12 replies to this topic

[sterrey]

Hi all, hope someone can help?

It first over heated just after I had purchased it (typical) - basically the expansion tank cap bubbled and fizzed and I lost approximately 2 pint of water however the Engine temperature was only tad above normal?!

I purchased a new thermostat and during replacing it I noticed that the previous owner must have over heating problems as there was no thermostat to replace. So I put the new thermostat in and left it on tick over for 10 minute, and with no surprise it over heated via the expansion tank.
I have tried RAD flush without success, so I can only assume there is a blockage somewhere.

Other notes:

- Heater does not work, neither do the pipes leading to the heater get warm
- Only over heats when sat still - not when on the move
- The fan does work and kicks in as it should
- Engine temperature on the dash does not really go above normal

Any pointers regarding the possible issue will be much appreciated – thanks

[chrisking2021]

Hi all, hope someone can help?

It first over heated just after I had purchased it (typical) - basically the expansion tank cap bubbled and fizzed and I lost approximately 2 pint of water however the Engine temperature was only tad above normal?!

I purchased a new thermostat and during replacing it I noticed that the previous owner must have over heating problems as there was no thermostat to replace. So I put the new thermostat in and left it on tick over for 10 minute, and with no surprise it over heated via the expansion tank.
I have tried RAD flush without success, so I can only assume there is a blockage somewhere.

Other notes:

- Heater does not work, neither do the pipes leading to the heater get warm
- Only over heats when sat still - not when on the move
- The fan does work and kicks in as it should
- Engine temperature on the dash does not really go above normal

Any pointers regarding the possible issue will be much appreciated – thanks

id start by changing the expansion tank cap its cheap and they are notorious for allowing engine cooling system to overheat. i have also had the water pump fail so thats another thing to check. On my mini the flange that the pully mounts to where the four bolts attach had kracked and was spining on the shaft.

if you are going to take the pump off to check it it would be worth replacing it £25 of ebay new

let us know how you get on

chris

[dwealds]

Hi, I had the same problem but without the issue of the heater pipes not getting hot. What I did as mine is a stage 4 so will run slightly hotter anyway was put a new higher capacity radiator in, a 74 degree thermostat, new expansion tank, cap and is now running on Evans NPG race coolant. She now runs sweet as a nut and hasn't overheated since I did the work.

As to the thermostat gauge not moving very much, neither did mine when it was really hot, I think that they are electric and someone said when i posted the same question up that they are as good as useless.

Good luck sorting it

[sterrey]

Great thanks for the advice, I'll start with the expansion tank cap and the Evans NPG race coolant.

I'll keep you guys up-dated

thanks

[dwealds]

I warn you now that the coolant is very expensive. If you get it don't waste it! lol

[sterrey]

Hi Guys, I replaced the expansion tank cap, which seems to have done the trick!

The noticeable difference was the top hose, it held much greater pressure when giving it a squeeze (hope that's normal), and of course no fizzing or bubbling coming from the expansion tank.

After driving it hard for 10 minutes I pulled up leaving it on tick over and waited for it to overheat, but as everything should happen the fan kicked and cooled it back down. Standard antifreeze was also added - hopefully all is fixed...

Thanks for the advice!

Alan

[sterrey]

Still running perfectly

[dwealds]

Nice one, looks like a very nice car!

[sterrey]

Hi guys, over heating back in a big way.

Took my mini round the Castle Combe take on Saturday with no problems, however.... (very short video)

When leaving to head home (4 hours after racing around) the temparture gauge was near the red all the way home, At first thought it might have been because it was a hot day etc... But again this morning took it 5 minutes down the road and the gauge shot passed the red line (Expansion chamber was fine)

I've removed the rad and flushed it out with no issues and I've also removed the water pump which also seems to be fine.

I'm going to remove all the remaining hoses this week and flush them through to double check - one note, heating in the car still doesn't work.

Any ideas, before I put it back together?

Edited by sterrey, 27 September 2009 - 06:03 PM.

[Pauly]

Do a complete engine flush first (saves flushing every single hose).

Remove bottom hose then place a hose pipe in expansion tank, turn hose pipe on full, pull the heater valve out so it flushes the heater aswell, start engine and let the engine push the water out the bottom hose, leave it running until the water is roughly clear, refit bottom hose then refill radiator/expansion tank, slowly! let any air bubbles escape, start engine with expansion cap off and heater valve still open, leave it for about 10 minutes then refit cap, may need another cap aswell seeing as it overheated again.

Failing that it might be the big HG (headgasket) if it is do a compression test first to make sure.

Paul.

Edited by Pauly, 27 September 2009 - 07:06 PM.

[sterrey]

I disconnected the inlet and outlet heater hoses in the engine bay and then attached my garden hose to the inlet. Keeping the heater valve open I turned on the garden hose to find nothing exiting. (Soaking myself in the process)

However after a couple of attempts I managed to get a trickle from the outlet and then a whole load of light brown clay textured gunk flooded out! It took about ten minutes to run totally clear. (Guess that's my heater problem fixed)

Just put everything back together and will flush the system tomorrow as advised - Thanks

[sterrey]

Flushed the system and took for a spin... within 5 minutes it over heated again?! I could only think it might be the new thermostat I put in... Sure enough it was! I know these thermostat’s aren’t the best in the world but this one only lasted a couple of weeks.
So I purchased a new one - Once fitted started the engine and the radiator started leaking. Ummmm? So, new Radiator was ordered and I’ll be fitting this weekend.

Here is my theory so far... (Please correct me if this sounds wrong)

The person who had it before me had a leaky Radiator and filled the system up with LOTS RAD weld, which did the job of sealing the Radiator but it also clogged up the heating and the old thermostat. (That’s probably why it was never replaced and ran without one).

When I put a new thermostat in, and semi flushed the system first time around - the car was fine. Well up until Castle Combe where I can only assume after going for a hard spin and then letting it cool down the thermostat was then sealed shut because of any RAD weld still in the system?

Saga continues... New radiator to be fitted this weekend (fingers crossed)

[sterrey]

All fixed and running fine Hope this thread helps someone else...