Nasty Engine Chirp (92 Explorer)

[billymcgates]

Hi there,
I've done some digging through the forums and Google, but I think I've found myself more confused than enlightened. Here's my situation, I hope someone can help.

I have one of those odd models where Ford put a '92 engine in a '93 body (learned about this when I kept buying the wrong parts). Looking into that reveals my trusty Explorer to have been made at the start of January 1993, so I think that explains that...

Anyway, last year I developed a small chirping sound in the engine that was intermittent and at the time not a concern. As of the last two months, the sound has gotten unbearable. At first I thought it was a bad belt, so I replaced it with no success. I then replaced the tensioner pully, no luck. The entire tensioner assembly, no luck. I took it to the mechanic, who insisted that it was the tensioner, and two days, a lot of arguing, and a refund later, I proved that it wasn't the tensioner. They then proceeded to tell me there was a chance that I had a cracked fly wheel creating the chirp, and I was looking at a cool $1000 for the repair. Since it's a 4x4, they couldn't just look at see if that was the case, they'd have to charge me by the hour to get the transmission, drive train, etc out of the way to verify. I checked my Explorer out and hit the forums.

The chirp appears to be coming from the rear of the engine, and persists with the belts on or off. It doesn't seem to matter what temperature, and sometimes it will fade while driving, while other times it'll persist no matter what. I saw quite a few posts about the camshaft position sensor being the possible cause, but when trying to find the part it looks like that isn't in my particular model? That's where I start to get confused. If you can shed any light on this, I would appreciate it a lot. I don't want to get rid of the car for something that might be a simple fix (the body is cherry and it runs like a champ otherwise), but I'm not about to drop $1000 on one that isn't worth much more than that.

Thanks in advance for your help!

 

[ragajungle]

years ago I engaged the starter on my mom's aerostar while it was running by accident and it cracked the flywheel causing a squeaking sound when it ran. The faster you reved or drove the worse the squeaking... Sorry but the mech might be right. Unfortunately squeaks are demons and chasing them is hell...

 

[rhauf]

my damn cat just erased everything i wrote. so i'm writing again.

ok, have you tried running it (for a moment) with the belt removed? this would eliminate the possibility of the squeak being accessory related.

another thought is the cam sensor, if it has one.. i'm not sure if a '92/93 has a cam sensor, but i had a nasty squeak on a windstar a while back which turned out to be a cam sensor (i know, different engine) its just a thought..

 

[xSnoWx]

although product wise completely unrelated, honda v6's got a chip that came from the timing cover which turned out to be the hydraulic tensioner causing the squeak... but I think that yours sounds more like a cracked flywheel... seen more blown clutches than cracked wheels tho...

 

[rhauf]

although product wise completely unrelated, honda v6's got a chip that came from the timing cover which turned out to be the hydraulic tensioner causing the squeak... but I think that yours sounds more like a cracked flywheel... seen more blown clutches than cracked wheels tho...

His 4.0 OHV doesn't have timing chain a tensioner. it's not over head cam.

if it does turn out to be a cracked flex plate, at least it's not an expensive fix. just one that takes all day.

 

[jd4242]

His 4.0 OHV doesn't have timing chain a tensioner. it's not over head cam.

:scratch::scratch: umm the ohv HAS a timing chain tensioner.does it get louder with more rpms?is coming from the bottom of the motor or top?

 

[billymcgates]

Ok, sorry it took me a while to get back to you guys. I went out of town for a little while, and the starter went out on me last night. Got that replaced, and while I was down there I ran the recommended tests.

With the starter out I was able to get at the flex plate and stick a flex camera in it. It doesn't appear to be cracked, but is definitely very worn. After putting the starter back on, I ran it without the belt to rule out the accessories. The chirp was still there, so I crawled under it with the motor running, and got directly beneath where the flex plate is. Sure enough that's where the noise was loudest.

The flex plate was only $57, and I returned my old water pump for a core credit toward it as well. Since I don't really have the time or the means to take out the transmission, move the drive shaft, and all the other parts that are standing between it and me, I'm calling shops to see who can take install the part for me at the lowest rate. Wish me luck!

 

[billymcgates]

Well gents, I just got the trusty dusty Exploder back from the mechanic and it's like a brand new beast. I have power I didn't even know I was missing, better fuel efficiency, and unfortunately still a little bit of a chirp. It's not near as bad as it was, so I'm guessing the flex plate wasn't the sole source. Any other ideas for chirps? It's definitely coming from the back of the engine, it goes away at higher RPM now, is much more intermittent with the new flex plate installed, and still happens with the belt removed, so it's not accessory related.

Thanks!

 

[92exp4x4]

Worn or bad torque convertors can cause wierd noises. The forklifts I worked on, had automotive TCs in them. When the clutches were bad the convertor would screech and scream. I don't recommend this for your Explorer but we would test them by basically neutral dropping the trans with a full load on the forks and pulling a ramp. Keep in mind a forklift is governed to about 2800 RPM max, Even though thay are automotive engines capable of 5 or 6 grand.