KV no oil pressure

Duffy3074 · 14-01-17, 04:12 PM

Hello!

My newly rebuilt KV lump is in the car and I thought I had nothing better to do spin it over on the starter and build some oil pressure up.

However, much spinning and backfilling of oil galleries later, checking of relief valves, sticking a mechanical guage that I trust into the place of the sensor etc etc, there's still nothing showing.

I didn't refill the pick up pipe when I put the sump back on.

Are KV's notoriously hard to build pressure up on?

Everything was well coated in graphogen when it went together so I'm comfortable that nothing's been damaged by the spinning.

Don't want to pull the sump off but it's the next step.

mikes2 · 14-01-17, 06:57 PM

It's not normally a problem.

Did you fit a new oil pump or was the original re-used.

Duffy3074 · 14-01-17, 07:38 PM

Quote:

Originally Posted by mikes2

It's not normally a problem.

Did you fit a new oil pump or was the original re-used.

I used the original as the engine was reported to have good pressure

It got a good clean and blown through with air just to make sure it was suitable to go back in

steve briance · 14-01-17, 09:31 PM

Seal between oil pick up pipe and block? If the gasket / o-ring is missing or damaged the pump will be sucking air as well as oil and if the air is easier to suck, it will suck it.

Duffy3074 · 14-01-17, 09:43 PM

Quote:

Originally Posted by steve briance

Seal between oil pick up pipe and block? If the gasket / o-ring is missing or damaged the pump will be sucking air as well as oil and if the air is easier to suck, it will suck it.

I remember the gasket going on as I used a smear of gasket seal on it just to make sure

Got me flummoxed this one, there's no oil pressure whatsoever!

steve briance · 14-01-17, 10:08 PM

Hmmm. It is an odd one. I rebuilt a 7a last year and had no problems with oil pressure at all,- no backfilling or anything, it just worked. Sorry, I know that doesn't help other than it does point to something being wrong

Def enough oil in it?
Def clear pick up pipe?
Oil pump drive engaged on end of crank shaft? I don't think it would bolt down if it wasn't but if he pump,wasn't spinning, that would explain it!

mikes2 · 14-01-17, 10:25 PM

As Steve indicates, there's not that many things it can be. When you turn it by hand on the front crank bolt, you can usually hear the suction as the pump turns

Think you'll be dropping the sump. Did your car have the black plastic part round the pickup ? Sometimes that can get knocked off when you fit the sump

Duffy3074 · 14-01-17, 10:37 PM

Black plastic pickup is on, the strainer was cleaned properly, its now overfull of oil due to the back filling, it does appear that the pump is doing nowt.
Saving grace is that the front subframe is still off so access is easy.
Guess what I'll be doing on Monday!

quattrostyle · 15-01-17, 04:54 PM

Maybe a silly suggestion, but is it not building pressure on the starter motor or did the engine run already?
Saying this as a friend of mine just rebuild his 2.2 10V and was worried that the engine did not built oil pressure on the starter motor but eventually connected everything and fired the engine up and all was fine.

4v6 · 15-01-17, 05:40 PM

Id go with a stuck pressure relief valve, thats why I always polish the bloody things on a rebuild as they can stick open and give low oil pressure, even though youve checked it, try it again.....you have got it in the right way round?

Hope you sort it soon, these kinds of problems are a real worrier.

14-01-17, 06:57 PM	#2
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	It's not normally a problem. Did you fit a new oil pump or was the original re-used. __________________ 1991 90 quattro 20v sport 1991 90 quattro

14-01-17, 10:25 PM	#7
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	As Steve indicates, there's not that many things it can be. When you turn it by hand on the front crank bolt, you can usually hear the suction as the pump turns Think you'll be dropping the sump. Did your car have the black plastic part round the pickup ? Sometimes that can get knocked off when you fit the sump __________________ 1991 90 quattro 20v sport 1991 90 quattro

14-01-17, 09:31 PM	#4
steve briance Newbie! Join Date: Oct 2016 Posts: 18	Seal between oil pick up pipe and block? If the gasket / o-ring is missing or damaged the pump will be sucking air as well as oil and if the air is easier to suck, it will suck it.

14-01-17, 10:08 PM	#6
steve briance Newbie! Join Date: Oct 2016 Posts: 18	Hmmm. It is an odd one. I rebuilt a 7a last year and had no problems with oil pressure at all,- no backfilling or anything, it just worked. Sorry, I know that doesn't help other than it does point to something being wrong Def enough oil in it? Def clear pick up pipe? Oil pump drive engaged on end of crank shaft? I don't think it would bolt down if it wasn't but if he pump,wasn't spinning, that would explain it!

14-01-17, 10:37 PM	#8
Duffy3074 4 ring whore! Classic Audi Club Member Join Date: Aug 2015 Location: Dalgety Bay, Fife Posts: 2,078	Black plastic pickup is on, the strainer was cleaned properly, its now overfull of oil due to the back filling, it does appear that the pump is doing nowt. Saving grace is that the front subframe is still off so access is easy. Guess what I'll be doing on Monday!

15-01-17, 04:54 PM	#9
quattrostyle 4 ring whore! Classic Audi Club Member Join Date: Feb 2010 Posts: 2,188	Maybe a silly suggestion, but is it not building pressure on the starter motor or did the engine run already? Saying this as a friend of mine just rebuild his 2.2 10V and was worried that the engine did not built oil pressure on the starter motor but eventually connected everything and fired the engine up and all was fine.

15-01-17, 05:40 PM	#10
4v6 Ex Member Classic Audi Club Member Join Date: Dec 2007 Posts: 5,565	Id go with a stuck pressure relief valve, thats why I always polish the bloody things on a rebuild as they can stick open and give low oil pressure, even though youve checked it, try it again.....you have got it in the right way round? Hope you sort it soon, these kinds of problems are a real worrier.