OIL PRESSURE HAS BEEN MANUAULLY CHECKED WITH A GAUGE
USED 2 OIL SENDERS BOTH READ CORRECTLY
THE DASH READS CORRECTLY
THE ENGINE IS NOT OVERFILLED
If you've made it this far, thank you for reading
Fresh off a engine swap and new parts, details at bottom.
Currently experiencing unusually warm weather in the northeast winter
Whats in her, Castrol High mileage Synthic/Conventional Blend 10w30 Whats she wearing, K&N high pro filter
The newly installed oil pump is not a high flow/output as far as i can tell
Cold start 80psi
Cold has topped in the 90 low 100s under rpm load
Idles 60psi kinda finicky
any throttle action sends psi shooting up to 80 or so more than likely higher but the XJ oil pump has a pressure bypass at 80psi
Something must be gunked but I cant imagine where to even start looking
I really need the advice of an engine tech on this one
swapped a supposed 110k mile junkyard engine in, its compression was fantastic, dropped the oil pan no gunk/sludge buildups, no metal shavings, journals were unscored, pulled the valve cover everything checked out, nothing loose.
New gaskets (except the head and exhaust manifold)
timing chain
oil pump
water pump
rear main seal
From what I have read, the filler tube is press fitted into the pump....no mention of rtv or anything else. This part I am not sure of and I am just putting it out there to see if anybody else may have thoughts on it. Could the filler pipe connection at the oil pump be sucking air in causing the higher pressure readings?
Given everything you said including checking it with a mechanical gauge my guess is the oil pressure relief valve is stuck. $60 for an oil pump and timing chain/gear is really pushing your luck
BTW: too much oil in the pan will not increase the oil pressure. If it does anything it would lower the pressure if the crank started beating the oil into froth....so you can check that off your list
consequences? If it got up to 80 and was stable there I wouldn't mind but it sounds like it's going higher-a lot higher. I don't know where you are in the NE but as you mentioned its been warm. It's supposed to be 6 this Friday where I am. If the pressure relief valve is not functional a cold soak at 6 and you could start blowing oil filters off.
if,and it's a big if, the relief valve is stuck I'm thinking it's a square peg in a round hole problem, snake oil isn't going to fix that
the filler tube is press fitted into the pump....no mention of rtv or anything else.
luckily I didn’t use any inside the engine, just alittle near the ends of the rear main but alittle can be a lot once it spreads out from the last bearing block smooshing it flat.
Quote:
Originally Posted by exasemech
you are in the NE but as you mentioned its been warm. It's supposed to be 6 this Friday where I am.
im not that far up, currently in PA it’s in the 50s today, I mentioned location because I’m sure on a actually cold day my psi could be much higher
i supposed I could try putting the old oil pump back in
luckily I didn’t use any inside the engine, just alittle near the ends of the rear main but alittle can be a lot once it spreads out from the last bearing block smooshing it flat.
im not that far up, currently in PA it’s in the 50s today, I mentioned location because I’m sure on a actually cold day my psi could be much higher
i supposed I could try putting the old oil pump back in
Yeah, it's 50's here where I am in w Md but supposed to be 6 Fri
in any case:
-From your description of the engine it sounds pretty clean inside so I doubt the problem is sludged up oil passages
-hopefully when you were looking at bearing shells you kept all the oil holes lined up
-If the relief valve plunger in the new pump is somehow messed up you need to worry about it deciding to stick open.
-if you are convinced the pressure readings you are getting from the mechanical gauge are accurate I would be inclined to check out the old pump vs the specs in the shop manual (feeler gauges/plastigauge) and if it's ok, even though it will be a PITA, stick it back in.
again the 80 psi doesn't worry me (my 95 paper shop manual says 75...close enough. The 100+ stuff is getting a little scary because you have no idea what the max might be.
If you do take the replacement pump out it would be interesting to see if the relief plunger moves freely (against the spring tension) all it would take is a small metal chip left over from the high quality Asian manufacturing process to mess things up
