Squealing After Head Gasket Replacement (Page 1/2)
Fiero515 JUL 29, 03:16 AM
My nephew and I are working to restore an 86 Iron Duke. The car had a serious coolant leak and we replaced the head gasket as a precaution because we saw green stains on the engine block. However, it seems the leak was from the water pump.

After replacement, we torqued the head bolts to spec, we made sure to follow the same order when inserting pushrods, and followed the copious pictures we took during disassembly.

There is a squealing noise at idle when the engine is started that was not present before. The sound seems to be metal on metal. We have not run it for more than a few seconds. Our current thought is something is not oiled as the belt appears to be turning freely.

Thoughts?
Dennis LaGrua JUL 29, 03:20 AM
Squealing is usually the result of a loose belt not usually related to a head gasket problem. Cut a section of hose and use it as a stethoscope to pinpoint noise.

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Fiero515 JUL 29, 03:38 AM
We’ll double check the belt. Some added context there. We replaced the water pump. The first water pump I purchased from Rock Auto accepted the OEM pulley but seems to be too tall. The interior channel of the pullley aligns with the AC compressor, not the alternator.

I bought a second pre-pressed water pump that seems to be the right height but I’ve heard somewhere anything other than the OEM water pump pulley can cause problems. Am I on a possible right track?
Patrick JUL 29, 04:32 AM

Not being able to actually hear the sound ourselves, it's kind of difficult to diagnose... but sometimes a squeal can be a vacuum leak.
1985 Fiero GT JUL 29, 04:55 AM
While the engine was off for the part replacement, your battery would have drained more than usual, putting a larger load on the alternator upon first startup, furthermore, the belts hate coolant, if they get coolant on them, they can squeal more easily, and it is a horrid sound haha.
Fiero515 JUL 29, 04:58 AM
I will link to some video in the morning.
Fiero515 JUL 29, 07:55 AM
I’ll get some videos and pictures put up later this morning g to confirm.

Thanks so far!

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Owner since 2021
Enthusiast since 1994

82-T/A [At Work] JUL 29, 08:35 AM
The 1984-1986 model year Fiero 2m4 used a V-belt pulley... which was the absolute worst design I think anyone has ever seen. It was dramatically improved in 1987 with the implementation of a serpentine belt system, which used a belt tensioner. Unfortunately, the engine block itself was modified to accept the belt tensioner in 1987, so you can't simply upgrade to this. My daughter and I are in the process of upgrading to a serpentine system (minus the tensioner), which should be no worse (slightly better with more contact patch) to the 84-86 V-belt system.




As you can see though, the biggest issue is a lack of contact patch on the crank pulley... but again... it's no worse than what was stock on the 84-86 Fiero.

It's common for them to squeal / slip... even the slightest bit of pulley misalignment can cause the belt to slip, and as someone above me said... you get coolant on those belts (and the pulleys, and it essentially puts an oily glaze on it.

My advice is to replace the belt entirely... but before you install the new belt... take some brake cleaner and spray down all of the pulleys... and THEN install the belt. There's a little slot in the bracket that the top of the alternator attaches to. This is meant for you to be able to put in a crow bar so that you can get leverage to tighten the belt enough before you tighten it.


If you do this... you shouldn't have any other issues.
Fiero515 JUL 29, 08:57 AM
Placement on the alternator pulley:


Placement on the water pump:


All points are ok the most interior channel of the pulley.

Water pump is the Fiero Store prepressed.

[This message has been edited by Fiero515 (edited 07-29-2024).]

Fiero515 JUL 29, 08:57 AM
Sorry for broken image links, will redo them shortly.