would always run rich. This latest tank of gas has turned in better mileage than it has in a long time.

Both problems go away instantaniously.

Al[/QUOTE]

Since the fuel problem goes away after revving, it points more towards a cold start valve rather than injectors or fpr; either that, or a build up of leaked fuel gets burned off, and then you are running rich but not smoking up. What did the spark plugs look like when you pulled them for the compression test? Perhaps the two symptoms are only related by coincidence.

EDIT: I missed the part about the plugs being brand new... oops.



[Edit by pdx 528e on [TIME]1109141698[/TIME]]

[Al Canuck]

Hey Walt,

I'm thinking that it is 2 different problems, and that maybe my head gasket isn't bad. I haven't tried a dye, but I did run a pressure tester on it a while back. I will pressure test it again, and see if anything has changed since the last one.

I think part of the problem is mental. I KNOW my car loses coolant regularly, and I KNOW my car puffs smoke/steam when I start it up. I think my head adds those 2 together, and comes up with head gasket. Next round of diagnosis, I will treat the 2 symptoms seperately, and see what happens. Pressure test for coolant loss first, and once that is accurately diagnosed, I will move to the next problem.

In the meantime, none of this has any bearing on overall performance of the car, as it still hauls enough ass to piss off some guy in 93ish Corvette on the freeway the other day! I couldn't pass him, but he had a helluva tough time trying to shake me, but I digress.

Al