Yet another "What's That Sound???" thread

[jthod]

yeah, I know vids over the internet aren't the best way to do this, but the video tells the story fairly well. It's definitly coming from the front end, but I don't know if it's the TB tensioner, or something else. The water pump turns smothly. I didn't take off the other accesory belt to check those parts.

my plan was to put everthing absolutly necessary back on and start it to better idedtify the noise.

'90 MTX obviously, 111k, new rod bearings, clutch, and top 60k as of ~104k.

her ya go:
SHO making a racket
revving after 5 minutes of warming up

 

[zblackbeast]

bad tensioner bearing possably? it could also be that Timing belt tensioner too.. sounded like my old 4.0 SOHC explorer. but that had a chain not a belt timing set...

 

[Storm-Chaser]

When did the noise start ? Immediately after the 60K was done? After the rod bearings were done? After some other maintenance was done? Have you pulled the valve covers or upper timing belt cover yet?


First, get a mechanics stethoscope and try to isolate the area the noise is coming from. Second, don't run the engine. Third, if you do have to run the engine for trouble-shooting, stop revving/throttle-blipping it.

 

[93rev2sev]

When were the rod bearings swapped out?

 

[jthod]

Rod bearings and top 60k were done around 104k, it now has 111k. Rod bearings looked brand new, and the top 60k went very smothly, with nothing out of the ordinary. Other than one valve needing an exceptionally large shim. I havn't done any engine work since then.

It just kinda started out of the blue. It actually started after I ran a full tank of regular through it, the first since I've owned it, and probably the first since the PO, my grandpa. I pulled the timing cover, and there was no rust colored dust, just rubber dust.

Like I said, I'm going to put things back together (other than the timing cover) and see if I can find it that way. The timing belt seems fairly loose, so maybe the tensioner let go. How tight is it normally? Doesn't seem like something that should have any give in to.

 

[twr]

Ejected shim??

 

[jthod]

God I hope not. It doesn't sound to be coming from the valve covers, but I may be wrong.

I'm going to work on it tomarrow night.

 

[93rev2sev]

I'd pop off the timing belt inspection cover and make sure the tensioner is set.

You don't even need to remove anything but the front tire. The inspection plate is there for reasons JUST like this.

 

[jthod]

That's next also, I was planning on doing the front 60k anyway, just not so abruptly. If it is the tensioner, I'm going to go ahead and do it now. I should either way, I know, I just don't have the cash right now.

 

[CobesSHO]

Sounds valve related to me. Back in the day, bad hydraulic lifters sounded like that, until they got pressurized with oil.

 

[itwonder]

Simple things first...Remove the accessory belts and run it to rule out anything in that area. Then go deeper.

 

[NebraskaSHO]

The sound is coming from the lower part of the motor towards the big pulley IIRC when I heard it last weekend. Doesn't sound like a rod, and doesn't sound like a valve related issue due to it's location.

I really think it's the tensioner or one off your ACC units.

Go buy a mechanics stethoscope, you'll need it for work any ways!