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MG MGF Technical - Please help ! Noisy Engine - poor mpg

I have an 8 month old 1.8i MGF. It has covered 5500 miles.

Recently (this last week) I have noticed that the exhaust sounds very noisy, ie. very 'throaty' and rough. I think that I have also lost some power, especially in lower gears.

Top speed also seems down.

I was doing 100 mph today (on the Autobahn) at approx 4500 rpm and the exhaust was definately very very noisy and there didn't seem much "oomph" left in the car.The MPG is also down. I have used 25 litres (half tank) to cover 145 miles (most of that was at between 30 and 60 mph - the 100mph was only for a brief test).

I have checked the exhaust for obvious damage, as this was my first thought (had my wife grounded the car and not told me ? !!!) but there are no obvious signs of damage.

Was else could be wrong ?

Timing ?
Faulty spark plug ?
air filter ?

It has been very cold here (down to -12 degrees) and very very windy when driving, could this make a difference to MPG ?

Any help would be gratefully received.

Anything I can do 'self help' would be useful rather than try and find a Rover Dealer locally (my local dealer closed last month and I reckon the nearest is now 2 hours away !)

Thanks again, best regards from Germany.



Carl , it doesn't sound good, try the spark plugs first, but I suspect a sticking exhaust valve , what other symtoms do you have ?Check colour of each plug to see if it is a particular cylinder that is causing the problem, check that the air intake side isn't blocked or the rubber hoses havent kinked and causing a restriction,good luck. Have you put the wrong fuel in? Is their a misfire? mike.


I've just had a look at the spark plugs, they all seem fine (if not the easiest things in the world to get to !). I've checked the air intakes and everything seems fine there, there is a very small rattle on the drivers/fan side.

As regards other symptoms, the only other is that the car is that the exahust is producing a little more smoke than I would expect. The car is very noisy even when idleing. (My wife's 6 year old Clio Diesel is quieter at the moment !). The only other point I didn't mention is that the car has not been driven (at all) for 2 months.

If it is a sticking exhaust valve would that be covered under warranty ? If not do you reckon it an expensive job.

I can see that finding a Rover/MG dealer locally is going to be a problem !

the only thing what I can recently add is:
- Outlet manifold cracked ? (hard to find, but can be found app.)
- do you have coolant loss ?
- any sign on water damps in the engines oil ?

If you need actual help in germany then call me 02133 210616. (until 12 pm :). I've got the actual dealers list and the register of MG-Enthusiasts of the MGCC Germany for probably local help.


To check for exhaust leaks do this when the engine is COLD, otherwise you burn your hands on the exhaust!!!!

Get two pieces of card or paper folded over several times to get a thicker medium. Start the car and allow it to idle. Place one piece of card over the end of each exhust tailpipe and hold it firmly against the pipe so as to seal it. If there is a leak then the idle will continue at the same level and you will be able to clearly hear that there is an exhaust leak. If the exhaust is leak free then by holding the card in place you will actually find that the engine will stall. Also when you release your grip there will be a rush of exhaust gas from the now pressurised exhaust system.

A sticking valve does normally lead to a rythmic misfire as that valve doesn't seat and so that cylinder doesn't do much. Sticking valves is not unheard of in many 16 valve engines due to deposits coming from the current fuels. Additives in the fuel (injector cleaner, etc) help to reduce the conditions arising and can have some benefits with reducing it if it occurs. However if this is the case then only some of the professional (Trade only) additives are strong enough to provide anything other than a temp cure.

I would suggest that with a sudden start of the problem with obvious effect, if it is not the exhaust then i suggest you obtain some knowledgable advice sooner rather than later. I would not suggest that a two hour drive to a dealer is the best course as this may aggravate the problem to more serious levels.

I would expect that even though you do not have a Rover dealer to hand that there will be some motor engineers who can check out most thigs as well. (if not better!)

Roger Parker

No response,
so the german ROVER Info Service call is 01805 8282.
Or call the ADAC 22 22 22


I had this twice, and twice it turned out to be one dead sparkling plug. (first time the plug worked randomly, but not all the time). Anyway it has exactly the same feel as you describe. (noisy, loss of power, higher mpg)

but if that's the case you should feel a slight vibration when in idle mode. Is that the case.
Dirk Vael

Thanks for all the help so far guys.

Dieter, I will try the Rover information number, thanks.

Dirk, yes the symptoms do sound very similar, but there is no noticeable damage to any of the plugs. I hope that it is nothing more than a simple dodgy plug !

Thanks again.



I recieved your Email. The location you wrote sounds to be a good dealer.
I called for two MGF friends which are living there in B... and will hopefully get some more information.
So, things are running as good as possible.


... things happen like in nearly each help case at this BBS :)

A friend from our Dormagen meeting replied and suggested his garage. In case that Carl doesnt recieve my email in time....
-Royal Motors Bielefeld, Mr Hohnholz, (Tel. 0521/3040588)
Our friend Thomas F. can help on translations.

So long

This thread was discussed between 30/01/2000 and 01/02/2000

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