12 replies to this topic

[shep_cobain]

I have just been informed that high oil pressure can cause high temps.

The cars oil pressure according to the gauge is over 100psi at all times, idling, driving etc etc.

Ive also noticed the voltage is 14+

Are these readings normal and how would i go about lowering the oil pressure?

[Ferretboy221]

I have just been informed that high oil pressure can cause high temps.

The cars oil pressure according to the gauge is over 100psi at all times, idling, driving etc etc.

Ive also noticed the voltage is 14+

Are these readings normal and how would i go about lowering the oil pressure?

very likely that you oil pressure relief valve has jammed closed..... its a bullet shaped piston in the front of the block that controls the pressure at which oil is supplied to the main galleries. they have a tendency to jam however if small amounts of muck/metal get in the sleeve.

this causes a very high oil pressure as the engine receives the maximum pressure the pump can put out.
it need addressing immediately...

the relief housing is just to the left of the oil pressure switch output on the engine block, it requires a 24 mm or 1" socket/spanner to undo. bear in mind as you remove it that the cap is under tension from the relief spring and the whole lot will try and jump out. then you can use a magnetic tool to withdraw the plunger , i would expect given your problem that the plunger will be stuck at the furthest point in the chamber.

Just did this procedure on a friends engine that had a diff bearing explode, his was stuck at the far end and in the end we had to use a internal threading tap to latch on and remove the plunger as the magnet was not strong enough.

Edited by Ferretboy221, 23 April 2011 - 01:37 PM.

[bmcecosse]

I would have to suspect the oil gauge if the pressure is showing 100 psi at ALL times - even hot idling ?? Is it an electric oil gauge ? Check the pressure with a normal capillary gauge. If the pressure really IS that high - there must be a problem with the relief valve. Take it out and clean it - checking it's not sticking. The 14 volts shown is at the top end of an acceptable reading.... Again - check it with a good multimeter.
Some electric gauges are intended to be run from the 10 volt stabilised voltage regulator on the back of the speedo.......have you checked this ?

Edited by bmcecosse, 23 April 2011 - 01:32 PM.

[Joe555]

I posted the same high oil pressure problem about a week ago, the problem was that I had fitted a ball to replace the plunger reliefe valve. replaced the pluger, promlem solved.

Joe

[Kerrin]

Can I suggest that you check the pressure with another gauge before you do anything else.

I had the same gauges fitted and they were not very accurate.

If the pressure really is that high, as others have said it will be the oil pressure valve requiring modification to the ball/cup and spring combination. The spring may need trimming down.

[Rented]

Check you PCV system as it maybe blocked , also the installation of the incorrect oil filter can cause high oil pressure ( incase you have changed it recently ? ) or even a blocked filter and a dicky pressure relief valve could cause this problem too . Worth a wirl on those 2 if all else fails .

[shep_cobain]

Check you PCV system as it maybe blocked , also the installation of the incorrect oil filter can cause high oil pressure ( incase you have changed it recently ? ) or even a blocked filter and a dicky pressure relief valve could cause this problem too . Worth a wirl on those 2 if all else fails .

Well its had a new head rebuild and the engine has just gone back in. So new filter, new water pump, new radiator. I started it for first time other day and temp is just going above 100c and the oil pressure is passed 100psi as you can see in the picture. The thermostat works fine and is a 74c one. I can't think what the problem is?

[shep_cobain]

Would high oil pressure cause high water temps?

[shep_cobain]

Would high oil pressure cause high water temps?

Bump

[Shifty]

Are the guages electrical or mechanical?

[Gulfclubby]

Are the guages electrical or mechanical?

Good question, as when voltage on the gauges is too high, they will all read too high, too. This could just be the case. Are they fed through a voltage regulator or do they have one in each?

[mikey72]

I'd look at the gauges, the temp gauge is in the red too.

[Kerrin]

Without abusing the swear filter, check the gauges first, I bought a full set of them and they are pants! they were in the car for less than a week and are now sat in the garage pending the next big garage chuck out.

Get some proper gauges on it to check before you do too much messing.

My oil pressure never went below 25psi even with the engine off. They are either very rubbish or don't suit a mini's voltage system or voltage regulator, even fitting a voltage regulator to the feed made no difference to the reading.