Oil leaking everywhere

[mbpharoh]

Hi Guys,

First post to the forum and my first BMW 128i 3.0i 6sp manual (I have a C300 AMG PKG auto as my daily). Picked up a 2008 128i 3.0 6sp manual with 120K miles on it for what I think is a steal, as I knew it required some work.

Upon opening the hood there was oil everywhere and a muddy like substance in the coolant tank. I uploaded some pictures, can you guys take a look at it and guide me to what may be wrong and how much it'll cost to fix. I drove the car today about 30 miles and it didn't overheat, just a light smell was coming out of the exhaust.

Cheers!

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[captain slowly]

Obviously, you should investigate exactly where the oil leak is, but if I had to guess, you probably have a leaking and cracked valve cover and oil filter housing gasket, as those are pretty much a given in these cars. I would then change the coolant with OEM BMW coolant and remove that ghetto intake and put the stock one back on then go from there.

P.S. You don't have a "AMG package C300". What you have is a C300 with the sport package, which includes wheels that say "AMG" on them and different bumpers. There literally is nothing AMG about it.

[Dackelone]

Well... you shouldn't be driving the car when you have oil and coolant mixing. Best case your oil cooler has a crack and oil(under pressure) is pushing its way into the coolant. Worst case is coolant is mixing with your engine oil and there goes your engine's bearings. I suppose the two fluids could be mixing at the headgasket.

I would change your engine oil... flush your coolant and see what's what. Or have the car towed to a shop and see what they say. There are kits that can test for a leaking HG. But I suspect its your oil cooler(next to the oil filter) or your OFH(oil filter housing) gaskets that have failed.

Are you sure the oil cap was all the way on? That could account for all the oil around the engine bay.

At this mileage you might also think about changing the waterpump and thermostat too. Look over all your hoses for wear/hardness.

good luck,
Dackel

[chris_flies]

You have the 3-Stage Intake manifold, meaning you either have an N51 motor (SULEV), or the car was tuned (likely, because that intake looks nice).

I'd point you towards a pretty bad failure of the Oil Filter Housing Gasket. FCP sells a whole kit to do this for $22 bucks, and since you're pulling the housing off, you might as well do a full coolant flush (drain - fill with water and cleaner - run car to temp - drain again - fill with actual coolant) and an oil change (you're near 120k, so that puts you on an even number).

The OFHG failure can have similar symptoms to a head gasket failure (highly unlikely unless car has overheated) because oil and coolant are running right next to each other, and the gasket just fails.

I'd also look into replacing that expansion tank, it looks like there's a lot of nasty gunk in there, and your hoses may also be gummed-up now because of it...

[Mr Gasser]

coolant runs through the oil filter housing as well as oil, if that is leaking it can combine the two, dumb design but there you go...

[Happy Jose]

Actually it isn't. Coolant warms up much faster than the oil. The idea here is to use the coolant's heat to help bring up the oil temperature.

When the car is fully warmed up, the oil will be at a higher temperature than the coolant. In this case, I think there will be a transfer of heat from the oil to the coolant.

What's bad here is the gasket or whatever isolates the oil from the coolant.

[chris_flies]

Originally Posted by Happy Jose

Actually it isn't. Coolant warms up much faster than the oil. The idea here is to use the coolant's heat to help bring up the oil temperature.

When the car is fully warmed up, the oil will be at a higher temperature than the coolant. In this case, I think there will be a transfer of heat from the oil to the coolant.

What's bad here is the gasket or whatever isolates the oil from the coolant.

Exactly!

I'm replacing my housing (soon, hopefully) with the large water-oil heat exchanger on it from the high-load N52 motors. The biggest difference is that it has a whole multi-plate external heat exchanger that allows for more efficient heat transfer between the fluids.

[mbpharoh]

Originally Posted by chris_flies

You have the 3-Stage Intake manifold, meaning you either have an N51 motor (SULEV), or the car was tuned (likely, because that intake looks nice).

I'd point you towards a pretty bad failure of the Oil Filter Housing Gasket. FCP sells a whole kit to do this for $22 bucks, and since you're pulling the housing off, you might as well do a full coolant flush (drain - fill with water and cleaner - run car to temp - drain again - fill with actual coolant) and an oil change (you're near 120k, so that puts you on an even number).

The OFHG failure can have similar symptoms to a head gasket failure (highly unlikely unless car has overheated) because oil and coolant are running right next to each other, and the gasket just fails.

I'd also look into replacing that expansion tank, it looks like there's a lot of nasty gunk in there, and your hoses may also be gummed-up now because of it...

Any way to test if there is leaks in the OFH area? I'm planning to clean and degrease the engine bay first so it's visible and can pin point that's the root cause of my problem.

[Zombie_Head]

Originally Posted by Mr Gasser

coolant runs through the oil filter housing as well as oil, if that is leaking it can combine the two, dumb design but there you go...

Its a smart design actually, all 70s and 80s water cooled Porsches used that system as well, and yes they also leaked however internal leaks, meaning the oil and coolant were mixing without any external leaks from the housing itself.

[chris_flies]

Originally Posted by mbpharoh

Any way to test if there is leaks in the OFH area? I'm planning to clean and degrease the engine bay first so it's visible and can pin point that's the root cause of my problem.

If you drive a fair distance after cleaning, you may notice some oil on the front of the engine (generally fuzzy-looking, because dirt gets mixed-in), but it usually will run down and behind the housing, and kind of follow along the lip on the head gasket. That's the general telltale sign of an OFHG leak.

[Mr Gasser]