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MG MGF Technical - Help! Water temp overheat!!

Help and advice please!

Yesterday I sat stationary for approx 20 minutes with the engine on (basically to keep warm whilst my girlfriend popped into Asda!) - on her return we sat in very slow moving traffic for a further 15 minutes until she noticed large amounts of white smoke (steam) coming from the rear of the car.

I managed to get us off the busy roundabout, park up and open the boot where the stem was ousing out - by this time I'd noticed the water temp guage heading towards the "red"....

We waited around for about 15/20 mins for things to cool down before managing to drive the 5 minutes home.....seemed as we were moving the airflow into the engine was ok.

On examining the expansion tank today it is bone dry/empty.

What should I do now?

Is it a major problem?

Have I damaged the engine?

Do I just top-up the exapansion tank with anti-freeze?

Do I take it to be serviced/checked?

I'm by no means mechanical, but really need advice as I need to use the car this Friday evening.

Look forward to receiving advice.

Thanks,
Simon
e-mail: simon@realwatches.net or reply to post

PS: It's a 1999 "T" reg VVC - 75th Anniversary edition model
Simon S

Search some of the other threads on Head Gasket Failiure HGF and overheating problems fans etc

Wouldn't drive it anywhere until you have sorced the problem as you may do more damage to it!!

Good luck and hopefully not HGF

Rick
R P Earle

As Rick says, wouldn't be wise to drive it again until some more is known. Did you get any idea of where the steam was coming from? If it was an overheat due to the fan not operating (e.g. blown fuse) then I'd expect it to have been coming from the expansion bottle cap.

Rob's info might be useful - http://www.mgf.ultimatemg.com/group2/common_problems/hgf_pages/related_problems_overheating.htm

By the fact that it's OK while there's airflow past the radiator, it doesn't sound like HGF (touch wood...), hopefully something much simpler. Good luck!
Mike Hankin

I started briefly this morning and "white" smoke/steam was coming from the exhaust pipes....any ideas??

Is it HGF or radiator leak or something else...maybe just the fact I stupidly sat with the engine running?

Any ideas of costs for the above?

Thanks,

S
Simon S

Ah. No easy answer to that. When the ambient air is as cold as it is currently, the exhaust gases condense immediately upon hitting the cold air, so hard to say whether that indicates more moisture than usual in the exhaust gases, i.e. HGF. Getting a pressure test done would be the first step, if no leakage is evident then the overheat is more likely to be due to ineffective cooling. Check the two fuses first, there might be a 50p cure...
Mike Hankin

Another one i found with my 95 f was that the pressure cap broke gave symptoms of steam from engine bay and empty reservoir,

check the rivet is in the centre of the cap im told if not it wont work properly

also dont know if already stated but check oil for mayonaise like substance ie hgf and the other way round is there any oil in the water dont think it will be ad as its in the front of the car and my 95 still uses original rad working fine!!! but cant be sure. check the engine bay cooling fan as well as the rad fan up the front, the sensor is on the rhs of the engine bay from the boot bolted to the cover

Rick
R P Earle

Simon,

>>On examining the expansion tank today it is bone dry/empty. What should I do now?

As well as finding the cause of your overheating (fan fuse/expansion bottle cap etc.) and checking for any subsequent damage (HGF) you need also to bleed the cooling system. Once the expansion bottle has gone dry you are at risk of air pockets in the system. These can also cause an HGF.

See http://www.mgf.ultimatemg.com/group2/common_problems/hgf_pages/coolant_bleed_procedure.htm
Dave Livingstone

Hi,

Thanks for all your advice.

I've actually got the RAC on their way to check it for me....

Anything in particular I should ask him to check?

- Pressure test
- Oil
- Fuses
- Rad/Engine fan

Anything else?

Thanks.

Simon S

Simon,
Ask him if he can do a sniffer test, as they do on the MoT for gasss, a clue that could point to or away from HGF.

It must be bled thoroughly and properly as Dave says.

Upgrade the rad fan fuse to a 20amp (from 15).

Exhaust "steam" as you call it, at this time of the year is not a problem when the car is cold but you would want to see it clear up when warm.

Change the expansion tank cap, very cheap and if the system is to be drained use the better OAT coolant.

To be honest you need to ask yourself why the temp gauge got so high as, with cold ambient air especially, the engine should have been comfortable for that length of time providing the rad fan had cut in, when required and when the engine bay temperature reached it's cut-in temperature then cool air is sucked in from the O/S vent to cool the engine bay.

Adrian
Adrian Clifford

Thanks all!

The RAC have just been - no leak, not HGF thankfully, expansion cap ok - even the water temp guage is still working.....so it looks like possibly the radiator fan didn't kick in - what do you think?

Just a point - I only use my MGF once a week really and they advise starting the car every other day especially through the winter months....makes sense to me (now!)

Anyway, I'm taking it to an MG/Rover garage in the morning so will keep you all posted on the findings.....as I'm still a bit perplexed as to why out of the blue it happened.

Thanks,
Simon
Simon S

Well problem solved!!

It seems it was a faulty expansion tank cap and ECU sensor.....so no HGF...or leaks!!

PHEW!!!

Thank you all for your help and advice.

Simon
Simon S

This thread was discussed between 20/11/2005 and 21/11/2005

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