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No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 08:44
by project25
Hi, Ive just rebuilt a 1984 DG 1.9 engine, It is now in and up and running but I have no oil pressure! Oil light stays on and hydraulic tappets dont pump up, ie it sounds like an air cooled.
Is end float critical? as I didnt have a gauge to set it.I read it can effect oil pressure. I have changed oil pressure switch. I am about to remove pressure switch and fire it up to see if oil comes out!
Hope someone is out there today and not enjoying their T25

Re: No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 09:48
by bigherb
Enfloat is critical but it should still have oil pressure. Possible the oil pump needs priming did you check it for wear or assemble it dry?

Re: No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 15:58
by kevtherev
tappets take ages to prime from new build unless you primed them first... you did prime them first I hope?

I'd be getting a mechanical oil pressure gauge and attaching it to the High pressure sensor (0.9 bar) next to the oil pump... you should see 50+ psi

nice intro.. :roll:

and welcome to the forum

Re: No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 18:54
by project25
Hi, thanks for replies.
Ive spent the day stripping stuff down to get at the oil pump. It isnt pumping, there is no oil in the filter, no oil in the pump. Haynes manual does not suggest priming the pump, how you supposed to do that? Is the pump pulling air from somewhere.
Ive rebuilt air cooled vw in the 70s never had pump probs ever.
Also stripping stuff off today meant I could also deal with a pin hole water leak.

Re: No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 19:35
by bigherb
If it is pulling in air it would only be from the pickup tube. The pumps don't normally need priming but if they are worn and dry it may. Normaly just pack some vaseline in the pump, remove the oil pressure switch and the spark plugs remove the green wire from the coil and wang it over on the stater motor until oil comes out of the oil switch hole.

Re: No oil pressure on rebuilt DG 1.9

Posted: 25 Apr 2011, 21:09
by kevtherev
does the pump turn OK .. when the crank is turned by hand?

Re: No oil pressure on rebuilt DG 1.9

Posted: 26 Apr 2011, 16:15
by project25
Hi, Annoying having to go to work, the pump does turn first thing I looked at.
I like the idea of cranking it over with plugs out etc. Im going to prime it by pumping oil in "backwards" from the oil filter hole. It has also been suggested that when I refit it I should use some thin sealer on the body of the pump.
Shall have to wait for another gap in my work. (self employed)