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Jeep Wrangler Knocking

Q. I have a 1997 Jeep Wrangler SE. It has a 2.5 liter inline 4 cylinder fuel injected engine. It has a 5 speed manual transmission. It does have ABS brakes but does not have A/C. I have a one-inch body lift and 31" tires. Now to my problem; when I have bought this car from my friend it had 74,960 miles on it. When I drove it to my house I noticed oil pressure was fluctuating.

Jeep Wrangler Knocking

Every time I would start the Jeep the oil pressure would be at 0 psi, until I would rev it up to 3,000 rpm and then it would be steady at about 25 or 30 psi. I noticed a sound about a month ago at 79,000 miles and it had a knocking noise to it. I did a redneck trick to where I put a stick on the oil pan to listen if that knocking noise is coming from there and it is.

Now my question is that could I have bad main bearings because of not having any or barely oil pressure? The Jeep was serviced at 73,000 miles and has a new catalytic converter. The guy I brought it from said that the mechanics at Jeep dealership said that they didn't know what was wrong with the oil pressure gauge.

One more question about my Jeep. Every time I start the Jeep and go into first gear and accelerate I hear a squealing noise right under the dash like coming from front axle. When I decelerate the noise stops. I know it's not the engine because I rev it up in neutral and I don't hear it. I only hear it when I'm in actual gear and moving. When the jeep is warmed up, the squealing stops. Do you know what can cause that squeal by any chance?

Thanks,
Chris

A. It is very possible that the rod and main bearings suffered some damage due to lack of proper oil pressure. The little trick you used is a viable test to determine where a noise is coming from and you seem to have narrowed it down. At this point I would drop the oil pan and check a little closer. It may be possible, depending on how long it's been like this, to replace the connecting rod bearings and that will take care of the noise.

I would have to take with a grain of salt your friends statement that the Chrysler technicians didn't know what was wrong with the gauge. The first thing any competent technician would do is take a mechanical oil pressure test and determine if the problem was in the engine itself or in the Oil Pressure Switch (OPS) or the gauge.

The squealing noise is probably a loose or worn fan belt. They would be the first, and most likely, thing to check.

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