Squeak/rattle in engine bay?

jsb96 · Postby **jsb96** » Fri Jul 15, 2016 7:14 pm

Hey guys, so a couple of days ago I became the owner of my first Eunos mx5 mk1!

I realised that when I put a larger load on the electricals there was a slight squeak, which I understand means I need to tighten the alternator belt. However before doing this I wanted to degrease the engine bay because it was a nightmare, after degreasing and hosing down with a pressure washer, when I started the engine I get a loud squeaking and a sort of rattling noise (looking in the engine bay its hard to see where it comes from) and when I put the lights on I still get that alternator squeal on top?

Any ideas where the noise might be from? And how easy of a fix is it?

StillIC · Postby **StillIC** » Fri Jul 15, 2016 7:44 pm

If the belt is starting to squeal then replace it rather than tightening it, to give it the best chance of gripping at the lowest possible belt tension. Having replaced alternator bearings on my last car, I figure it is best to minimise the load on the various pulley bearings to make them last.

Further, I believe that the short nose crank failures, on the B6 engines, are related to drive belt loads being too great for the crank nose; especially PS and AC belts out there beyond the crank nose. So keep those belts new/good condition, and keep them as loose as you can get away with (without slippage).

jsb96 · Postby **jsb96** » Fri Jul 15, 2016 9:39 pm

Is that the timing belt that needs replacing or the alternator belt? Are these jobs that I can do? Isn't the timing belt supposed to be extremely complicated to replace? Or is it best left to a garage?

jsb96 · Postby **jsb96** » Sat Jul 16, 2016 8:41 am

?????

taminga16 · Postby **taminga16** » Sat Jul 16, 2016 9:51 am

He is referring to the alternator belt. Let us know where you are that someone might be able to assist you.
Greg.

StillIC · Postby **StillIC** » Sat Jul 16, 2016 10:05 am

No the timing belt isn't squeaking and that's not what I was talking about. It is a toothed belt that is dríven by a toothed wheel on the crank and drives toothed wheels on the camshafts. I imagine your timing belt is fine.

I was talking about the V belts that drive alternator, water pump, air conditioning compressor and power steering pump. They can slip when they wear and age. This slipping can cause a squealing noise (which you mentioned you heard).

Without knowing your skill level or what you can or can't do, I am going to guess that if you have to ask whether you can do a job yourself, you can't do it yet. Whatever the job. But I am sure you can learn to do it, if you choose to. Replacing V belts isn't normally a difficult job, but on the MX5 the alternator/water pump belt is a PITA to work on due to the location of the tension adjustment at the alternator.