MajorCommonFluid Leaks

BMW 4 Series: N55 3.0T valve cover gasket and PCV valve cover oil leak (435i)

N55 3.0T valve cover gasket and PCV valve cover oil leak (435i) is a common fluid leaks fault on the BMW 4 Series on the 2013–2016 cars, and we rate it major. Putting it right costs $900 to $2,400 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 22 documented faults on the BMW 4 Series.

Vehicle: BMW 4 Series
Engine: N55
Years: 2013–2016
Fuel: petrol
System: Fluid Leaks

This page covers the BMW 4 Series as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All BMW 4 Series faults22 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Rocker / valve cover or PCV / oil separator yet. We would rather show none than show a picture of a different part.

What goes wrong

The N55 3.0 litre turbo petrol six in the F32 435i has a known issue with the rubber valve cover gasket hardening and leaking, and the plastic valve cover itself can crack with age. The PCV valve is built into the valve cover and cannot be serviced separately, so a failed PCV or cracked cover means a new valve cover assembly. Oil weeping onto the hot exhaust manifold gives a burning smell or smoke and can reach the spark plug wells. There is no recall or extended warranty for this.

What you would notice

Burning oil smell after driving
Light smoke from the engine bay at idle
Oil residue along the valve cover edge
Low oil warning between services
Misfire from oil in the spark plug wells

How to check it

Where to look. Top of the engine, valve cover above the exhaust manifold

Open the bonnet after the test drive and smell for burning oil; look along the edges of the plastic valve cover and down toward the exhaust manifold side for wet oil or baked-on residue; check the oil level; ask if the valve cover or gasket has been replaced and when. If a workshop inspection is possible: check the plug wells for oil and the valve cover for cracks and a failed PCV diaphragm.

Parts involved: Rocker / valve cover, PCV / oil separator.

What it costs to put right

$900 to $2,400 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the valve cover or valve cover gasket been replaced, and do you have the invoice?”
“Have you noticed a burning oil smell or needed to top up oil between services?”

Now check the BMW 4 Series you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

BMW 4 Series buyer questions

Is n55 3.0t valve cover gasket and pcv valve cover oil leak (435i) serious on a BMW 4 Series?

We rate it major and common on the BMW 4 Series. The N55 3.0 litre turbo petrol six in the F32 435i has a known issue with the rubber valve cover gasket hardening and leaking, and the plastic valve cover itself can crack with age. The PCV valve is built into the valve cover and cannot be serviced separately, so a failed PCV or cracked cover means a new valve cover assembly. Oil weeping onto the hot exhaust manifold gives a burning smell or smoke and can reach the spark plug wells. There is no recall or extended warranty for this.

How much does it cost to fix on a BMW 4 Series?

$900 to $2,400 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which BMW 4 Series years are affected?

Our research records this fault on the 2013–2016 BMW 4 Series. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.