I have a bit of a low oil pressure problem with my redtop.
Starting from cold (10:40 GTX semi synthetic) the engine takes quite a bit to build up oil pressure - the oil light stays on and the pressure guage
doesn't move for over a minute - in fact, today it only started to show a pressure after 90 secs when I gently raised the revs above tickover.
Once it starts to rise, it goes up smartly to 75 and stays there until the engine gets warmer and the oil thins. Then it slowly drops down until, at
normal operating temperature, it shows 10 to 15 psi (on tickover). Thereafter, the pressure picks up to 50 / 60 psi at anything above tickover
revs.
Starting the engine (warm) after leaving it for 15 - 20 mins to drain down it takes even longer to show pressure.
I don't believe it is a normal low pressure engine fault (ie valve guides, piston rings, worn bearings etc) but rather one of supply ie the pump
etc.
Any ideas and / or suggestions would be gratefully received. Please note I have replaced the over - pressure relief valve with SBDs nylon one.
[Edited on 25/8/11 by stevegough]
if you're confident its not bearings(as its showing all the signs of just being on the way out) maybe you'll be best trying another pump?
When my mains went it was showing the same thing. Have you checked the oil pressure gauge is working correctly?
Check the oil pressure release valve - little nylon piece on the side of the pump. These have a tendency to become sticky and not move freely. Clean
the valve and chamber, check the spring, or I believe the valve can be replaced with an aftermarket part from one of the tuning companies. Else next
step, as mentioned above, is to consider a new pump.
My 2p added!
*Edited to say*
just seen your note on the SBD relief valve, should've read more carefully!
[Edited on 25/8/11 by Charlie_Zetec]
Did you need to use any washers to set the SBD nylon releif valve up ? (as in the instructions)
Would be worth rigging up a mechanical oil pressure gauge to rule out any sender/gauge issues
Also what does the top end sound like when its low on pressure, is it tapping like a good un or is it ok ?
[Edited on 25/8/11 by perksy]
Thanks for your replies, guys.
I used one washer ( as I recall ) to set up the relief valve, and the top end sounds 'ok' with no oil pressure, but the engine definitely
quietens down as soon as the pressure lifts (not surprisingly as the tappets are hydraulic?) but I wouldn't say it is unduly tapping.
If it is the main bearings, why would that cause the pump to be so slow to pick up pressure?
My thoughts were it might have been the oil pick - up pipe come loose, and instead of sucking up oil, the suction was being hampered by the air
inleak. However, I removed the sump yesterday, and it was perfectly tight. I removed it and replaced the 'O' ring, all with no noticeable
effect.
Later today, I will try fitting another washer in the relief valve tube, but as that only helps to increase the blow-off pressure, I don't think
it will help with the priming (or lack of) situation.
The next action is to strip the oil pump and see if its lost any teeth?
If I replace the pump, I seem to remember reading somewhere that there are some poor pattern parts on the market which are absolutely useless - anyone
know?
When my mains went it was the slight lack of resistance to flow at idle rpm(crank driven pump) causing poor pressure. When revving and oil flow was
greater I was still getting the correct pressure/resistance to flow.
When the engine was warm it would take longer to get pressure as the oil was thinner. I ended up within 5 miles having an engine that wouldn't
give any oil pressure under 1500rpm but the correct 50+psi at 5000rpm
I hope its not the above but it seems very similar to what I had happen.
quote:
Originally posted by franky
When my mains went it was the slight lack of resistance to flow at idle rpm(crank driven pump) causing poor pressure. When revving and oil flow was greater I was still getting the correct pressure/resistance to flow.
When the engine was warm it would take longer to get pressure as the oil was thinner. I ended up within 5 miles having an engine that wouldn't give any oil pressure under 1500rpm but the correct 50+psi at 5000rpm
I hope its not the above but it seems very similar to what I had happen.
Out of my 6 mains these are an example of how little wear was needed....
pick up pipe blocked??
sump pushed against strainer?
O ring on pipe mising or failed.
Pin hole in pipe from moifying/welding
quote:
Originally posted by omega 24 v6
pick up pipe blocked??
sump pushed against strainer?
O ring on pipe mising or failed.
Pin hole in pipe from moifying/welding
Did the sump come from QED aswell as the pick up pipe ?
Have heard a few folks who have had issues with the pick up pipe head touching on the bottom of the sump causing oil pressure issues
Might just be worth dropping the sump and checking this
Also whilst its off i'd be tempted to drop the second to last main bearing cap off (away from the oil pump) and check the condition of the
bearing
quote:
Originally posted by perksy
Did the sump come from QED aswell as the pick up pipe ?
Have heard a few folks who have had issues with the pick up pipe head touching on the bottom of the sump causing oil pressure issues
Might just be worth dropping the sump and checking this
Also whilst its off i'd be tempted to drop the second to last main bearing cap off (away from the oil pump) and check the condition of the bearing
Good luck, my fingers are crossed it something simple(cheap!).
It does sound like an air leak on the pickup, needing a few revs in order to overcome it at which point its primed enough to continue...
This problem is baffling me......
I took the car to work 3 days ago, when I started it to come home, it took about 7 minutes to show any oil pressure - in fact, I had started to drive
it home at just above tickover - got about 1/4 of a mile, the oil pressure suddenly rose to 70 or so psi where it stayed until it warmed up
properly.....when sitting at lights at tickover it drops to about 10 psi.
Well, today, went out with the idea of doing some investigating and stripping the oil pump, just thought I'd try starting it again.....started,
tickover only - oil pressure came straight up and within 3 seconds was showing 75 psi. So - bearing in mind the last time it ran was 3 days ago, and
starting it then took 7 minutes to get any oil pressure........WTF ??
Rusty nuts has suggested changing the Fram oil filter for an OEM one - might be an issue with an integral non-return valve.
So, what to do? - this is such a weird problem.
New engine?
New oil pump?
New oil?
New Main bearings?
New Car?
Change to a Zetec?
New Brain?????
I reckon you have bottom end bearing issues to be honest.
I had the same problem at the beginning of the year and was looking at all the issues you have listed above(oil pick up too close etc) and turned out
to be the bearings in the end.
For the sake of dropping the sump and having a quick look, its a no brainer.
Oil pump would be next stop but doubtful.
I was led down the filter route too but made no difference(still using the Fram one now).
Is it a mechanical or electronic gauge?
Ok, sump off, no 2 main bearing cap off, then I'll let yous all know what I find.
Pics now added - see new thread......linky
Quick replies appreciated..... don't want to leave the bearing cap off for too long....