Low TJ oil pressure = new oil pump?

Sounds pretty cut and dried, if it's not the Oil pump then you've got something very strange going on like a cam bearing with a crack that's letting oil pulse out or something like that...

On the other hand if it is the pump and you aren't hearing lifter noise yet then it's probably not too late for your bearings... lifters deflate and start clattering below about 9 or 10 PSI.

Bill Hughes

Please re-read my post... the oil pressure varies even when I replace the electrical measurement of oil pressure with a mechanical oil pressure gauge.

The mechanical oil pressure gauge is attached to a tube which screws into the block... oil actually goes from the engine up the tube and applies direct pressre to a diaphragm/spring coil loaded needle... this is the most accurate albeit old-fashion way of measurine engine oil pressure.

That's why I asked if it could be more than an oil pump problem.

Ralph

God exists, or God does not exist, or I am God and I am dreaming all this.

If these oil pressure readings are real, then your symptoms point to worn out bearings. The pump itself is not likely to wear out, because it is the best lubricated part in the engine. Other possibilities are a blockage on the pump intake, perhaps from sludge, or idle speed too low. Clean the idle air control valve to address that problem. It is odd to see a vehicle of this mileage with this low oil pressure, even at idle, especially if it has been maintained well.

We had a woman in the commune who drove probably sixty miles, to find someone who could tell her what the little blue dash light on her Karmann Ghia was all about. :o(

Earle

Paraphasing FSM: Low oil level Faulty sender Worn bearings Clogged filter Thin/contaminated oil (water/coolent) Oil pump relief valve stuck Suction tube loose or damaged Oil pump cover warped/damaged

"L.W.(Bill) Hughes III" wrote in news: snipped-for-privacy@cox.net:

Earl Horton;

Which bearimgs might be worn out?... in the pump?... camshaft?... ?

Ralph

God exists, or God does not exist, or I am God and I am dreaming all this.

Bill Hughes

Thanks for the schematic... that helps my understanding of the TJ's pump operation... seems typical for engines.

Over the past 56 years I've had many cars... starting with a 40 Hudson,

If the camshaft turns a "jackshaft" which drives the pump, can worn bearings be the culprit? The pressure does not always drop when the engine is at idle... I'd guess only about a third of the times when the engine speed drops to idle... most of the time it drops to about 20-25.

It NEVER drops at road speeds... city or highway.

Ralph

God exists, or God does not exist, or I am God and I am dreaming all this.

My wife's '97 with a 2.5 has EXACTLY the same problem.

It would drop so low that at idle, the check gauges lights and all would come on.

I currently use straight 40wt oil in it to keep the pressure up. Don't know what I'll do when winter comes.

It started around 62,000 miles. It now has around 68,000 on it.

No other symptoms or noises.

It would really shock me if cam or crank bearings were worn out at this low mileage, but that is where the pressure is "made".

Spdloader

Alas, crankshaft bearings.

I would check things out in this order:

Change oil & filter (would cure any thin oil or bad filter issue) Replace pump (would cure pick-up & pump issue)

snipped-for-privacy@webtv.net (Ralph DL) wrote in news:24405-44D62422-22@storefull-

The pressure is "made" by the pump. Bearings is where it could be "lost".

That's what I was saying, note the quotes around the word "made".

Spdloader

Oh, I see. The quotes mean you were wrong on purpose. I guess I've just never seen them used that way before...

...wrong on purpose, yep, that's a better way of putting it!

Spdloader