fred_720

I have a 1998 ford mustang, 3.8L, and recently it stared to squeal really loud on startup. It was high pitched and just about disappears when I start driving it. I took it in to a mechanic and they originally thought it was the alternator/serpentine belt. So they took that belt right off but the squealing persisted just as loud as before.

They said they thought it might be the timing belt (even though its a chain, same difference i guess) which would require a lot of work and money. I didn't think that timing chains squealed like that so i'm wondering what else it could be. I don't want them to do $800 of work only to find out it isn't the timing chain.

Any ideas what it could be?

petrock

Good to hear your mechanic just throws parts at a problem instead of actually diagnosing it. I'd find a new mechanic. Just sayin'...

The squeel could be a lot of things. I'd pick up a mechanics stethoscope from your local auto parts store ($6) and poke around a bit. I'd suspect one of the pulley's that the serp belt runs around is bad. Also check the belt tensioner to make sure that it is providing enough tension on the belt. If its loose it can cause your squeal and other issue. When the vehicle is running, check if the belt tensioner is pulsating up/down. If it is, then its worn out. Good luck...

03shadow

yeah a mechanic would jump to something that they will surely charge you at least a grand for. its most likely a pulley, like petrock said

neo8222

i say get a new mechanic just cause he can't figure out the difference between a over head VALVE and an over head CAM motor... timing belt on a OHV mustang.... dumba$$

also fyi the timing chains and belts are the same in the since that they both time the valve train to the rotating assembly but thats about where it ends.

mustangmike09

so before the responses fail even more.

If they took the belt off and it still making the sound. Then its not related to the accessories. . . that was step 1 diagnostic.

You do have a timing chain, and its not that hard of a repair if that was the case FYI.
But id look into the CPS first. (Camshaft position sensor) this is a shaft that spins by a gear connected to the camshaft gear. It also has a shaft that runs the oil pump. These are known to somehow "go bad" and squeal as described. I would do some searching about that. If thats the case, very easy change.

desertt5

The CPS is right behind the water pump. Just repalced mine last month. As mustangmike said, not a bad job change it out.

du907

Does the CPS have to be positioned "just right" like a distrubitor would be since it is basically taking the place where a dist. would be if it was an old style motor? Or when replacing do you just unplug it take the retainer off put a new CPS in and plug it back up.
Just curious.

scoltharp

My 07 just started doing the same thing recently. It squeals right when it turns over but goes right away. Would this be the same thing?

desertt5

Check here, It does need lines up before you pull the old one out.

https://mustangforums.com/forum/v6-1...-replaced.html

desertt5

I guess it is possible. I would follow mustangmike's post to narrow it down.