1998 Ford Explorer, Engine squeak/chirp from top rear of engine.

Hi all Ihave been chasing this noise for a couple of month now, I found this Topic from 2002 today by Mike Mayer, and his description is Identical to my problem (See below). Has any one else run into this and found a fix, I was going to start a tear down of top end until I saw the info about possible bad injector. does any one know mike and how to get a hold of him to see what he found to be the source of this anoying sqyeak/chirp. I was sure it was a rotational squeak until the reference about injector pulse width.

Issue:

"When the engine is cold, I hear a repeating metallic sqeaking or chirping coming from the area of the rear of the engine. This is the 4.0L V6. After about 5-10 min of driving, it goes away. Sometimes, it's gone even for

several weeks - even when cold.

The chirping goes about 400 - 450 times a minute as the engine is idling at about 800-900 RPM. That tells me the chirping is happening at half crankshaft speed. The spark plugs, fuel injectors, and valves all do their thing at half the speed of crank rotation, so I suppose any are suspect.

Using the ear on the wooden-dowel-against-the-engine trick, I hear nothing inside like a clattering valve or bearing, and no chirping thru the dowel. But can still hear the chirp when just standing there listening.

I listen with the dowel to the injectors and you can clearly hear the rapid tic-tic-tic-tic-tic of the injectors (that's normal). But I don't hear the chirp in the dowel, only from the back of the engine without the dowel, as if it's external to the engine. The ticking of the injectors is in sync to the chirp repeating, so that verified for me that it's at half crank speed. Seems to regular to be a rubbing part on the outside of the engine.

It's not the serpentine belt - we even pulled it off and started the engine for a couple second without the belt - and we still hear the chirping. So that rules out any of the belt-driven accessories and the idler pulley and tensioner, as well ruling out the water pump.

Question is, can a fuel injector squeak? I can't imagine it's the cam or the lifters or the valve guides, as they are all bathed well in oil. Plenty of oil per the dipstick, and plenty of oil pressure per the OP guage. "

Thanks for any clues...

Mike

Reply to
4XMadness
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I had the issue on my 97 OHV 4.0 and it turned out to be the camshaft synchronizer. You can buy a mechanic's stethoscope to help isolate the noise location, I used a piece of garden hose. The synchronizer can be a pain to replace depending on your engine. I had to remove the upper & lower intake manifold to get to it on mine. Look up the thread titled "Chirping 97 explorer " using Google groups.

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Reply to
Captain Coleman

Thanks for your response, I went to the parts store to get a CPS, it was $45.00. It is just the actual sensor that bolts to the top of the shaft. two small bolts and electrical connector. is this what you replaced or did you have to pull the shaft and replace it?

Reply to
4XMadness

I actually had to pull and replace the shaft (aka camshaft synchronizer). The camshaft position sensor can also cause problems, and it's easy to check if you can get to it. Unfortunately, my problem was the synchronizer which required removing the upper and lower intake manifolds plus the fuel rail. Your vehicle may be different as to the exact location of the synchronizer and how easy/difficult it is to get to, mine was a 1997 2wd 4.0 OHV V-6. The synchronizer is a dealer only part and I got them to sell it to me for $115 instead of the $150 they originally quoted me. Did you run the engine without the serpentine belt to make sure it was really coming from the engine?

Reply to
Captain Coleman

It's definitely coming from the back of the engine. The symptoms were identical to your description. I went to Ford and they wanted $390.00 and were giving me a break at $250.00 cause I used to work for them. I then took the ford part number and did a search online and found Dorfman makes a direct replacement, $95.00 including sensor at Auto Value. I didn't believe them so they called Dorfman and confirmed Syncro and sensor assembly. I ordered it right away (back ordered 6 weeks of course). Guess what happened next..... the truck has been squealing for 8 weeks straight every start up. I order the part and it hasn't made a peep for over a week now. I was wondering, when you took out the syncro was there wear from lack of lubrication? I figured the part must have failed due to lack of lube from a plugged oil gallery.

Capta> I actually had to pull and replace the shaft (aka camshaft synchronizer).

Reply to
4XMadness

When I replaced my synchro, the shaft had a fair amount of play when compared to the new one. I could make it squeak when turning it. The synchro itself didn't look worn, I guess the internal bearings (or whatever was in there) had started to wear out. I have no idea what was the cause and I wouldn't know how to tell if it was lack of lubrication.

I took three days to do the job, upper and lower intake and valve covers on my engine had to be removed. I'd recommend using OEM gaskets when you put everything back together. I used the cheapo (cork) valve cover gaskets and my valve covers are now leaking slightly.

Reply to
Captain Coleman

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