oil pressure drops at fast acceleration

[pasbogdan]

what fast means? g forces?high revs,or getting fast high revs(in lower gears,or standing)

[Ryss]

Is your oil pressure gauge wired up correctly and/or 100% accurate?

[quattro-nick]

@ driftin jo: i get full boost 1.6 bar at 3500 rpm and stays untill 7000 rpm
it's strange actually,i have no peak at all,it begins with 1.6 bar on 3500 rpm en stays
My egt is not higher than 800 degrees measured just behind the turbo
once with boost tuning on vems,i had a peak of 1.9 bar on 3500 rpm en drops to 1.7 bar untill 7000 rpm,i think its possible because i read it somewhere on this forum.
my boostgauge in the car is exactly the same as the boostgauge on vems


@ pasbogdan: fast means When the car pulls up in 1-2-3 gear with full boost on 3500 rpm,then drops my oilpressure from 5bar to 2 bar until I switch from gear
When I'm in 5th gear at 2000rpm and then give full throttle and I get full boost, drops my oil pressure not because my acceleration is then slower than in lower gears


@ ryss:I have measured my oil pressure with a mechanical meter and this gives the same oilpressure as my oil pressure gauge in the car

[Billman]

I also have this issue while turning fast to the left causing the oil to go all the way to the right side of the sump (sump wing). I thing the solution would be to build buffles in the sump (as done by many members) or use accusump.

[driftin jo]

@ driftin jo: i get full boost 1.6 bar at 3500 rpm and stays untill 7000 rpm
it's strange actually,i have no peak at all,it begins with 1.6 bar on 3500 rpm en stays
My egt is not higher than 800 degrees measured just behind the turbo
once with boost tuning on vems,i had a peak of 1.9 bar on 3500 rpm en drops to 1.7 bar untill 7000 rpm,i think its possible because i read it somewhere on this forum.
my boostgauge in the car is exactly the same as the boostgauge on vems


@ pasbogdan: fast means When the car pulls up in 1-2-3 gear with full boost on 3500 rpm,then drops my oilpressure from 5bar to 2 bar until I switch from gear
When I'm in 5th gear at 2000rpm and then give full throttle and I get full boost, drops my oil pressure not because my acceleration is then slower than in lower gears


@ ryss:I have measured my oil pressure with a mechanical meter and this gives the same oilpressure as my oil pressure gauge in the car

I'm fairly sure 1.6 bar at 7000rpm is right off the compressor map and blowing very hot air, pointless as it won't make more power, in fact you end up with less power as your intercooler gets heat soaked as it can't cope with the oven temps coming from the turbo.

[Ryss]

Sorry, on reading your posts again I see you did mention you checked with a mechanical gauge.

Last suggestion to get rid of the basics, is to replace the oil filter. Could be a faulty bypass valve, which I had recently. Changed the brand of filter and problem solved.

My problem was a 2bar drop in pressure at 2000rpm. Normally get 4 bar at 2000rpm.

[quattro-nick]

@ billman: i have build buffles in my sump(like the pictures) and the problem stays

@ driftin jo: maybe you have right but after a testdrive my intercooler feels cold on the outside so he does his job very well i think
i have a core about 60cm long,24cm hight and 7cm thick
i know that the air stays very short in the ic for cooling off

@ ryss: This oil filter is new when i rebuild the engine but I'll try another one

thanks for all the reply's guys,i hope this resolved quickly
I will try this week to make a movie so you can see what my problem is

[Audi_CQ]

Have you checked that the rubber piece on the pickup tupe is OK ?

[quattro-nick]

yes,thats also new

[chezz]

Last suggestion to get rid of the basics, is to replace the oil filter. Could be a faulty bypass valve, which I had recently. Changed the brand of filter and problem solved.

My problem was a 2bar drop in pressure at 2000rpm. Normally get 4 bar at 2000rpm.

I was also thinking that this may be a factor...Ive heard of inferior quailty filters causing major problems.

[quattro-nick]

a little update
i replaced the oilfliter but no result
than i put 1l oil extra in sump and make a testdrive,it seams that my oilpressure drops now to 2.5 bar at fast acceleration so a 0.5 bar higher then before
i realy think it's still a oil level problem so what i now going to do is drive my engine warm,let the oil out the sump,remove my valve cover and I pour the warm oil on the cylinder head to see how smooth it runs down to the sump
if thats ok,i have still 2 options:
-i place an accusump
-i place an extra oilsump(can) with 2-3l oil in it that I might can connect through a hose to the oilplug keeping in mind with the hight of the sump.
more oil means also lower oiltemp

[AndyP]

Are you sure the seal on the oil pick-up pipe is not leaking?

I wouldn't go to the expence of fitting an accusump as there is something wrong with your car, I've never heard of this happening before, even on much more powerful cars.

[quattro-nick]

yes,i know,it's a strange problem,i am a mechanic all my life en never had this before
when i rebuild the engine,i put a new rubber seal on the pick-up pipe.because of the problem I have tried many things
one of the last things I have done is that i put another pick-up pipe off an old 2.2 kv engine with a metal suction mouth to the bottom with a plastiek buffle on it and i have still the problem so that rubber seal isn't anymore
You can see through the hole of the side sump that this stands on the same place as the origional one

[quattro-nick]

update from my car
i swapt my 7a sump with my AAN sump
and bild a baffle in it

[quattro-nick]

afterwards i rebuild my cranckcase ventilation
i placed a mann-provent 200 with 25mm (1 inch) tubes
and build an extra big ventilationtube in valvecover