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View Full Version : strange knocking noise - any advice?



eliZium
06-06-2005, 07:32
Good morning :)

(actually not so good - had a nightmare weekend trying to locate a strange knocking noise).

This weekend I did some minor tune up stuff, changed plugs, fluids, filters, camshafts, belts...

After putting it all back together again I noticed a strange 'knocking noise' at all RPMs which sounded like it was coming from the front of the engine.

I first thought that maybe after changing the cams it may be related to ignition timing being a bit out or the cams being timed incorrectly, but I was hoping not :)

After giving some more thought about where the sound was coming from I removed all the accessory belts and started the engine again - there was no knocking noise. *Phew*

I put the belts back on independently (except A/C as I've decided to remove the A/C anyway). The knocking noise was only present when the alternator/waterpump belt was in place.

I changed out the waterpump and the noise remains. If I slacken the belt until just before it starts squealing, the frequency of knocking decreases to 'intermittant'. If the belt is squealing then the knocking goes away.

My current feeling is that it is the bearing in the alternator that's shot... but before investing my life's savings in getting a new alternator from Nissan, I wanted to get some other thoughts on what else the noise may be?

Your thoughts greatfully received.

Chris

PS: does anyone know the part number for the alternator for an NA S15 (and also front main seal part number as it is a little leaky - my local Nissan dealership in Moscow claims to be unable to find part numbers) :)

Nicely
06-06-2005, 07:44
You may want to stick a post in S14 Tech pointing to this one. :)

Haven't got clue myself. :(

Draven
06-06-2005, 07:59
to be honest, i would think you would be best off looking around locally for a reliable company to refurbish the alternator

i can only imagine that the price of an original alternator from nissan would only be classified as "scary"

might be worth checking the water pump for peace of mind too, if that goes your screwed

eliZium
06-06-2005, 08:13
Draven, cheers ... the water pump is new - I changed it as part of my diagnostic procedures - fortunately when I was in the UK in March I was able to pick one up at a dealership near where I was staying. The knocking sound was there before and after chaning the water pump so I'm fairly certain that isn't the problem.

I will get the wife to find out about places that refurbish alternators... I still don't understand the local lingo enough to do that myself :)

Nicely
06-06-2005, 08:25
You just speak slower and louder. :p

I expect one or two more suggestions will appear after the 9am water-shed. :)