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MG MGF Technical - overheating

ok just had the engine 'redone' gasket waterpump rotor arm cam ect, but water is still bubbling in water bottle and steam coming out of back vents like an errupting volcano yet the temp gauge is pleasantly reading just below half???
m chesworth

There is a bypass feed back into the water bottle which bubbles on the LHS of the bottle if everything is OK. Steam coming out of the back vents is most likely to be evaporation when first started or a simple hose leak. Do the vents still do it when warmed up?
Charless

the steam was seriously bubbling n the water bottle like merlins potions and car inside filled up with steam, so much so that people were beeping me*shame* the cap was a new one... do you think it could be temp sensor or stat the garage has fixed all the symptoms but i think not fixed the root cause...
m chesworth

garage says its gonna look at the thermostat next *sigh*
m chesworth

It could be an airlock if the bleeding has not been performed correctly. Where does the water level settle when it has cooled down? These cars do not self bleed - a common misconception. It doesn't sound like just the temp sensor and if it was the thermostat not opening alone, the temp guage would probably have done something. It sounds like you may be right about symptom versus root cause.
Charless

ok temp gauge is sitting nicely on midway it doesnt go above that, water levels in bottle can vary when engine is cold but usually look empty to low,
m chesworth

This is sounding like a back to the garage who did the work job.
Charless

My thoughts are pipe leaks to the heater assy - not the usual ones underneath the car.

willyphixitt
W A Nixson

If the heater pipes were leaking inside the car I would exoect wet carpets, not a mobile sauna. I wonder if the geyser from the engine vents is being fed from the same source and iis somehow getting to the heater intake inside the bonnet? The steam in the header tank sounds like it isnt pressurising maybe due to a leak elsewhere, possibly onto the exhaust manifold.
Stan Best

Hi,

Have you tried changing the pressure cap on the water expansion bottle?

I had exactly the same problem, temp gauge sitting in normal position,but the water in the expansion bottle boiling like crazy and steam everywhere. At the time I found a report on the web indicating there was a problem with some caps and I think from memory the report identified that the faulty caps have a little identifying dipple in the top centre of the cap.

Anyway, mine had this identifying mark so fitted a new cap and it solved the problem. This was some years ago and the problem has never re-materialised, he says fingers crossed!!

May be worth a shot if you haven't already replaced it

Steve.
S Cotton

This thread was discussed between 13/06/2011 and 21/06/2011

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