low oil pressure when warm
Discussion
Was hoping an oil change would solve the problem but while it is a bit better its still not right, when the engine is hot and revs are low ( at a junction or in traffic ) I pressure drops dramatically when I pull away again it goes back up, I intend to carry on driving it for the summer I figure if I have to rebuild the engine any way ????? Any thoughts ? I recon its crank bearings / shells?
mikel003003 said:
Was hoping an oil change would solve the problem but while it is a bit better its still not right, when the engine is hot and revs are low ( at a junction or in traffic ) I pressure drops dramatically when I pull away again it goes back up, I intend to carry on driving it for the summer I figure if I have to rebuild the engine any way ????? Any thoughts ? I recon its crank bearings / shells?
Mikel,When you come up ref the body lift my 2 engines are in pieces in the garage so you can see the oil pump, sender and bearing make up etc, I'll also look and see whether your oil pressure is doing what they all do, or is worse. You could also try my working oil pressure sender (only a two minute job to swap them) to see if it is that before you spend money on a new one. This is of course assuming your S1 pressure sender is the same as the one on my S3. The bottom end make up of the 2.8 and 2.9 are the same I believe except for the main crank bearing thrust collars (later have intergrated thrust collars earlier are seperate). Of course the bores/stroke and some dimensions are different but the design is the same.
Mark
Mike I wouldn't be overly worried - if your gauge is telling the truth then clearly there is some wear but provided oil pressure picks up a bit straight after idle there's life in the old dog yet.
What do the tappets sound like? Once pressure really drops off it will be tappetty on the top end due to poor oil circulation.
Can you hear any bearing rumble or clanking at constant revs if you gradually increase rpm?
I had an old 2.3 granny where the gauge hardly registered at all even giving it the beans, sounded like a bag of spanners about 4k revs but never let me down.
14mpg was more of an issue!
What do the tappets sound like? Once pressure really drops off it will be tappetty on the top end due to poor oil circulation.
Can you hear any bearing rumble or clanking at constant revs if you gradually increase rpm?
I had an old 2.3 granny where the gauge hardly registered at all even giving it the beans, sounded like a bag of spanners about 4k revs but never let me down.
14mpg was more of an issue!
Hi Mike, I agree with Chris, you may be worrying about nothing. I have had two engines in this car, both showed about 55-60psi when it was working hard, but dropped below 10psi when hot and idling. That is on a modern semi synthetic but I dont recall any significant pressure difference when I was using a straight mineral oil.
This engine wasnt exactly the height of sophistication when it was new! If I remember rightly it was originally conceived as a fast, long distance van engine. The design goes back to 1968! The 2.8 version we use goes back to 1974. The design was never intended to run at high oil pressures, it simply didnt need it. The specification only gave 38 psi at 2000 revs (whereas the later 2.9 has a number of detailed internal changes and smaller clearances and should give 50-70psi at 2500revs). If you find a 2.8 showing say 70psi at revs and 40psi at idle, there is something wrong with it!
If you are getting over 50psi at high revs, and even as low as 5-10psi at hot idle, and that is CONSISTENT then I wouldnt worry.
If it is inconsistent then the electronic gauge is a likely candidate- get it checked using a fluid gauge.
If you are worried, keep records of the oil pressure, if they show a gradual drop then a rebuild will be necessary at some time.
Incidentally, changing the pump is unlikely to be worth it in my opinion. If my understanding of this engine is correct the pump isnt likely to wear any faster than the bearings etc so if the oil pressure has dropped too low it is almost certain the bearings will need doing.
Incidentally, what pressures are you getting?
This engine wasnt exactly the height of sophistication when it was new! If I remember rightly it was originally conceived as a fast, long distance van engine. The design goes back to 1968! The 2.8 version we use goes back to 1974. The design was never intended to run at high oil pressures, it simply didnt need it. The specification only gave 38 psi at 2000 revs (whereas the later 2.9 has a number of detailed internal changes and smaller clearances and should give 50-70psi at 2500revs). If you find a 2.8 showing say 70psi at revs and 40psi at idle, there is something wrong with it!
If you are getting over 50psi at high revs, and even as low as 5-10psi at hot idle, and that is CONSISTENT then I wouldnt worry.
If it is inconsistent then the electronic gauge is a likely candidate- get it checked using a fluid gauge.
If you are worried, keep records of the oil pressure, if they show a gradual drop then a rebuild will be necessary at some time.
Incidentally, changing the pump is unlikely to be worth it in my opinion. If my understanding of this engine is correct the pump isnt likely to wear any faster than the bearings etc so if the oil pressure has dropped too low it is almost certain the bearings will need doing.
Incidentally, what pressures are you getting?
I have to say I'm not really worried, as said there is life in the old dog yet ,its a bit tappety but not excessivly noisy ,pressure is 50 when driving right across the rev range but zero at idle only when warm, think its just early warning of what's to come, and I just have to decide what route to take, would love a full rebuild with a hotter cam but its expense, might keep my eyes open for an engine on eBay and have a crack at rebuilding this one myself,
This thread has got me worried, my oil pressure drops when idling and raises again when driving but sounds very clattery until the revs are raised and the exhaust takes over. It does seem to have come on since I changed the oil last year and its done so few miles since then im hopeing its just the oil being too thin? (I will look up what oil went in last year as I cant remember off the top of my head). If its not the oil then.............oh dear 
Edited by Terrence79 on Monday 28th May 10:35
Edited by Terrence79 on Monday 28th May 10:36
This thread has got me worried, my oil pressure drops when idling and raises again when driving but sounds very clattery until the revs are raised and the exhaust takes over. It does seem to have come on since I changed the oil last year and its done so few miles since then im hopeing its just the oil being too thin? (I will look up what oil went in last year as I cant remember off the top of my head). If its not the oil then.............oh dear
Edited by Terrence79 on Monday 28th May 10:35
Edited by Terrence79 on Monday 28th May 10:39
I had this problem, and eventually my pressure appeared to disappear.
I changed the sender unit to one of these (there's a thread a few pages back on this) available on fleabay Item number: 370565950654 at a cost of £15.
Solved the problem - the sender units are well known for playing up.
Also running on Valvoline Racing VRI 20W-50 which seems to give excellent oil pressure.
Hope this helps!
I changed the sender unit to one of these (there's a thread a few pages back on this) available on fleabay Item number: 370565950654 at a cost of £15.
Solved the problem - the sender units are well known for playing up.
Also running on Valvoline Racing VRI 20W-50 which seems to give excellent oil pressure.
Hope this helps!
[quote=Terrence79]This thread has got me worried, my oil pressure drops when idling and raises again when driving but sounds very clattery until the revs are raised and the exhaust takes over. It does seem to have come on since I changed the oil last year and its done so few miles since then im hopeing its just the oil being too thin? (I will look up what oil went in last year as I cant remember off the top of my head). If its not the oil then.............oh dear
Would be interested to know what oil your useing, I think the synthetic stuff I had in May of been to blame I only did about 1000 miles last year
Would be interested to know what oil your useing, I think the synthetic stuff I had in May of been to blame I only did about 1000 miles last year
mikel003003 said:
I have to say I'm not really worried, as said there is life in the old dog yet ,its a bit tappety but not excessivly noisy ,pressure is 50 when driving right across the rev range but zero at idle only when warm, think its just early warning of what's to come, and I just have to decide what route to take, would love a full rebuild with a hotter cam but its expense, might keep my eyes open for an engine on eBay and have a crack at rebuilding this one myself,
Mine was the same through the 6 years of ownership. I put it down to 2 things... the engine being a bit loose after 65000 miles and the oil. I used a semi in it generally but after every change it was always better for the first few hundred miles and would then do it again. I had the same problems running on synthetic or semi synthetic oils
I looked up the recommended oil for V6 Granada & Scorpio engines
i.e. Multigrade engine oil viscosity SAE 10W/30 to 20/50.
Change at 6,000 mile intervals or annually so I put in
Valvoline racing 20-50, excellent oil pressure ever since cold & hot
+ I haven't changed the sender unit.
These are old stile engines, most have had a good bit of use & they
weren't designed to run on modern thin oils
I looked up the recommended oil for V6 Granada & Scorpio engines
i.e. Multigrade engine oil viscosity SAE 10W/30 to 20/50.
Change at 6,000 mile intervals or annually so I put in
Valvoline racing 20-50, excellent oil pressure ever since cold & hot
+ I haven't changed the sender unit.
These are old stile engines, most have had a good bit of use & they
weren't designed to run on modern thin oils
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