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MG MGF Technical - Overheating

As if to remind me what it was like driving my old mini years ago, my F has started to overheart in stationary traffic.
Before I take it to the garage I thought I'd see if anyone had any DIY suggestions. The odd thing is that holding the car (out of gear) at 2,500 revs for a couple of seconds and then releasing seems to make it start cooling, it gets back down to normal then starts creeping up again.
The car has just been for a service and thought maybe there could be cable or two I could check to make sure it hadnt become unplugged?

Pealy
N23TPM

Pealy

Was the coolant replaced at the service? If so I'd suggest that there's an airlock somewhere. Reving will make the waterpump turn faster and may force some liquid past it (I think).

Check to see if the coolant level has dropped in the header tank (wait for it to cool a bit first) - if so take it back to the garage and ask them how much they put in.

9408 SD 76
Hugh

Did they change the coolant during the last service?

If so it could be an airlock in the system.

Either way get it checked ASAP as the overheating of the *F* is one of the factors in the 'Blown Head gasket' saga.

Ted
Ted Newman

Hugh

SNAP

ted
Ted Newman

had this too back in June. Turned out to be a faulty coolant cap (see Dieter's site how in detect a faulty cap)

Same thing: overheating in idle only, faint white smoke coming out of engine bay, but no pissing under car... ;-)
Dirk Vael

Does the electric rad. cooling fan cut in? If not perhaps the engine temperature sensor is at fault.
Paul

I too had to replace my coolant cap.

After a reasonably good run, if I switched off water would p'ss out of the cap.

replacing it fixed it straight away. (and of course the old one LOOKED fine)

Julian

My F uses to overheat in stationary trafic too, despite the coolant fan. I was thinking of parking on the side of the road (I started to imagine people laughing at me !) when cars started to go faster. Then the coolant temp dropped quickly.
I have few leaks from the coolant cap too. I talked about it during the last service and I was told it was normal : "when the pressure is too high in the tank the excess of pressure is evacuated through the coolant cap and it condenses on the outside of the tank". Did they fool me ? Do you think I should change the cap ?

Jérôme

now 121 CCK 92
Jérôme

>Did they fool me ?

In Germany at any gernman dealer I would say YES.

Do you think I should change the cap ?

Jérome,
compare the inner side of the cap with the picture on my defects webside.
If the centre rivet is a little amount out of centre the go for a new one. Its cheap !

http://www.fortunecity.de/hockenheim/senna/253/defects/index.htm
See Row 2

If you have an MPI built before VIN ?? (see my VIN webside), then the air inlet manifold sealing could leak to the inside of the airintake manifold. (see above webside at row 3)
But you will realise both failures by slightly water loss.

BTW the inlet manifolds sealing is changed here in germany at nearly each MPI built before January? 1999 recently under goodwill or warranty. (according to the amount of MGF that I know)

Cheers
Dieter
http://mgf.tech.here.de
Dieter


Viele Danke Dieter, aber ich kann nichts sehen !!! "Datei konnte nicht gefunden werden" ....... that's what I was told over there ( http://www.fortunecity.de/hockenheim/senna/253/defects/index.htm )
I bought my MGF at Rover but it's a second hand one. They made a warranty for it. Do you think it can be covered ?

Jérôme

http://www.fortunecity.de/hockenheim/senna/253/defects/cap.jpg
or
http://www.fortunecity.de/hockenheim/senna/253/defects/
fails too ?

:-/ I can't find any problem to load it but heard of other friends that that free account has sometimes problems.
:-/
If not, then see the pictures on
http://home.t-online.de/home/dkoen/mgf_ersa.htm
----

I just looked up your VIN figures :) ...
If its an MPI then go to your dealer and complain slightly water loss. Tell them you fill it up each 2 weeks. ;-)
They shall measure with their equipment wether it can be possible that the inlet manifold sealing leaks.
If this does not work recently, then ask for a MG Bulletin technique of February 1999. related to that part change at VIN 504633 onwards.

The coolant caps bulletin is much older and does not face any change.

IMO it does not matter that the car is a second hand one. This failures are probably faced under goodwill (not warranty) for you. But that depends on the complete sequence of 'service' dates (annual mainservices) in your service manual.

Hope this helps
Cheers
Dieter
Dieter

Ahhhaa

My car was plagued with this problem just about everytime I was in slow moving traffic while on holiday in France in August - about 2 weeks after its 36,000 mile service. Is the coolant changed at the 36,000 mile service?

Of course the problem went away as soon as I got back home. My dealer suggested that cause would be corroded connections on the temperature sensor - which apprantly is a brown plastic block on the nearside if the engine. However my car was a full 3 weeks out of warranty by then so it never got checked and the cars been fine since.

Paul
P9 VLS
Paul

Yes the coolant change is first done at 36,000 miles then every subsequent 24,000.

Rog
Roger Parker

Jérôme
Definitely change the cap.

As I said, I used to loose at least a pint after a long run, sometimes 2.

Replacing the cap has completely solved the problem, and I haven't needed to top it up since.

Paul, my problem also manifested itself on holiday in France. funny how they pick their moments! Actually, it was on the way to the Portsmouth Ferry this September, which I consequently missed as I didn't have any water with me. Bah! Waited 1hr45mins on the A33 (A30?) about 25 mins from portsmouth for the bluddy AA. Topped it up, bled it and off I went. Missed the seacat and had to get the stinky night ferry.

it was worse in France as it was sometimes 35 degrees!

anyway, I digress...
Julian

coolant cap GRC 1184
I remember the price about only 3 GBP ?

BTW the technique of this part is common at other cars (probably not the temperature rang !!)
The cap in my Ford Fiesta Diesel looks equal, but I have'nt checked details.
Dieter

okay, my book is at home and I thought i'd just check the coolant level, the white tank on the right hand side of the boot, under the flap, it isn't supposed to be empty is it? There's are dregs of green liquid but I reckon it should be full of it right? How much should I top it up, what with, and do i need to do anything else like get air out?

Please help, preferably before my office shuts tonight!

Pealy.
N23 TPM
Pealy

Pealy,
find filling marks on the left side of that tank. (remove the flap and mesh part completely to see them)

Or, fill app 2cm above the half area of the tank.

Or look inside the tank through the filling hole there is a mark moldet which indicates the filling level too.

Remember or mark the level to which you filled the tank and check from time to time at cold engine this level. It will variate a small amount. 5 or 10mm difference do not matter IMO.

Cheers

Dieter
PS as long as you see green stuff, nothing bad will happen :)
Dieter

Julian "Topped it up, bled it and off I went" how did you bleed it ?
Jon Baker

Jon
I used the bleed valve. Obviously. ;o)

its under the bonnet, under the big black plastic cover, above the washer reserve bottle, kind of between the wiper blades but lower.

Its a nipple type valve which you unscrew to let the air out.

Basic Procedure:
Fix leak,problem etc.
Add water.
Run engine until water level is stable.
Turn heater on full
bleed using valve until liquid starts coming out with no air (engine still running)
Tighten
Switch off
Check levels
Relax, have a Dr.Pepper
Blast around the country and check again.

I think there is much more complicated way of doing it as per the workshop manual but I don't have one.
Julian

Thanks Julian,

As well as adding water wetter I think bleeding any air out of the coolant maybe safeguards against head gasket failure.

Jon Baker

..If anyone's looking for closure, it turned out to be a leak from the 'Inlet Manifold Gasket' whatever that is, should I be worried, it has the word 'Gasket' in after all!

Pealy.
N23TPM
Pealy

Hm,
I think we should start to bet at next MPI-'overheating' time.
(I won) :-/

So again and again and again >:-/

All MPI Drivers with a car under VIN 504633 my be very sensible on overheating signs !!
I recommend to ask your dealer wether it was changed already to the new red coloured one or not.
The part is really cheap and works is IMO only one or two hours to change it !
Part Number GUG704094MG, IMO a must for all MPI owners.

Can't someone write this in an understandable english for the FAQ ?
Take the picture:
http://home.t-online.de/home/dkoen/sealing.jpg

Sometimes I really feel like a 'Mum' with naughty children in a kindergarden ;-)

Cheers
Dieter
Dieter >:-(

Sorry but what is a Mpi ????????????????
(oo)

Mpi = Multi point injection as opposed to VVC

Regards Tim
Tim Sheppard

... and thanks fly to Terry Cox for his consumtion in the thread:

'The K Series head gasket failure'

Unfortunatly, is the 'altavista' output from english to german only crap, so I'll have hard work to translate it for my only german speaking friends. :)
Dieter <:-)

This thread was discussed between 22/11/1999 and 29/11/1999

MG MGF Technical index

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