XJ40 ( XJ81 ) 1986 - 1994

High oil pressure???

Old 04-30-2019, 07:42 AM
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Default High oil pressure???

Im my old 91 xj40 im starting to have a high oil pressure. It tends to idle at 70punds and jumps right on past the max with a gentle tap on the gas. Ive blown out 2 valve cover gasket because of this. Ive read around and a theres quite a bit on low oil pressure. But I have found nothing on this high oil pressure issue. Has anyone had a similar issue? Ilany input is welcome. Ive only been working on cars for a couple years so im still new to this.

New memeber to the group as well. Little bit about my car. Im the 3rd owner. I was told this car was 90% original the only thing thats been redone is the paint. With just over 89,000 on the odometer this has to be the best car ive ever owned.

any suggestioms on air ride suspension or a conventional conversion for the rear would be appreciated.
Old 04-30-2019, 11:32 AM
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Hi - one thing I can think of regarding the "high" oil pressure reading is that someone (a previous owner) experienced a failing oil pressure sender (very common) and fitted an afternarket unit WITHOUT adding the required resistor.

Without the in-line resistor, the oil pressure gauge would read very high, sometimes 'pinning', when in fact the actual oil pressure is normal.

Is that a possibility?


ps it might be an idea to ask about your suspension in an other thread.
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Old 04-30-2019, 04:40 PM
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I agree, always question the sender. As far as your gasket is concerned I think that if there was actual pressure inside the valve cover area your motor would be sucking oil up through the Evap system and you would have many more problems than just at the gauge. Unfortunately, I have to say maybe your surfaces weren't clean when you replaced the gaskets, or maybe you need to retighten your screws. Sorry, no offense meant. I know those can be a challenge sometimes. I hope it's nothing complicated. Good luck!
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