535i '91 - oil in the coolant

[Tcdoe]

I know what you're all thinking, "it's the headgasket". But I've had it tested, no exhaust fumes in the cooling system, no bubbles in the expansion tank, engine oil is ok, performance is ok, exhaust fumes aren't white and the car starts up ok.
I've had the cooling system flushed a few times but the coolant always ends up creamy after driving a while. This seems to be the only symptom. What could be the problem, besides a broken headgasket or a cracked head (yikes)? What's the next logical move?

[Bruno]

When I found some oil in my coolant, it was after the 1st day of a 2 days at the track.
I went there the second day, and the car the overheating slightly when it was idling... I guess oil is not good for cooling.

I started working on the head as soon as I got home. Change the head gasket and never had a problem after that.

My car never had white smoke or loss of power. Good lick.

[Randell]

I have the same problem. 2 weeks ago the surface of the expansion tank was like mud, so every morning i would scoop out the crap and keep on driving. Now in the morning there's only a tiny little bit of oil in there, so obviously i'm not driving as hard as I was before. Either that or the oil is stuck in the radiator or something, but the temp needle is still at the halfway point... I keep one eye on it all the time!

My mechanic told me it's a crack in the oil gallery (?) in the head, but i have a feeling it's the head gasket. My oil is also perfect, no smoke, engine runs as it always has.

But I still think it's the head gasket. I think the coolant ranges from about 10psi to 15psi (might be way off here), and the oil ranges from around 15 to 55? Anyway, the coolant is never of a high enough pressure to leak through the headgasket into the oil, but if you drive it hard the oil will get into the coolant.

But while you've got the head off it might be an idea to get it checked anyway, then if there is a crack in it you could get it welded up.

Keep us posted, I'm going to keep driving mine very gently and keep a close eye on things, cause i don't have the time or money to get it fixed at the moment. Plus in the last few days my gearbox has started to play up, so I'm in no mood to pour money into a dying car...

[Bill R.]

car before it will dump out the pressure relief , so figure a minimum of 15psi and the oil pressure will hit and average of 35 to 45 but when you shut the car off the oil pressure drops right away but the cooling system stays pressurized for quite awhile which gives it plenty of time to push coolant into an oil galley when the oil pressure is zero.





I have the same problem. 2 weeks ago the surface of the expansion tank was like mud, so every morning i would scoop out the crap and keep on driving. Now in the morning there's only a tiny little bit of oil in there, so obviously i'm not driving as hard as I was before. Either that or the oil is stuck in the radiator or something, but the temp needle is still at the halfway point... I keep one eye on it all the time!

My mechanic told me it's a crack in the oil gallery (?) in the head, but i have a feeling it's the head gasket. My oil is also perfect, no smoke, engine runs as it always has.

But I still think it's the head gasket. I think the coolant ranges from about 10psi to 15psi (might be way off here), and the oil ranges from around 15 to 55? Anyway, the coolant is never of a high enough pressure to leak through the headgasket into the oil, but if you drive it hard the oil will get into the coolant.

But while you've got the head off it might be an idea to get it checked anyway, then if there is a crack in it you could get it welded up.

Keep us posted, I'm going to keep driving mine very gently and keep a close eye on things, cause i don't have the time or money to get it fixed at the moment. Plus in the last few days my gearbox has started to play up, so I'm in no mood to pour money into a dying car...

[h33bi]

Had a very similar problem. Bought a 1992 520 off ebay for £400. The car is immaculate with nice fox alloys on. After a few weeks i started having gearbox probs (ie losing auto fluid) . several weeks later im told the head gasket has gone due to mayo being in the coolant system which ended up bursting radiator coolant pipes. Full strip down with the head skimmed and new gasket fitted. Only when I had completed all this did i discover that the gearbox fluid is carried to the radiator and it was here where the real problem lay. The gearbox fluid was leaking into my coolant which was then carried to the engine. A rather expensive way to discover I had a faulty radiator. Worth checking if you are not convinced the head gasket has gone.

[Javier]

Javier


Had a very similar problem. Bought a 1992 520 off ebay for £400. The car is immaculate with nice fox alloys on. After a few weeks i started having gearbox probs (ie losing auto fluid) . several weeks later im told the head gasket has gone due to mayo being in the coolant system which ended up bursting radiator coolant pipes. Full strip down with the head skimmed and new gasket fitted. Only when I had completed all this did i discover that the gearbox fluid is carried to the radiator and it was here where the real problem lay. The gearbox fluid was leaking into my coolant which was then carried to the engine. A rather expensive way to discover I had a faulty radiator. Worth checking if you are not convinced the head gasket has gone.

[Tcdoe]

Good point, but doesn't that only apply to cars with automatic transmission?

Now 6 months after starting this topic the car still doesn't show any symptoms other than the oil in the coolant, which hasn't increased by the way. And I've been pushing her hard occasionally. I'm just gonna continue driving normally and if the gasket goes, then so be it. Even the worst case scenario isn't that bad, it's not like the m30 is a rare engine.

[bahnstormer]

so rather than change the head gasket, u're gonna risk the motor?
u can do a HG job for a low price, so just do it and see if it works...

[Tcdoe]

so rather than change the head gasket, u're gonna risk the motor?
u can do a HG job for a low price, so just do it and see if it works...

That's right, because I'm not so sure at all that it's the hg. Ofcourse I'll do it if it becomes obvious that the hg is gone, but the car has worked perfectly for 6 months now. It's unlikely that something will happen to the engine anyway. Plus, I have reason to believe that the hg was done about a year ago.

[callen]

In addition it will run soo much better once you do it. After the changing gasket my engine came alive.....course was able to clean pistons, valves and everything else.

[Randell]

thought i'd follow up on this one

i scooped the oily muck out of teh coolant resoviour every morning for almost 2 months... that was about 5 months/7000km ago, and since then there has been NO oil getting into the coolant in that time... coolant level is fine, temps are fine, engine has been running fine (up until 2 months ago, another story!)..

i had it in at a mechanic a few weeks ago for an idle problem (which is driving me insane, took it to the 4th person in 2 months today, i've had enough), and he said there were 'fresh water marks' at the back of the head, so maybe the head gasket will go eventually, but for now i don't give a crap cause i can't drive it anyway!