Oil pressure - should I be worried?

rodent · Postby **rodent** » Fri Jul 28, 2006 6:17 am

Here we go with another OPG question :oops:

At idle:

@4000rpm it's barely above 3.
Oil level is full, but I still haven't changed the oil yet (~7k since last service).

And despite changing the CAS seal, there is still a small oil leak which I think may now be head gasket related

Could the oil pump also be on the way out?

jonno.

StanTheMan · Postby **StanTheMan** » Fri Jul 28, 2006 8:37 am

gawd what oil & oil grade are you using?

Garry · Postby **Garry** » Fri Jul 28, 2006 10:15 am

Clean the contacts at the oil presure sender on the block and the ones at the gauge behind the dash.

jules · Postby **jules** » Fri Jul 28, 2006 10:57 am

My oil pressure used drop a \"little\" when the oil got on. I change oil every 5000kms or 3 months. I haven't really noticed of late. The readings you are getting would concern me though. I wouldn't be concerned about engine damage per se, more about what may be causing the symptom.
I'd try Garry's idea first, then do a bit of an engine clean and new filter with quality oil.
If it is still low then you'll need to dig deeper. Remember the difference between \"full\" and \"low\" on the dipstick is minimal.

I don't believe any oil leak could affect pressure to the level I'm seeing on your gauge. The guage itself may be stuffed as well. Wouldn't that be funny after doing all the other stuff.

Jules

sabretooth · Postby **sabretooth** » Fri Jul 28, 2006 12:43 pm

If you had a leak which would cause pressure drops then you'd have a pretty serious issue to the point where the engine wouldn't survive for more than a few miinutes. This would be after it's dumped oil everywhere.

An oil leak isn't going to be a headgasket problem. Possible leak points include:

oil filter
oil pressure sender
CAS O-ring (which you've changed)
cam cover gasket
front oil seal
rear main seal
Camshaft oil seals
sump sealing

The best way to find out where it's from is to get on your back and go underneath and start looking. If the oil is coming from a small hole behind where the gearbox attaches to the engine, then it's a rear main seal leak. If it's from the front of the motor. it's the camshaft seals, sump or front crank oil seal. driver's side of the engine means the oil filter, oil pressure sender, cam cover or sump. Passenger side means CAS O-ring, sump, or cam cover

I think your oil pump is fine. You probably may just need to change the oil. Subtle variations in oil pressure aren't worth worrying about.

JSE · Postby **JSE** » Fri Jul 28, 2006 1:36 pm

I had an oil leak and replaced every single seal that you listed there Sabretooth plus changed my oil filter and still I had a mad leak...mine was a mystery and when the engine was taken out from the rocker cover down was just black covered in oil :lol:

rodent · Postby **rodent** » Fri Jul 28, 2006 8:17 pm

Well I drove the car again today and the oil pressure seemed to be normal this time around - a hair under 2 at idle and much closer to 4 @ 4000. Guess I'll just chalk this one up to some freak gauge/electrical problem

About the oil leak:
I've traced the leak back to around where the head bolts on - even took the extractor heat shield off to see a little bit of oil in that area. It's mostly towards the back of the engine though which is why we thought it could be the CAS seal. The engine from the head up is totally clean

I'm only losing a few drops here and there so it's not really concerning me right now.

I reckon I'll just change the oil and see what happens from there. Thanks for all the input guys, will keep youse updated

jonno.

muzza2 · Postby **muzza2** » Fri Jul 28, 2006 11:43 pm

i've noticed mine sits higher when the oil needs changing.
so clean ur oil out (if u havent done so for awhile) then see how she goes
mine normally goes down after a good change =)

glen73 · Postby **glen73** » Sat Jul 29, 2006 7:45 am

muzza2 wrote:i've noticed mine sits higher when the oil needs changing.
so clean ur oil out (if u havent done so for awhile) then see how she goes
mine normally goes down after a good change =)

i get better oil pressure when i do an oil change.
i have noticed since the introduction have my turbo the sensor has been out. maybe because the oil is now running through the turbo. should i compensate for this?

muzza2 · Postby **muzza2** » Sat Jul 29, 2006 9:19 am

i think... dont quote me on this, but i think
when u have a turbo the oil pressure is higher then standard in the first place...

glen73 · Postby **glen73** » Sat Jul 29, 2006 9:28 am

muzza2 wrote:i think... dont quote me on this, but i think
when u have a turbo the oil pressure is higher then standard in the first place...

somthing you have to remember is the oil passing through oil outlet hose, then the housing, through the return line then back into the sump. i thought it might be because the area volume has been enlarged then there wont be as much oil pressure. hence do i need to compenstae for this extra volume in area to bring up the oil pressure. my return line is longer then the normal so im thinking maybe another 100-150ml in oil.

rodent · Postby **rodent** » Sat Jul 29, 2006 10:05 pm

phatMX wrote:When i change mine it goes up. My pressure is a tad over 4 when i'm at 2000rpm Is that normal?

Is that with the engine warmed up?
IIRC normal operating conditions is 3-4 @ 4000rpm.

However if you're using dodgy or really sludgy thick oil (or it's just old) you'd get higher pressures. Another potential cause is overfilling.

Hey guys I seem to be getting the low pressures again this afternoon (nice warm sunny day just like last time, driving with the roof down). Still within guidelines @4000rpm but idle is way waaaay below 2, and engine feels pretty lumpy too so I'm not sure it's the gauge

My mech originally filled it with some Valvoline synthetic stuff, and I topped it up with Shell Helix 15w40 after discovering the leak. Think I might have overdone it too, since it now covers the 'F' mark on the dipstick :oops:

- that should've made the pressure go up if anything?

Any other ideas, or think I should just take it to Mania..?

jonno.

Moggy · Postby **Moggy** » Mon Jul 31, 2006 8:49 am

I've noticed that if my engines are low on oil then I get a very noticable ticking noise from the cams under-oiling.

I personally wouldn't think it's a leak - it would take a pretty large (and I mean oil everywhere) leak to drop your oil pressure noticably. It could be an inefficient (or on the way out) pump or more likely just very thin oil - this can be caused by the oil getting hot so if it is a hot day and your engine is not cooling efficiently then that would cause a noticable drop in pressure.

My advice - don't worry about it...