:welcome:......


Few questions to consider

• are you loosing coolant?
• is the coolant 'clean' in the header tank or is their an oily film on the surface
• Might be the coolant cap....£6 to fix??

 

Thanks Lee, in answer to your questions

No coolant loss - my first suspicion!

Coolant is clean - no oil etc

Bought a new cap 'just in case'!

Very frustrating!!

 

Hi Aidi, when you first start up how long does it take to warm up on the gauge, and how long before you get warm/hot air out of the heater.

You say once it goes over 4000 rpm it blows warm when you drop below 4000 does it blow cold again,

I wonder about your thermostat being jammed open.

 

if you aren't losing coolant and the header tank is nice and clean then I doubt HGF. Sounds to me like an air lock.

Am sure more techie minded members may well suggest other things to check

Now that you've posted.....you do know :rules: :nopics:.....:rofl:

 

The thermostat being stuck open, or not being there, or drilled out would be my first guess too.

 

Hi Steve,

It takes around 5 mins for the temp guage to start to rise - bit longer at the min! Then the heaters blow cold untill I take it over 4000, then returns to cold again, this also is whats happens with the engine temp, in reverse - obviously!

Lee - please excuse the noob - I'll get my head into the rules asap - good work on the Friends round London run - good to see MG owners raising funds for the best charity there is!

 

another point that may help - when I did the 2nd bleed I noticed the coolant coming through the front 2 bleed screws was warm - although the heater bleed screw was initially cold - but the one on the pipe above the gearbox was seriously cold?

 

Have you considered a faulty water pump? If the vanes have broken or corroded the higher reves could get the coolant to circulate properly. Just a thought.

 

Hi aidi, rebleed as before, with the heater on hot but the blower not switched on, once bled feel the pipes running backwards from the radiator under the car, keep the car running at slightly raised revs until these pipes start to get warm this means the thermostat has opened, rebleed then, but if the pipes start getting slightly warmer almost straight away after the first bleed it will indicate your thermostat is open or partially open. So the car will struggle to get up to temperature.

 

Cheers for the advice guys, ended up taking it to a garage who came well recommended from my Dad, he found the pipe with the bleed screw just above the gearbox was expanding indicating a block, thought it must be the thermostat, replaced it and still exactly the same symptoms. Looks like Im gonna be motorless for a few weeks yet.......