Oil Pressure Problems

[ajg]

Could someone give me some help regarding oil pressure. I have seen the oil pressure drop to zero on a few occasions when ticking over. This has only happened after the car has warmed up to about 85-90'C and only happened in the first 2 weeks after I bought the car (hot weather at the time). It hasn't happened since (the last 3 weeks) but also hasn't got that hot either, presummably because the weather is a bit cooler?
Oil pressure is normally 28-33 psi when running and 8-12 (a bit higher when cold) on tickover.
With the engine off and the ignition on, the oil pressure gauge needle come off it's rest but still reads well under 0 psi, probably about -10 psi.
I'm hoping this is a faulty sender, any ideas?

[BLUETHUNDER]

It could be a faulty gage,or it could be that the crank is worn. I had a problem exactly like this on a range rover i owned (same engine),it gave a very low oil pressure reading and on further investigation it was found to be that the journals on the crank were worn, i didnt want an expensive bill so i opted for a cheaper job i.e just fit new shells to the crank, this can be done with out removal of the engine in that you can replace these by removing the sump.You can do all of them bar one which sits at the back of the sump which you cant get to.Depending on how hard you drive and the condition of the crank this sort of repair could last for years.Before you attempt any of this do the obvious check and make sure the gage is not at fault,have a compression test done and check that the oil pump is not worn.If you do fit an oil pump make sure its primed before fitment. good luck

>> Edited by BLUETHUNDER on Wednesday 2nd October 06:32

[danny hoffman]

You can change them all while the engine is in a wedge.

I would also checking your cooling system, if the car is getting too hot the oil pressure will drop

Danny

[ocean1]

My car did exactly this shortly after I bought it, showed 0 oil pressure at tick over, about 15 when running. The problem was the oil pressure sender unit, cost about £60 to get it changed. Pressure has been fine since, never less than 15 at tick over when warm, around 40 at speed. TVR power in coventry did the job, they also tested the pressure with a proper gauge before putting the new sender on, the real oil pressure was around 20% higher than showed by my gauge even after new sender.

[Steve _T]

Get this checked out by a specialist unless you really know what you're doing. If the gauge is correct you risk serious engine damage if you continue to run the car. It's more likely to be the sender, but not worth chancing it IMHO.

Hope it all works out,

Steve

[spaceman]

I would also recommend checking the connection of the wire to the pressure sensor. I was getting erratic pressure readings, during a tyre change when the car was up on ramps it was noticed how loose the connection was to the sensor, a 10p spade connector later and all my oil pressure wories have gone away.
Worth a look anyway.

Cheers

Space