Topic

After the pain of getting my wife's MGF through its MOT she was driving it back from work today and it's started making a loud whining noise from the engine.

When flipping the throttle by hand and listening from the boot aperture it seems to be coming from the inlet manifold area but i haven't had the engine cover off and had a good investigation.

It's a 98 1.8 non VVC.

Any ideas what it could be or where to start looking?

Cheers

Dave

Hazarding a guess bearings in alternator

GT MG SPARES LTD wrote: wrote:

Hazarding a guess bearings in alternator

Yes sounds like a good call

Took the alternator belt off and the noise is still there. It's quite hard to describe but the engine note seems to be a much higher pitch than it was last week when revved.
I've also taken the timing belt cover off and the belt is not seated centrally on the cam sprockets and showing clear signs of wear (hopefully photo attached) it's showing wear on inner and outer edges so possibly is off centre the other way on the crank shaft.
I was planning on replacing the cam belt anyway and have the kit but don't have a water pump or oil seals (one is leaking and needs replacement) so don't want to do the job twice.
Not sure if the belt/tensioner/water pump is causing the high pitched noise as it's not obviously coming from there but it's certainly making some noise.
Sprayed some contact cleaner around all the inlet manifold and breather pipes and there doesn't appear to be any vacuum leaks. Assuming the timing belt isn't the cause of the noise what parts around the inlet manifold/top end of engine could increase the pitch of the engine note?

That belt looks distinctly dodgy! Looks like it has been rubbing. Definitely needs changed sooner rather than later. Is the noise still there with the cover off?

Could you do a little video/audio of the noise and post it up? Youtube or something...

Could the problem be the crankshaft pulley ??

The noise is still there with the cover off but it is only the top cover that i've taken off.
Having slackened off the belt the water pump is very noisy when turned by hand so i imagine it would be even worse with the engine running. I will try and take some video/audio on my phone later and upload it but this may be beyond my technical capabilities.

So at the very least i'll be replacing the timing belt, water pump and cam shaft oil seals. I've done this before on an old rover 214 K series but the access was a lot better. Not looking forward to doing it on an MGF.

I would say that the wear is showing that the belt is rubbing on something, possibly the cover. This will probably be causing your whining noise.

I wouldn't run the engine with a belt that worn as it could fail.

I would remove the rest of the covers. You should see a witness mark where it is rubbing. Not sure what would be causing the belt to be off centre, but it might not be tensioned enough.

What worries me even more than the wear on the edge is that the belt only looks about 2/3 of the width that it should be. I think it is a lot more worn than you may think.

Well it wasn't the water pump itself that was noisy but upon closer inspection i found an alan key bit (the one for the tensioner pulley) wedged between the cover and the water pump and this was pushing the belt off.




You may be able to see in the photo that it is worn considerably in the middle. Must have been siting in the cover for a few years as the belt was changed 4 years ago and i've only taken the top cover off to have a look at the belt when i got the car about 18 months ago. don't know what caused it to shift yesterday and wedge itself where it did, fortunately it made enough noise to investigate the problem.
At least i know what i'm doing over the bank holiday weekend now.

Is the engine mount easy enough to undo/remove to enable the new belt to be fitted?

Removing the engine mount isn't too bad. I would take the weight of the engine with a crane, undo the 2 main bolts in my pic and then the bolts that hold the mount to the subframe and move it out of the way.

This leaves you with plenty of room, like this:

Thanks CJJ,

I haven't got an engine crane, could i support from underneath with a jack and a plank of wood to spread the load across the sump?

Yeah an axle stand underneath the sump with a peace of wood will be fine that's what I normally use when doing this job.