Engine: D5244: D5 Vacuum&Boost Diagnosis - What pressure to expect?

[davebb]

Hi have you done any tests on your glow plugs, with a multimeter,
they turn on from 7c down,
is your battery good? can you test what the lowest voltage is when starting the car, if it is -5c were you are that does not help
Dave

[davebb]

also get your self a mityvac pump, very handy for testing your car,
Dave

[Konstantine]

Dave,

I have not done any tests considering the battery or the glow plugs.
I have noticed the same behaviour @ 10-15°C.
The suboptimal starting behaviour is that it needs approx. 5 turns
if cold instead of 2 turns if warm.

I am trying to focus on the vacuum-pump Issue, because if it is
not the vac. pump, it may be broken hydraulic lifters...
...what would not make sense is that the popping almost disappears
when disconnecting the brake vac. hose.
I have found this symptom a couple of times in various forums,
but unfortunately no solution for the problem or a successful
diagnosis of this symptom.

Arrrgh. It's a bit mind bending.

Cheers, Konstantine

[davebb]

Originally Posted by Konstantine

Dave,

I have not done any tests considering the battery or the glow plugs.
I have noticed the same behaviour @ 10-15°C.
The suboptimal starting behaviour is that it needs approx. 5 turns
if cold instead of 2 turns if warm.

I am trying to focus on the vacuum-pump Issue, because if it is
not the vac. pump, it may be broken hydraulic lifters...
...what would not make sense is that the popping almost disappears
when disconnecting the brake vac. hose.
I have found this symptom a couple of times in various forums,
but unfortunately no solution for the problem or a successful
diagnosis of this symptom.

Arrrgh. It's a bit mind bending.

Cheers, Konstantine

Hi if popping stops with the brake vac line disconnected, if the pipe from the vacuum pump is not plugged to stop leaks, then you will not have any vacuum
take the brake booster pipe off the vacuum pump and plug/seal the that port on the vacuum pump, if you still have popping it is nouthing to do with the brake booster or one way valve,
and you have a leak some were, as the vacuum pump is always running with the engine you only need a very very small leak, WITH A BIG LEAK THERE IS NO VACUUM
so get a mityvac hand pump to test all pipes and engine mounts and solenoids and turbo actuator, with the hand held pump you can apply the vacuum an then stop pumping and see if the vacuum holds,
if you try and do this using the car vacuum pump it will be very hard to do as it is always trying to make vacuum,
you could do it with the cars pump and a gauge but you would have to block the pipe from the pump and disconnect it from the pump and make shore it is not leaking there,
so it is bet to use a mityvac hand held pump with gauge,
Dave