Seeking some Practical info - head gasket - oil leak - torque specification for headbolts - BMW 325is

My car leaks about 1 quart every 1000 miles or so.

I first looked at the oil pressure sensor as I understand that is a common point of failure where oil leaks are concerned. But it was good.

It doesn't look like the oil is coming from the coming from the valve cover gasket, oil filter housing, or oil pan - based on what it looked like after steam cleaning.

The car runs very good.

There is leaked oil distributed evenly around the the lower part of the engine. So I guess this would indicate that my rings are in good shape and that my loss of oil is from the head gasket. It sure look likes it.

The car has 230,000 miles on it. The head was re-built at 160,000 miles after the car overheated.

One suggestion was to get the tightening sequence and torque spec on the head bolts and tighten the head.

I obtained the "Cylinder Head Assembly Specifications."

They are:

Step#1 - 22 ft-lb Step #2 - Torque angle 90 degrees Step #3 - Torque angle 90 degrees

The proper tightening sequence is also provided.

I have 3 questions:

Q.1. - Since these specs are for assembly, it would mean (I guess) that a new gasket is being used. And this might mean that the specs are not really applicable to my situation since the gasket I have has been in service for a long time. Or it might be that these specs only apply to a situation where the head is completely dissassembled. Does anyone know?????????

Q.2. - I would guess that what the specs say is that every head bolt is tightend in the proper sequence to 22 ft-lb, then 2 more sequences are performed where a quarter turn is applied to each bolt. Is that what the specs are saying????????

Q.3. Heck- what if I just tighten the bolts uniformly in the proper sequence in an effort to stop the leak???????? Would there be any great harm in that?????

Thanks in advance.

All responses are appreciated.

- Ben

Reply to
Ben Martin
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Have you considered the valve seals breaking down? Does the car smoke after sitting in traffic for a few min and then accelerating off? This is common on these small block six cylinders.

Reply to
daveck2

Where are the valve seals?

Do you know where I could find a diagram? Would it be in the Bentley Manual?

If the valve seals fail, would it look just like a head gasket failed, based on the location of the oil leak?

I don't think my car smokes at all. If it does I have not noticed it.

The car seems to run extremely well. It's just that it leaks oil. It's all over the lower part of the engine.

I infer that if the valve seals leak, one would expect smoke. Is that right?

Thanks in advance.

- Ben

Reply to
Ben Martin

Yea, it would smoke at least when you accelerate after idling for several seconds. The valve seals are on the valves and are internal to the head. It doesn't sound like this is your problem. You may have to use leak dye a black light to find the leak. The easyest thing to do is take it to a car wash and High pressure wash the engine, top and bottom, spend a few bucks and spray it down with engine degreaser and spray it again. Your engine will be clean and you can let it idle in your driveway and watch out for where the leak begins. I doubt it is your head gasket, your water will leak before your oil would, you would have oil in your coolant or steam coming out of your exhaust. your performance would also be down.

Reply to
daveck2

The tightening sequence you recite is for NEW head bolts. It doesn't really matter whether it's for a new head gasket or not; however, these head bolts are designed to STRETCH as they are tightened. Because of this, *they may not be reused*. If you're using old head bolts, replace them before using this tightening sequence.

-- C.R. Krieger (Been there; drove that)

Reply to
E28 Guy©

Get another opinion before doing anything to the head. In my experience an oil leak from a head gasket is a few drops in one area, not something that would end up all over the bottom of the engine. Also it is characteristic of particular engines, those that have an oilway very close to the edge of the gasket.

Reply to
Dan Buchan

Yeah, it could just be a valve cover or timing cover gasket. Not nearly as serious as a head gasket.

Reply to
Fred W

What do you mean by 'lower part'? If it's just around the pan, the pan gaskets on these engines are commonly known to leak. That's a lot 'nicer' job to do than some of the other things you're contemplating. As well, if it's coming from the front, I'd look at the crank seal area.

-- C.R. Krieger (Been there; done that - last summer, in fact)

Reply to
E28 Guy©

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