Hi,
I have a 1996 Ford Explorer 4.0 XLT 2 WD, and for a couple of weeks now I've had a very loud and intermittent squeak/squeal sound coming from the front of the engine. It basically sounds like belt noise, but it's a "dry" sound. At times, it can be a rotational squeak, and at other times, it can turn into a loud screech/squeal. I thought it was belt noise, so I cleaned the pulleys and belt, but that didn't fix it. Then I noticed that the water pump was making a "meow" sound when I turned it by hand, so I replaced that. Then I noticed that the belt tensioner was broken, and replaced it. Then I cleaned every pulley and groove in the belt system and sanded them clean. I also installed a new belt, and it still does it. I've tried tracking the noise with the stethoscope, but can't isolate it. It's more than a little irritating because I've been trying to fix this for a while, and the sound is loud enough to be heard over the engine noise at freeway speeds. This is a new noise---the vehicle was totally silent until a month ago. Hope for some tips!

 

Question. How about the fan clutch?

 

Well, my dad said that when a fan clutch goes, you can generally see that the grease has been leaking, and this one looks clean as a whistle. (I had to remove it to replace the water pump) I also tried spinning just the fan while holding the water pump pulley, just on a lark. Any other tips for testing it? Thanks!

 

I would suspect alternator bearings or you ac compressor. Does the sound change when you set your heating/cooling switch to off? Just a few thoughts, hope they help.

 

The noise is independent of the a/c system being on or off. I remember talk of the rubber on the a/c clutch for older Tauruses going out, so I thought maybe it was that, but I haven't heard any noises at all coming from the a/c, so I'm skeptical. I did the swap and return test on the alternator and it wasn't the problem. I.E., I bought a new alternator, installed it, and the problem didn't go away! Luckily I was able to return it. I do have a slight bearing problem in my alternator (barely starting, only detectable with the stethoscope), so I plan to replace just the bearing soon. Thanks for the tips!

 

Sounds like the only thing left might be the power steering pump. Are you sure it is coming off the front of the engine?

OK - something else - does a 96 still have a smog pump on it?

 

Sorry I couldn't be more help, good luck.

 

Nope, no smog pump. Looks like I'll be replacing the p/s pump, then. That's OK. I'd rather it was the p/s pump anyway b/c that's 1/2 the cost of an alternator! I'll be trying that next weekend (when I'm at my parents' house and can spill p/s fluid anywhere I want). Wish I could do it now, because I'm starting to get used to the squeaking sound and I don't want that to happen! Don't want to lower my standards! I'll post whether this works or not, and thanks for the input!

 

Well, I hope that is it. I hate recommending something and someone going through the trouble - then it not be it...

I'll keep my fingers crossed for you...

 

Well, when all else fails...try something cheap! Take a bar of dry soap and rub it on all yuour belt surfaces that contact the pulleys. Not a lot, just rub the dry bar down the belt, bumpthe engine over, do the remainder. Its an old trick from the 50's that will stop belt squeal. I know you've done it all the right way...but, heck..its CHEAP!

 

When you replace the tensioner did you see a idler pully somewere on the moter.A pully that the belt just rides on not the tensioner. Looks like it. Also check the belt alignment, if the belt is not in alignment you will have noise sounds like a cat fight.

 

OK, replaced the p/s pump, but unfortunately, it wasn't the problem. Luckily I had just joined a discount program from Amtrak and got a $15 off at Pep Boys coupon, so the pump only cost me $35 out of pocket. After that didn't work, we finally decided to try running the engine w/o the belt. Still had the squeak! So I removed the passenger side rocker arm cover and ran the engine without it. Made a hell of a mess, but that pretty much settled the question. The problem's somewhere in the vavles.<P>
I should mention that 3 months ago, we had to replace the head gaskets, and at that time we did a valve job. The valves seemed to be in like new condition for 114000 mile valves, and I didn't have the time to deal with a machine shop (there's some sort of requirement that machinists have bad personalities in my locale), so we did the job ourselves. Now we're thinking that maybe there's some varnish built up on the valve guides, and since we didn't clean the heads as well as a machine shop could have, and since we couldn't put the valves in in EXACTLY the same positions (same cylinders, but it's round), hopefully it's rubbing and making noise.<p>
That, or we have a bent valve. For now, we're taking the fingers-crossed steps. CD2 in the oil and Mavel Mystery Oil in the gas. Hopefully, that will dissolve the deposits if they're there. Otherwise, I'm looking at another head job. Any suggestions for solvents/additives would be appreciated!<p>
Also, I read about an upper cylinder lubricator on the side of the Marvel Mystery Oil can that's supposed to help out with the lubrication process. Anyone know about this? It's supposed to deliver Marvel Mystery Oil I noticed that the lubrication system on the 4.0 isn't as effective as the old style (where the hollow pushrods pump the oil to the rocker arms).

 

I do not know that other lubs. you can use. Sound like to get it right, your going to have to get back into it again. I would look at set of junk yard heads that you can have done right, just so the truck is not down long. Also whats the oil psi?

 

Franklin411:

I also have a 96 Explorer 4.0 and have the exact same symptoms which you mentioned above.

Please let me know if in fact it was valve related.

How were you able to fix it?

My car runs great otherwise.