Hi all
I hope there is a good tech on here to help?
Recently had oil pressure light come on and the engine suddenly stopped.
The engine has been part stripped, had 2x new camshafts and
Cam belt done new oil and filter and some cam follower things.
On starting up the oil pressure is good but as soon as the revs drop to idle it loses all oil pressure? Take it up over 1,200rpm and full pressure again.using seperate oil pressure gauge.

Any ideas?
The oil pump has been fully tested.

Could it be big end bearings or something in that area or an engine plug drooped out of somewhere?

Any pointers much appreciated.

Regards (GONE) FL2 2008 SE (manual) Santorini Black, the expensive one
(LEFT WITH) 300tdi Defender 90 the cold, reliable & sensible one

Did you check the big ends with the engine part stripped?
I bought my 2010 with engine knock. With the sump and oil pump off you can reach no 4 big end cap to remove. I tried unbolting the balancer unit to check the others however the balancer casting was larger than the spacer intermediate casting and would not come out.
No 4 big end shells had spun around and the crank was scored, yet with all this damage the engine ran, the car drove and the oil light extinguished as normal.
I would reccomend that you first check the big end(s) and find and replace the oil pressure relief valve; it might be in the ally front filter housing.
I fitted a 'new' engine bought off fleabay, see my notes on engine removal.
Hope this helps 2010GS Auto ex Celeb, Santorini Black, 2011 facelift , spoiler, spats, mudflaps, LED footwell lamps, Witter detach,
Other cars:-
1958 & 1959 Austin J40 Pedal Cars under restoration (I make many J40 parts)
If you have an Austin J40 or Pathfinder Pedal Car looking for a new home pls PM me.
2009 Meriva

Hi
The mechanic managed to check the big end on one accesible, with the balancer shafts in place and said it looked perfect no marks at all. Not sure about the relief valve think it has been checked.
He is about to do full strip down from the bottom think he needs some special tools to do something with the balancer shafts,maybe some of the other big ends maybe worn but until these are accessible we won't know.

Reading up, the most common cause of low oil pressure after all the other things check out is the big ends etc so it maybe the problem  (GONE) FL2 2008 SE (manual) Santorini Black, the expensive one
(LEFT WITH) 300tdi Defender 90 the cold, reliable & sensible one

Hi,

debris from damaged cams blocking oil pump pick-up screen or pressure regulating valve ? oil pump drive damaged (sprocket loose,key striped).I Don't think about damaged big ends as they usually start to make loud knocking noise long before they can cause the oil light to come on.Check your turbocharger for damage as it is very sensitive to low oil pressure.

Hi Ben,
Ive just read TOPIX on the oil pump, it should pump at 94.3psi and has an integral relief valve, IN THE PUMP), set at 116psi.
how does this compare with your remote pressure gauge? have you had the gauge calibration checked? The figures given above are what TOPIX says, it sounds incredibly high to my experience.
If you have no pressure at tickover then boy have you got an oil leak somewhere in the galleries or bearings.
My engine was allegedly wrecked by the preceding owner never servicing it in 34,000 miles and the oil being never checked until it ran out low and the engine was starved of oil. ive just reset the service indicator, it was 19,900 miles PAST its service interval. Ive had my pump off and seen the strainer so i dont think yours has seen debris through the pump because the mesh is too fine, i guess the relief valve may have stuck open.
The turbo outfeed banjo on the block has a beatifull long plastic fine mesh filter, i took mine out and cleaned it from inside out with a carburettor aerosol cleaner fluid, my turbo has survived starvation so its a good bet yours will have survived a bit of low pressure. 2010GS Auto ex Celeb, Santorini Black, 2011 facelift , spoiler, spats, mudflaps, LED footwell lamps, Witter detach,
Other cars:-
1958 & 1959 Austin J40 Pedal Cars under restoration (I make many J40 parts)
If you have an Austin J40 or Pathfinder Pedal Car looking for a new home pls PM me.
2009 Meriva

Hi Ben,
Before your spanner man strips any more, how about trying another oil pump?
I've got my base engine with pump still installed and I know it quickly made the oil light go out.
If you want to borrow it for a trial it's available, I guess it could be out with 45 mins work. I made a heavy card sump gasket when I was fault finding.
If my 'used' pump solved the pressure then you could source a new one; it would at least prove if the relief valve was the culprit. 2010GS Auto ex Celeb, Santorini Black, 2011 facelift , spoiler, spats, mudflaps, LED footwell lamps, Witter detach,
Other cars:-
1958 & 1959 Austin J40 Pedal Cars under restoration (I make many J40 parts)
If you have an Austin J40 or Pathfinder Pedal Car looking for a new home pls PM me.
2009 Meriva

Classic symptoms of a stuck pressure relief valve (but my experience is all with engines from the last century so beware my advice!) I would certainly check that. If you can get an oil pressure gauge on it it would give low reading on tickover but too high a reading at high revs.

Hi all
Thanks for all the info, I'm really thinking that a change of oil pump is possibly well worth a look especially the more I hear about a sticking PRV.
I do not want to step on his toes as he has had the pump out and independently tested but a few people keep mentioning the prv as the most common cause of the symptoms of low pressure on idle, not sure on the over pressure at higher revs though I do not know what the gauge readings were, can ask.
I will speak with the mechanic tomorrow before he starts a full strip down, see his thoughts on this.

Regards
Ben (GONE) FL2 2008 SE (manual) Santorini Black, the expensive one
(LEFT WITH) 300tdi Defender 90 the cold, reliable & sensible one

Thanks for the offer of your oil pump that is much appreciated, I will see what happens after a chat tomorrow

Kind regards
Ben (GONE) FL2 2008 SE (manual) Santorini Black, the expensive one
(LEFT WITH) 300tdi Defender 90 the cold, reliable & sensible one