PontiacBonnevilleClub.com

Noticed this last week on my 94 Bonneville NA engine:
the water pump pulley is right next to the engine support arm where there is maybe less than thickness of sheet of paper between the 2.

I thought maybe a slightlly smaller-diameter (by ~ 0.25" or so) pulley would be the way to go ... so ... I found that Dorman's 300934 pulley is spec'd at 5.09" diameter ... so ... I measure the pulley diameter that's on there now (with a caliper) and was somewhat disappointed to see that the Dorman pulley diameter spec is spot-on same as current pulley.

So: now I'm thinking that I should take the pulley off the pump and take a file to remove some material from the engine support arm ... but ... that is counter to what was engineered in there.

Bottom-line is that I am uncomfortable thinking about in the future when the water pump bearing gives way and the shaft starts to wobble then there's going to be sparks flying due to a wobbling pulley contacting the engine support arm.

Any experience out there regarding this ? .... suggestions are welcomed.

In my 10+ years of forum experience, this is the first mention of it possibly being a concern.

The worst collateral damage I have ever heard of from a water pump failure has been the impellers digging in to the timing cover. The belt tension tends to prevent a wobble like you are concerned about, and if it were to be bad enough, the pulley would just start to tip down until it dumps the belt off of it.

I think you should ignore it, unless you have a massive fuel leak in your engine bay, which could cause sparks to be a concern, then you may wish to address that.

Thanks for reply ... no fuel leakage that I know of in the engine bay (took the fuel injectors out ~ 18 months ago and ran B12 Chemtool thru them with an ~ $10 home-made injector cleaner I saw on YouTube with a syringe and FI-connector and 9-volt battery and momentary push-swithch... cleaned-up the injectors very nicely ... then used new injector o-rings for the re-install).

The pulley near-contact point is the rear-edge (engine-side) where the engine support-arm curves ... it's really close ... and I'm not comforable with it ... so ... perhaps tomorrow I will remove the pulley and then do some hand-filing into the support-arm curve ... not too much ... just to get some clearance to make me feel comfortable with that situation.

Slight correction to my last post: the near-contact point is the back (engine-side) of the pulley to the engine-support arm ... but ... not the curved part of that support arm but the flat-part of the arm that is against the engine ... and ... not for nothing ... maybe it's is my imagination (or maybe not) ... it looks like the back of the pulley has already worn a very very very slight curve into that flat-part of the engine support arm.

But no noise (eg: grinding) at that near contact-point when idling nor driving ... and no other indications of an issue ... or than the visual that I described.

Of course: when I take the belt off ... before I take the pulley off (to hand-file the engine support arm a bit), then I can feel whether the water pump shaft currently has any play in it.

But currently doesn't appear to be play in the water pump shaft via viewing while idling or attempting to shake the shaft when engine is off (but with the belt on).

Final note (may be a clue, maybe not): ~ 2 years ago I bypassed the A/C compressor with a shorter belt (found the shorter belt# in 1 of these forums) ... the shorter belt worked very nice as a "cheap fix" since the A/C compressor had started to make a grinding noise and I didn't (still don't) have time to change the A/C compressor (etc, etc that would go into making the A/C work again).

I mention this because the shorter belt then contacts the water pump pulley on the towards-the-rear face of the pulley ... which means the belt exerts a force on that pulley towards the front of the engine ... towards that engine-support arm.

Yes, I know the only way the water pump shaft would allow the pulley to actually re-position slightly forward is if the pump shaft is significantly worn ... which as I mention above: currently appears to not be the case (but I'll find out more after I take the belt off ... maybe tomorrow).

Thanks again for the prior feedback.

Is it possible to post pics of it by chance please? I didn't realize it was possible to short belt the engine, much less for it to actually rub.

Thanks for your interest, here you go - https://drive.google.com/folderview?id= ... sp=sharing

I wouldn't worry about it.

ok ... so onto other higher-priority to-do items ... and I'll save hand-filing that support-arm near-contact point until the water pump needs to replaced in the future. Thanks for your feedback ... it lowers my concern-level regarding this situation.