Transit High Crankcase Pressure

[Jesseholmes708]

Hi Team,

Bit stumped with this one.
Have a 2016 460e which has high crankcase pressure. Only realised due to an oil leak. Engine runs great and no smoke. Following has been done
Leakdown test - perfect result
Injector seals replaced
Rocker cover replaced- One of the little check valves was missing
Turbo oil return line disconnected and checked for pressure

Engine has had a recent egr and dpf delete carried out but I dont see how that could be contributing to this.

I have seen somewhere that the vacuum pump can fail and be pumping pressure into the crankcase area. Will test this tomorrow. Does appear to be more pressure out the oil cap than the dip stick.

With the oil cap removed there is the same amount of pressure as the turbo is producing at idle.

Any left field ideas would be greatly appreciated

[metalworker0]

Mini bus, according to google search .. so I assume 2.2 .. you must say this in your question

You've gone through and sorted all the things that could cause it

You need to plug it into a scanner to see if the turbo vane actuator isn't stuck on full and observe what the throttle valve inside the manifiold is doing.. that's the only things i can think of.

Some people have bought the wrong rocker cover which means the breathing is then messed up. The right one for this engine has the orange rubber check valves inside it.

And how were the deletes done .. was the DPF just put on ignore or taken off or drilled out was the EGR blanked off . this engine as far as i know, has a duel catalyst and dpf!

You've not done a compression test

i'm not sure of failure modes of the vacuum pump - point me to somewhere were they are saying it can cause crankcase pressure.

all the best.mark

[Jesseholmes708]

Thank you for your reply and input.

Yes sorry 2.2l UHR5 engine

The dpf was removed and chiselled out, egr blanked and re tuned. I think this may have been an issue before that as we did that while chasing a big oil leak on the intake side of the engine.

No I havent done a compression test. I would have assumed any issues would have become apparent during the leakdown. It also runs so well and smooth.

Double checked rocker covet and it is correct. Was replaced due to one of those check valves being missing.

Apparently the seal can fail in the pump and the air that has been sucked in on the vacuum side is then compressed into the rocker cover.

[metalworker0]

Sorry when you said leak down .. it got somehow converted in my head to leak off test .

I've nearly run out of ideas now, we will see how the vacuum pump test goes

what else

Sometimes the injector seats need re-cutting before replacing the washers.

When a turbos seals wear out, it can force the pressure down the oil return pipe into the crankcase.

Blocked exhaust

Leak down test. had to look this up on google, as ive only done petrol engine leak down tests, is done at least 100 psi or more on a diesel, otherwise will not prove what a compression test can prove, as far as worn bores or pistons are concerned. So, if everything else results in not finding anything out ... it's back to the compression test.

all the best.mark