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XJ 4.0L engine whines when cold

Well, don't we all whine just a little bit when we're cold...

Seriously, though, my 87 XJ 4.0L has developed quite an irritating whine that begins about 5 minutes after a cold start-up and remains until shortly after the engine has reached normal operating temperature (I'd estimate the temperature range this occurs is between

155 and 195 degrees).

It is not related to the drivetrain, as it occurs both when the vehicle is moving and when it is sitting still in neutral. I don't notice any significant change in pitch related to engine RPM, although if I do open the throttle slightly while it's whining the pitch will actually /lower/ slightly.

Also, I've noticed lately that my MPG has gone through the floor. Where I used to get 15-16 around town, I now get 13-14.

The sound is loud enough to fill the entire engine compartment, so my attempts to locate it with my ears have been fruitless. Does anybody have any ideas what might be happening here? I've heard guesses ranging from brake booster pump to EGR valve, but those are all just guesses. I'd really appreciate any help.

TIA, Matt

87 XJ Laredo - "Leaks n' Squeaks"
Reply to
Matthew Crouse
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Reply to
FrankW

Matthew Crouse did pass the time by typing:

Your describing a belt driven item.

When it whines, turn the steering wheel to full lock plus a bit. (don't hold it there too long, it's hard on the pump) If you get a real LOUD whine then it might be the bearings on the power steering pump have gone. Next turn on the A/C and listen for any change. If it goes away then it's the A/C clutch or bearing.

As for the rest, those are harder. Usually if the waterpump/fan is going you have a puddle.

Make yourself a mechanics stethoscope. (or buy one)

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- long piece of plastic tube - short piece of copper tube

you slide the plastic over the copper tube. Stick the plastic end up to your ear and touch the suspected componets with the copper end. Just don't get it into the moving parts, that would be bad. :)

With that you can listen to individual things. Like injectors, valves, etc. a very handy tool.

Reply to
DougW

I would be looking hard at the fan clutch. It's a PITA to get a stethascope (or a piece of hose) close enough to it to isolate it but that sounds like something I've heard before - just before the fan outran the rest of the car and had my radiator for lunch.

Reply to
Will Honea

Also check the air intake. The Cherokee's often had a restrictor that would let in less air, so it had less power. If you check the restrictor it may have shifted, causing a strange whine.

Reply to
Mark12211

Hardly a restrictor - the ventura is throat is noticably larger than the throttle body bore. That insert uses the air flow to create a vacuum to purge the charcoal canister.

Reply to
Will Honea

Once again, I'm in the market for a hard top that will fit my 97TJ. I'd prefer something in Oregon or Washington that I can pick up rather than have shipped. If anyone has one, or knows someone who does, please let me know.

Jason

Reply to
Jason Killian

Dude - if you get no response from the group keep doing a search on ebay. I see tops for sale quite often out in your area on there. A little hint do a search for TJ Hardtop & TJ Hard top.

L8r - Jersey

Reply to
Jersey

Mines got a hard-top only too, so I'm either going to install an aftermarket sunroof or save for one of those hard targa-tops. Everyone says that they leak but I think the suffering will be worth it.

Reply to
Trevor

Reply to
L.W.(ßill)

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