Gte low oil pressure on idle

[NeilBoylan]

Hi guys having an issue with the manta had the head rebuilt new everything oil light is on I have changed the oil pump switch also had different timing chain cover I am going to do a compression test tomorrow to see what is going on in the bottom end what figure in each cylinder should I have thanks for your help guys 

[cam.in.head]

hi . a compression test wont tell you anything about oil pressure only cylinder / piston pressures !

if the oil pressure was ok before head job then i would suspect that work first . assuming everything was reassembled correctly .

firstly ...is it low oil pressure at idle anx ok above of low full stop ?

[1200bandit]

Have got a 2.0 GTE 1988 82,200 miles,oil pressure at 800 RPM is around 1.5 bar,when cold at 2000 RPM oli pressure 3.0 bar 

when driving about 4.0 bar 

[cam.in.head]

sounds about right 

in theory no lower than 0.5 bar at idle and no higher than 5 at high revs when cold ( atound 3-4.5 warm at higher revs .

all dependant on oil grade . i use 15w/40 or 20w/50( althou they can use thinner !)

 

conpressions are a bit irrelevent realy in this case but dependabt on engine condition ( and make/age/accuracy of tester) my 2litre S gives around 170 psi snd my 2.2's around 210-220 psi .

just in case you were curious snyway

[NeilBoylan]

When the car is warm the red light comes on I am doing compression test to see if I am taking out the engine to get the bottom end rebuilt Andrew abbot  helped out with the rebuild so I know it’s been put  together properly I think the issue is the timing chain cover I have another one to replace it I have changed my oil from classic 20/50 to valvoline racing 20/50 as advised by opie oils the timing cover has been nothing but issues there was no thread for oil filter to screw on to thanks for your help 

[cam.in.head]

i assume you mean that the oil light comes on when hot only at idle and increases ok when revs are higher .this would indicate general wear to either oil pump casing, gears or engine bearings . it could also be wear on the oil pump cover or leakage of the pressure relief valve on it . or  fitment of a gasket to a cover that doesnt require one ( or too thick)

was it ok before head was changed / repaired ?  if so have one of the gallery plugs come out between the rocker studs . rare but can happen !

[Jessopia74]

3 hours ago, cam.in.head said:

i assume you mean that the oil light comes on when hot only at idle and increases ok when revs are higher .this would indicate general wear to either oil pump casing, gears or engine bearings . it could also be wear on the oil pump cover or leakage of the pressure relief valve on it . or  fitment of a gasket to a cover that doesnt require one ( or too thick)

was it ok before head was changed / repaired ?  if so have one of the gallery plugs come out between the rocker studs . rare but can happen !

You’re probably correct on this one, the different timing cover is a red flag too. Seen it where the front cover to oil gallery leaks into the timing chain area losing oil pressure.

[cam.in.head]

ive also seen it where a late timing case is fitted and an early oil pump cover resulting in NO pressure releif valve !

or an early case and a later cover resulting in 2 releif valves ( althou this shouldnt cause an issue but its 2 places for bleed through!)

[Paul Barrett]

With 20/50 pressure should be good. 
losing it somewhere for sure. Go with your gut here I reckon with timing cover. I’ve a few but a lot are corroded badly from poor coolant Maintenance and oil pump housings scoured badly. 
 

not teaching to suck eggs Neil but what were the oil pump gears like and the cover plate?

[cam.in.head]

yeah 20/50 (or even a 40 grade should be perfect) cant comment on anything thinner as i never use any .

as originally asked thou . was the oil pressure ok before you did the head ?

and if the timing case has already been changed . what was the reason ?

[rutts]

On 20/11/2024 at 20:45, Paul Barrett said:

With 20/50 pressure should be good. 
losing it somewhere for sure. Go with your gut here I reckon with timing cover. I’ve a few but a lot are corroded badly from poor coolant Maintenance and oil pump housings scoured badly. 
 

not teaching to suck eggs Neil but what were the oil pump gears like and the cover plate?

Oil pump gear Cover plate is brand new one that you use gasket with. 

[Paul Barrett]

1 hour ago, rutts said:

Oil pump gear Cover plate is brand new one that you use gasket with. 

He hasn’t said if he’s replaced them. 

[Jessopia74]

1 hour ago, Paul Barrett said:

He hasn’t said if he’s replaced them. 

Different timing chain cover, could indicate wrong cover or even wrong gasket used, or even just a sticky relief piston. 

[Paul Barrett]

Yes there are several variations, pretty much have them all I think. 

[cam.in.head]

11 hours ago, rutts said:

Oil pump gear Cover plate is brand new one that you use gasket with. 

all early covers ( solid plate with no valve) use a gasket.

then they went to later covers with valve which used a gasket ,even later is same cover but no gasket ( timing case is different)

we need to see what op says regarding .....was oil pressure ok before and why did original cover get changed ?

ah just seen it. op says thread was knackered in casing for oil filter to screw onto ( never seen that happen before )

or external thread was for some reason ,? and he didnt just replace that little piece ?

Edited 2 hours ago by cam.in.head