Replacing the BMW valve cover gasket: gasket or complete cover?

A leaking valve cover on a BMW is a regular occurrence. At first glance the solution seems simple: replacing the valve cover gasket, refitting everything and done.

But especially on modern BMW engines with a plastic valve cover, a new gasket alone is not always the most sensible repair.

With this BMW M3 F80 with the S55 engine we saw an oil leak on the exhaust side of the valve cover. The car had covered about 120,000 kilometers and had always been dealer-serviced. Still, age, temperature and thousands of heating and cooling cycles can take their toll on the plastic valve cover.

Because the oil was leaking on the exhaust side, it also ended up close to hot exhaust parts. That can cause smoke from the engine bay and the typical smell of burnt engine oil.

For this BMW M3 we therefore chose not just a new gasket, but the complete valve cover.

How do you recognize a leaking BMW valve cover?

A leaking valve cover gasket can show itself in different ways. Sometimes you only see some oil or greasy dirt along the cylinder head. In other cases you smell burnt oil during or after driving, light smoke appears under the hood, or oil runs down the engine.

Especially when the leak is on the exhaust side, a relatively small oil leak can become quite a nuisance because the oil ends up on hot parts.

It is therefore important to first establish where the engine oil is actually coming from. Oil can spread across an engine block, which means that a leaking valve cover, for example, is sometimes mistaken for a different oil leak.

Replace only the BMW valve cover gasket?

A new valve cover gasket is of course much cheaper than a complete valve cover. On certain engines and under certain circumstances, replacing only the gasket is therefore perfectly justified.

But on modern BMW engines the valve cover is often made of plastic or composite material.

That cover is constantly heated and cooled throughout its entire service life. After many years and thermal cycles the material can warp, become more brittle, or the sealing surface can become less perfectly flat.

A new rubber gasket may be new, but it still has to seal against the old valve cover.

If that cover itself is no longer perfect, there is therefore a risk that the engine will start leaking again after a while.

Why we sometimes replace the complete valve cover

With a repair we do not look only at the lowest parts price.

We also look at the ratio between the cost of the part, the labor hours required and the chance that the repair stays solved for the long term.

When many parts have to be removed to replace a BMW valve cover, it can make little financial sense to save, say, a hundred euros on the part if that means the full labor cost may have to be paid a second time later.

For this M3 we therefore found the complete valve cover the more logical choice. The complete set we used also included the new seal.

So for us the question is not solely:

“What is the cheapest repair today?”

but above all:

“Which repair offers the best balance between cost, reliability and labor hours?”

On the BMW S55 the crankcase ventilation is in the valve cover

With the S55 engine of the BMW M3 F80, M4 F82/F83 and M2 Competition F87 there is an additional argument.

Here the valve cover is not just a cover over the camshafts.

In its technical documentation BMW describes that the components of the crankcase ventilation (PCV) and the blow-by channels are integrated into the cylinder head cover.

That means that with a completely new valve cover you are not just replacing the old sealing surface. At the same time you renew several parts of the integrated crankcase ventilation system.

Of course that does not mean the crankcase ventilation is faulty on every leaking S55 valve cover. It is, however, an important factor in the choice between a gasket alone and a completely new cover.

Plastic valve cover and heat

An S55 is a compact 3.0-liter six-cylinder with two turbos and many components close together. The valve cover therefore sits in a thermally heavily loaded environment.

We would not claim that every S55 valve cover is guaranteed to warp. That would be too absolute.

What we do take into account in our assessment is that, after many years and thousands of heat cycles, a plastic part does not necessarily still have the same shape and material properties as when it was new.

On an engine of higher age or mileage, that makes the case for a complete cover more interesting.

Replacing spark plugs as combined work

At the same time, on this BMW M3 the spark plugs and ignition coils were replaced.

That is a good example of how we try to handle combined work at BimmerStore.

When various parts have already been removed for one repair, we look at which other jobs can logically be combined. We do not like to charge for the same disassembly twice when it only has to be done once.

A technical workshop manual usually describes repairs separately. In practice, however, different jobs can partly overlap.

If part of the top of the S55 has already been dismantled for the valve cover, that can be the right moment to also carry out maintenance work that would otherwise require disassembly again.

We try to deal with that fairly in terms of hourly rate too. Maintenance work, repair work and specialized diagnostics do not automatically have the same rate with us. When jobs are combined, we try to actually pass that benefit on to the customer.

Striking difference in the old spark plugs

During disassembly we noticed something else.

The spark plugs fitted were tightened very unevenly. Some could be unscrewed with almost no force, while others needed considerably more force and we even had to use a breaker bar.

The car had an extensive dealer service history.

That does not automatically mean we know who fitted these spark plugs or under what circumstances. We cannot draw a reliable conclusion about that after the fact.

What we could establish objectively was that there was a big difference in the force with which the various spark plugs had been fitted.

That is why we fit new spark plugs according to the correct specification and installation procedure.

Genuine BMW, OEM or aftermarket?

With parts too, aftermarket does not automatically mean “cheap” to us.

There is a big difference between a random budget part and a part from the manufacturer that also supplies the same application to BMW.

This is nicely visible on this F80 M3.

BMW part number 12 13 8 616 153 is a Delphi ignition coil according to the parts information. The coils we took out of this M3 were also Delphi.

We therefore again chose the correct Delphi application, but directly via the aftermarket instead of necessarily in BMW packaging.

The same principle applies to the spark plugs. For this S55, BMW reference 12 12 0 039 634 / ZMR5TPP330 is used. The corresponding Bosch application exists for it.

That does not mean that every Bosch, Delphi, Continental or other branded part is automatically identical to the part in a BMW box.

That is why we check part number, application and specification.

However, when a correct component from the OE manufacturer is available, we can often offer the same quality class without the customer necessarily paying the full premium of the BMW sales channel.

• ​
• ​

PreviousNext

Cleaning is part of replacing a leaking valve cover

When a valve cover has been leaking oil for some time, that oil does not stay neatly against the gasket.

It spreads over the cylinder head and other parts, collecting dust and dirt along the way.

Before we fit the new valve cover, we therefore clean the relevant sealing surfaces and contaminated areas.

That is not only important for correct installation.

If old engine oil remains all over the engine block after the repair, it also becomes much harder later on to check whether there really is a leak again or whether you are just looking at old oil residue.

• ​
• ​

PreviousNext

When is a valve cover gasket alone enough?

So we do not blindly replace the complete valve cover on every BMW.

When the cover is in good condition, properly flat and there are no indications of damage, warping or problems with integrated components, replacing only the BMW valve cover gasket can be exactly the right solution.

In making the decision we take into account, among other things, the age and mileage of the car, the material and condition of the cover, the amount of labor needed to get to it and the price difference between the seal alone and a complete quality cover.

For this BMW M3 F80 with the S55 engine, that trade-off came out in favor of a complete valve cover.

What does replacing a BMW valve cover cost?

The price of replacing a BMW valve cover varies greatly per engine.

On some four-cylinders the cover is relatively easy to reach. On other BMW engines considerably more parts have to be removed before the valve cover can be taken off.

The difference between a valve cover gasket alone, a complete good-quality aftermarket cover and a genuine BMW valve cover naturally also affects the price.

That is why at BimmerStore we first look at the car and engine type individually. When maintenance work such as spark plugs or ignition coils can logically be combined, we also take the overlapping labor into account.

That way we try not only to repair in a technically correct way, but also to avoid a customer paying twice for the same work unnecessarily.

Can you keep driving with a leaking valve cover?

A light oil sweat does not automatically mean the car has to be taken off the road immediately.

A clear leak is something else.

When oil ends up on hot exhaust parts and causes smoke or a strong smell of burnt oil, we would not let the problem drag on for months. In addition, a leak can get worse and the oil level can drop.

So first have it determined how serious the leak is and exactly where the oil is coming from.

Need a BMW valve cover replaced?

Does your BMW have an oil leak around the valve cover, do you smell burnt oil or see smoke from the engine bay?

At BimmerStore we specialize in BMW and MINI. We first look at where the leak actually originates and then assess whether replacing the valve cover gasket alone is sufficient or whether a complete valve cover is technically and financially the better solution.

For a BMW M3 F80, M4 F82/F83 or M2 Competition with the S55 engine we can also carry out the valve cover and related work.

Contact us for a quote for your BMW.