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MG MGF Technical - Rattling & Loss of Power

S reg VVC, just had HGF fixed couple of weeks back and belts changed at the same time (due at next service). No problems until today, accelerating away from a roundabout, loud rattling noise from behind. Rather like several stones rattling around in a wheel arch but clearly from engine. Some loss of power but not total loss. Only a mile away from homw when it happened, so now sitting garage. Any ideas what this might be ? Something to do with 2nd belt on a VVC ?
Davey

Could be any belt back there that has torn but not broken. The alternator belt you can check yourself for a large part.
Belt placed wrong way round??

It could be something hooked in a wheel as well.

Johan
Johan Slagter

Trust me the rattling will be this:

*****************

I finally found the source of the annoying buzzing sound between 2000 - 2500 RPM

After changing the exhaust manifold gasket, fitting the downpipe steady bracket the noise was still there.

I suspected the flexi pipe so I ordered up a new one of those but whilst changing the oil on Saturday I found the culprit.

It appears the oil filler pipe was loose. The bolt that holds it onto the inlet manifold was in place and screw in as far as it would go but it was rattling about here. There is a clip near the top of the pipe which holds two pipes but one of the pipes wasnt clipped on which must have been allowing the filler pipe to rattle around.

The pipe which wasnt attached couldnt be clipped back on securely so I had to take out the bolt holding the filler pipe to the manifold then put a washer on it and screw it back in.

It's now held securely by this bolt with no need for the two upper pipes to be clipped on to secure it in place!

All this after I forked out £80 on a new flexipipe which I probably dont need but after being told "It's definitely your flexi-pipe" about 100 times even I was convinced!


************

I have some pics now of the offending bits. Let me know if you want me to send you them.

Bob Millar

Thanks for the input Bob. I'm pretty ignorant about these things and perhaps I should have been a bit more specific.

When I say the rattle was like stones rattling around in a wheel arch but unable to get out,it was like loads of them in there but clearly coming from the engine, to the right hand side I guess. A chain breaking might be another way of describing it. The rattle has gone but there is very obviously something wrong - sort of misfiring and chugging.

Davey

Trust me I had the same sound. Like someone rattling a stone in a plastic cup and coming over my right hand shoulder. Give me your email address and I'll send you the pics. It's worth a look. Especially after I spent a fair bit checking over the exhaust and replacing bits.

You can email me at

bob @ mruk.co.uk

Just remove the spaces either side of the @
Bob Millar

Rattleing is BAD, could be a number of things,

The cam belt might have slipped a tooth, if so then it's new engine time (garage should pay)

The alt belt might have partially snapped (did you replace the alt belt at the same time?)

Hopefully it's just the exaust manifold gasket, which is 15 mins with a 15mm spanner job:
Take the engine cover off, then check all bolts on manifold, if one (or more) is loose or missing then you have found your problem, if not then try listening around the engine bay, use a length of garden hose as a stethascope, but keep it clear of the alternator pully.
Will Munns

Bob is right. After 2 years hunting, and I do mean hunting I have green felt all round the engin bay.! I found it last weekend. If Bob is talking about the clip that holds three pipes and that one of them was uncliped then that is it. Mine just needed the rubber on the pipe moved down the it clipped in fine. I am now all rattle free.!

:)

AndrewMc

Loss of power no idea, sorry.
AndrewMc

Thanks for the input Will.

HGF was fixed by dealer I bought the car from under warranty but I am beginning to worry about the quality of the work this happening so soon thereafter.I'm not technically minded at all so I guess its time for an appointment at B&G.
Davey

Nope, take it back to the dealer, if there is almost anything wrong then it is connected to the Head gasket job, and so should be free. Exaust manifold and inlet manifold have to come off for HG chnage, belts are very costly if they go wrong, and the garage made this fault by setting the tension wrong, if it's that. In fact the only thing that might cost you anything is an alt belt snap, but they usually go fully, belt is very cheap, and they should do the job for free, cos they refitted a clearly worn belt.
Will Munns

>The cam belt might have slipped a tooth, if so then it's new engine time

My money is on this being the answer. The symptoms described exactly match those that I had when the cam belt tensioner broke on my F. This resulted in the belt slipping around and me part exchanging the F for a ZS.

Ralph
Ralph

Thanks Ralph. Were you able to drive the car after this happened ?
Davey

Just to chuck another thing in - a friend has suggested it might be the catalytic converter breaking up. I'm not qualified to express even a vague opinion but what do others think ?
Davey

Possibly, the hose trick will show you where the noise is comming from. Cats usually rattle and break up if you throw fuel at them when they are hot, for instance stalling and restarting after pulling off a motorway.
Will Munns

Unfortunately, I can only add another voice to Will and Ralph's pessimistic opinion on the rattle and loss of power. Unfortunately, it could very well be something to do with the cam belts/pulleys :o(

I also agree that the dealership who repaired the car ought to sort this out for you (although I know what you mean about going elsewhere to somewhere you trust!)
Rob Bell

Thanks Rob. Would that be consistent with the rattle now being gone (it lasted say 10 secs max.) and the car being driveable ?

Anyway, car going back to dealer next week.
Davey

I'd remain suspicious Davey - especially as the consequences of a VVC failure are very expensive :o( I would, however, have expected the sound to remain if this were the infamous VVC cam rattle...
Rob Bell

If it is the cam belt that's slipped then the car should not be driven - it will only do more damage. When mine happened I coasted into a bus layby and then waited for the RAC to turn up.

>The rattle has gone but there is very obviously something wrong - sort of misfiring and chugging.
I missed this bit before. This also sounds like a timing problem. Unfortunately, I think Will might have been spot on with his first guess. :(

Ralph
Ralph

This thread was discussed between 11/03/2004 and 12/03/2004

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