MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - What's that noise? Now I know...

A week or two ago I mentioned that my F was making some odd noises - an extra exhaust tone, a chuffing noise from the right side of the engine when cold, and a separate ticking sound (later found to be the oil filler neck rattling free of its mounting).

I got a few opinions - and although no one was able to confidently say what the noise was, common things occur commonly and the consensus was that the flexipipe had finally given up the ghost (68k miles and 7 years ain't bad).

Andy and I got the car up on axle stands after the rolling road tests showed the car to be down 10bhp last saturday: but there was no obvious exist of exhaust gas - but the leak could have been concealed from above.

So I ordered a very competitively priced flexipipe from Victoria at the MGF Centre, and took the car this afternoon to Tech-speed.

Amazingly, the pipe came off easily - none of the studs had seized!!! 8oO (You're going to be astonished by this, I know Andy! ;o)) As far as I know, this pipe has not been touched for seven years, so how come it was so easy to remove, I have no idea.

Inspection of the removed flexipipe showed absolutely no evidence of exhaust gas leakage whatsoever. Even the wire braiding remained perfectly intact. With an air hose and some gaffa tape to seal the ends of the pipe, Greg checked the pipe under water for leaks - and no leakage!

Mick quickly identified the problem (that I've not come across here before): one of the exhaust manifold studs had worked its way loose, allowing exhaust gas to blow past the exhaust manifold gasket.

No fresh gaskets to hand, a temporary measure was to simply tighten the manifold stud back into the block, and re-tighten the manifold nut.

Result: manifold now gas-tight :o) Engine now quieter - and those 10 horses feel as though they're back where they belong :o))

Just had a terrific cruise home - roof down, despite the rain :o) Oh the joys of MG ownership :o)

So big thanks to Tech-speed for sorting this problem out for me in a much quicker time than I'd ever be able to manage it, and also to Victoria at the MGF Centre for the replacement flexipipe, even if it wasn't needed at the end of the day :o)
Rob Bell

Glad to hear it was so simple Rob - one more little piece of experience to chalk up for the archives. Oh, and one more endorsement for using trusted specialists - well done Mick and the gang at Tech-Speed.

Dave
Dave

Nice one Rob

Good to hear your exhausting gases from all the right places again.. Did you leave the old flexi-pipe on? or change it anyway?

Stu
Wokingham
S.C. Dickens

We put the old one back on - there was nowt wrong with it (except being very very flexible! ;o))
Rob Bell

Hi Rob,
good to hear that the flexipipe can survive so many years of intense use ! But from what you described above it seems that there is no bracket in place ? It is to my understanding that this cheap simple "add on " exthaust bracket not only secures the long downpipes from too much vibration but also might contribute to less stresses on the head and gasket...... IMO well worth a try even if the thing is a pig to fit as one need access from both above and below.

BR, Carl.
Carl Blom

That's a good thought Carl - but I plan some time in the near future to source a 4-2-1 exhaust manifold from either EBD or Janspeed. A support bracket might be useful for one of these - but I suspect that the standard item will not fit (is there a picture of this part on Dieter's web site?)
Rob Bell

Yes there is Rob (where is another matter entirely!) The bracket is a plate that is bolted to the block and retains the flange joint where the manifold meets the flexipipe. It is very tricky to install (mainly due to access), but is a recommended bit of kit IMO (not that i have one).

Glad it was no more serious than a loose nut, i think i'll name your flexi 'Timex' "Takes a likin', keeps on tickin'..."

:-)

SF
Scarlet Fever

>>i think i'll name your flexi 'Timex' "Takes a likin', keeps on tickin'..."<<

ROFL!

Andy, you should have seen it: the flexi looked absolutely pristine! Just a little surface corrosion here and there, but every single wire in the mesh was completely intact. Amazing.

Perhaps a function of the driving I do? i.e. not many short trips, but a large number of longer journeys...?
Rob Bell

And not too many speed bumps altercations. I can't believe you can avoid them too much around MGF Central (Muswell Hill).

A 'tickin' flexi would be a bit annoying !
tim woolcott

Don't talk to me about speed bumps!!! But at least I've moved away from Highgate - there are some truely evil bumps around there that'd pose problems to mountain climbers, let alone lowered MGFs!

BTW it is the front toe-hooks that get most of the bashing - the flexipipe and cat are relatively well protected.
Rob Bell

Rob,
I experienced the same problem a few month ago, and I reported here... I re-tightened too the bolts securing the manifold.

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&mode=archiveth&subject=69&subjectar=69&thread=2002123114145116887
(at the end of the thread)
But in my case, there was also another problem : the cat was restricting the gas flow and causing a major power loss.

Anyway, good news you didn't even have to replace the flexi-pipe.
I'm looking forward to see your future 4-2-1 manifold.

BTW, I fitted the exhaust manifold bracket last year : it's a pig to fit, but it's worth it IMO.
Fabrice

Thanks for sharing that Rob. I will be inspecting mine for the same problem ASAP. If I can't find it I will have to nip in to Tech Speed for some advice. They're only 15 minutes away:¬)

Bruce
Bruce Caldwell

>>They're only 15 minutes away:¬)<<

Nuts! They're the best part of 2 hours away for me Bruce...

Been getting similar noises?
Rob Bell

This thread was discussed between 20/05/2003 and 22/05/2003

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now