lost oil pressure after oil change

[mcgill]

brief history,have a 1970 v8 rover lump"42,000" miles...i change the oil every,250 miles..(i dont do alot of miles)
the reason for the constant change is due to a internal fuel pump leak,filling the sump with fuel.after this happened,my once silent engine,got itself a lone tap.
since then ive been changing the oil in hope it may shift the bit of cr*p wherever it is,im assuming its the hole in tappet..
my oil pressure is usually halfway warm tickover,going to 3/4 on acceleration.
my new penrite oil hpr30,turned up saturday,so along with new filter,it all got changed,and primed
HOWEVER,the hpr 30 i ordered turn out to be hpr40(on the can),and on start up my tap was even worse,even when warm,my oil pressure ent to 3/4 on tick over..
not happy with this,i drained this morning,a nd replaced,with 20/50,along with another filter.on start up i noticed my oil light went out,but had tincy wincy pressure on gauge,(it moved about 2mm).i checked gauge to earth and that worked,so i assume.its the gauge transmitter...went to get another,and found they were £60 odd quid deliveered.ouch!!
the car i have is a p5 rover,and i know they shared parts with the early rangies,and mgbv8s...ive looked through my factory parts catalogue,and cannot find transmitter/sender so have noithing to cross reference with...
is the anyway i can test the transmitter?
what else couldve gone wrong...i darent start it now

[DaveEFI]

brief history,have a 1970 v8 rover lump"42,000" miles...i change the oil every,250 miles..(i dont do alot of miles)
the reason for the constant change is due to a internal fuel pump leak,filling the sump with fuel.after this happened,my once silent engine,got itself a lone tap.
since then ive been changing the oil in hope it may shift the bit of cr*p wherever it is,im assuming its the hole in tappet..
my oil pressure is usually halfway warm tickover,going to 3/4 on acceleration.
my new penrite oil hpr30,turned up saturday,so along with new filter,it all got changed,and primed
HOWEVER,the hpr 30 i ordered turn out to be hpr40(on the can),and on start up my tap was even worse,even when warm,my oil pressure ent to 3/4 on tick over..
not happy with this,i drained this morning,a nd replaced,with 20/50,along with another filter.on start up i noticed my oil light went out,but had tincy wincy pressure on gauge,(it moved about 2mm).i checked gauge to earth and that worked,so i assume.its the gauge transmitter...went to get another,and found they were £60 odd quid deliveered.ouch!!
the car i have is a p5 rover,and i know they shared parts with the early rangies,and mgbv8s...ive looked through my factory parts catalogue,and cannot find transmitter/sender so have noithing to cross reference with...
is the anyway i can test the transmitter?
what else couldve gone wrong...i darent start it now

If the oil pressure warning light acts as normal, the chances are it's a gauge or sender fault. I don't think any other vehicle used the P5 oil gauge - but the guys to ask would be on the P5 forum.

[topcatcustom]

Where abouts in essex are you?

Also on a seperate note- changing your oil often won't make any difference to shifting any crud stuck in a lifter, old or new oil will push it out the same and it will get caught in the filter just the same! (that is if the problem is actually some rubbish in there- unlikely I'd have thought??)

[mcgill]

hi all ,thanks for ya posts.
bit of a update,good and bad news im gutted to say.
im over in maldon
The sender can be got hold of,£200 if you want an original part,but britpart do one for £30,not alike visually but same part number "555947".WARNING they only work on so i was told 68 /72.Later engines like the sd1 etc dont really like em...so early range rover p6 mgbv8 p5.
problem not solved though.is there a valve or spring in the filter housing,that could cause same problem??
all the best

[topcatcustom]

Maldon! I'm only up the road in Tiptree (during the day), and I have a brand new mechanical oil pressure gauge which you could screw in to find out whether your gauge is working or not.

[kiwicar]

Yes there is a bypass relief valve in the body of the pump it can stick open, can sometimes be unstuck by belting the pump with a bit of wood.
Best regards
Mike

[unstable load]

Like kiwi says, get hold of a broomstick or thicker piece of wood, place it against the pump body and give it a belt with a buggering stick.
May work better if it's warmed up, but if you don't want to run the motor it should still be OK. If you oil light is going out, the pressure should be OK to run the motor to warm it up, just keep a beady eye on the idiot light.