haygeebaby

Took off the engine tray to lose some more weight off the rear end. Since then I get this rattle noise when I drive - but it doesn't make the noise all the time - only at certain revs. Sounds like it's coming from the engine driven fan. Anyone had this experience ?

black ice

Maybe not related. Do you think it could be a bad fan or alternator bearing?

dave

hyphenf15

I have not had that problem with the tray removed. +1 on the fan bearing.

993James993

When my fan hub bearings went south, the noise did not seem to be related to certain revs. And I would not describe that sound as a rattle. It was much more intense and immeadiate than a rattle. I would compare it to my burr coffee grinder when it runs out of beans.

I just took off my engine tray last weekend and found that one of the exhaust clamps had broken. I also understand that you can remove one of the mounting brackets along with the engine tray-I think it is the bracket in the back but not yet certain. Either of those could be the souce of your new rattle.

trickydisco

Maybe it's a loose baffle in one of your mufflers.

bpras@msn.com

Probably not related but check your center tail light. If it is loose or not installed correctly it can make a sound like dragging fingernails over a chalkboard when it starts to vibrate. Took me weeks to find this rattle because it sounded like it was coming from the area of the air intake.

haygeebaby

Thanks for the tips boys. I also did a search and found out some more information. On closer inspection today with a friend, we can see that the noise is coming from the engine fan and there are some scratches on the bottom of the housing. Will take the beast into the garage tomorrow to get a quotation on the work and new parts.

Anything I should also do while this is being fixed on the car ?

Cheers - this IS a great place.

Robin 993DX

Sounds like the alternator bearing is going south. While you are at it also do the pulley update.

Cactus

Just curious on the pulley update.....are the part numbers on the TSB still the correct numbers for the update?

Robin 993DX

Last I checked it is still the same.

haygeebaby

Good idea Robin. Read about the pulley in other threads. Will changing to the RS dual lower pulley improve performance ? Anyone had any data on this ?

Robin 993DX

Yes improve performance but you might have running out of amperage issue, as the alternator is now spining slower at idle. As a race car the rpm is always high so there is no issue, but with A/C, power windows, stereo, defrost, ABD, ABS etc.... you might drain down your battery if you don't do a lot of high rpm driving.

MarkD

the improvement in performance from the RS pulley will be as noticeable as the weight savings from removing the tray

Doesn't mean it is a bad idea but it really is a small improvement

There are other +/- Robin mentions one of the potential negatives above.
The main plus being a simplier belt config, IMO.

haygeebaby

Well - might as well do it when doing the pulley. Minor improvements add up. Cheers guys. On the tripple lower pulley there are 3 belts. 1 to the engine fan, 1 to the AC, where does the other go to ?

haygeebaby

Um - just did a search on Pelican for the dual lower pulley - 993 102 050 41 - it cost $648.50 !!! Dang dudes. Is this the wrong part I'm looking for ?