OM642 Repeated Vacuum Pump Failure / Oil Feed Issue

Page may contain affiliate links. Please see terms for details.

sutherland

New Member
Joined
Apr 9, 2014
Messages
18
Car
S320
We are now on to our third brake vacuum pump on a car with this engine and they are failing quickly, which may suggest that the oil is not feeding to the vacuum pump. I understand, however, that it is impossible go investigate this properly without removing the left cylinder head to check the oil feed.

Has anyone encountered such a problem with this engine in any of the 320 CDI cars? Could it be caused by carbon build up even although there are no other symptoms whatsoever of such a problem?

The other thing that puzzles me is that if the brake vacuum pump could be failing due to lack of lubrication and become stiff, would this not cause some kind of problem for the engine as it is cam driven?

Any experience appreciated.
 
I have the same experience on my cls 350 om642. Not enough vacuum produced, changed few pumps. Still no help. Have you sorted yours?
 
Just saw this seven years later. The problem on our car was that some wally had fitted an engine from an E280, which has different holes in the cylinder head for supplying oil to the pump, so the vacuum pump kept failing. Drilling a hole in the cylinder head cured the oil supply problem, but after that we returned the car to Mercedes for refund and they also paid for the repairs.
 
I have the same problem, I removed the front ball but it still does not supply oil, the pump can help me, please
 
Am aceeași experiență pe cls-ul meu 350 om642. Nu s-a produs suficient vid, s-au schimbat câteva pompe. Încă fără ajutor. Le-ai sortat pe ale tale
 
I have the same problem, I removed the front ball but it still does not supply oil, the pump can help me, please
 
Engines originally fitted to W211 with SBC have no vacuum pump fitted, and the oil drilling is blanked because it isn’t required. I’ve never seen one adequately converted to operate the vacuum pump correctly. Not saying it can’t be done, but I’ve seen people try, without success.
 
my engine came with a vacuum pump and without a vacuum pump, I changed it and this one was without a pump engine code om642 920
 
Engines originally fitted to W211 with SBC have no vacuum pump fitted, and the oil drilling is blanked because it isn’t required. I’ve never seen one adequately converted to operate the vacuum pump correctly. Not saying it can’t be done, but I’ve seen people try, without success.
Mercedes Glasgow did it to our car and it worked fine for a whole year, although we eventually returned the car to Mercedes and got a refund because due to the unknown engine change, they couldn't warrant the mileage.
 

Users who are viewing this thread

Back
Top Bottom