Topic

Hello everybody got a problem with over heating ,I have already called my support worker in the H,G,F support group and bought a bottle of johnny walker black label so bring it on .
I have known my little mgtf for about four years i went halves with my son to share with his mum while his classic mini was being restored again .
The head gasket was replaced along with the head bolts and the oil rail about 3 years ago, the coolant pipes about three months ago and its been fine I bought his half a few weeks ago and I use it to go to work in and its great .
I live in Sheffield but work in Worksop and I was driving home and was held up at road works when I noticed the temp needle approaching the red,and the radiator fan running, it normally sits around the 8 o clock position if you get my meaning I stopped let her cool down while I bought a bottle of water.
Came back ,water level was ok ,and no water in the oil or oil in water, no bubbles being pumped into the expansion tank or steam from the exhaust . I got her home the temp gauge wavered a bit then went back to normal tried the heater and its cold when gauge is high and hot when gauge at normal position.
That weekend I bled the system and found air in the heater and the radiator but I did not bleed the engine .
Ran her to work the following week and shes ok going to work the needle sits at 8 o clock as normal but I start in the early hours so no traffic but going home same thing again temp needle going up as fast as a second hand on a watch and again the same symptoms.
so I bled the cooling system again with the engine cold and not running.
Left the cap off
Filled the expansion tank .
Bled the radiator.
Bled the heater.
I then tried to bleed the engine using the bleed screw in the engine bay and nothing not a drop ,ran the engine with the pressure cap on and off and nothing, I have had to get my midget out of semi retirement to get to work, so any ideas of what could be the problem would be appreciated many thanks for looking Andy

Hi Andy.
First job would be to replace the pressure relief cap on the expansion tank, a cheap and quick one to prove out.
If that fails then I would have the coolant system pressure tested to see if there are any leaks. A test kit is quite cheap off e-bay and worth having if you do a bit with the spanners...
The pressure test should prove if you have any issues with leaks or HGF. Leaks around the water pump gasket is another area to check.
If your coolant has not been changed for a while it may be worth flushing your system through and replacing the coolant and doing another bleed.

Sundance

Thanks for the reply mate ordered the cap this morning ,if I get a chance today I will run it up to temperature keeping an eye on the gauge to see if it will give me any clues of the problem

Did you say the radiator fan was running?

Last time my temerature gauge went into the red in traffic the rad fan fuse had blown. Sadly this must have damaged the gasket because a few weeks later I had oil in my coolant bottle.

Check the fuse its under the bonnet.

if you are still running on the original radiator it might be worth checking the integrity of the cooling fins. They could be blocked or more likely non existent across a large area of the rad. If you are overheating only when stationary it would point to the system not being able to remove the heat without the normal forward motion of the car.
If you put the heater on full with the fan also on speed 4 whilst stationary does it bring the gauge down closer to normal?
Nigel

Thanks everybody for your help with this I have had a bit of a tinker and bled the system again and theirs been a development .I bled the rad and heater all OK .
I then bled the engine bay and again bone dry, left it running and the pipe with the bleed screw attached was cold switched off and let the pressure drop and had a poke about down the hole and it was blocked by sealant of some sort and the screwdriver came out dry.
Took the cap off and then coolant then flowed out of the bleed screw hole.and the pipe became warm obvious airlock.
l Left it ticking over for more than 30 minutes and she kept her cool the needle stayed at 8 o clock let it cool and bled her again all ok took her for a spin came back left her ticking over temp needle still at 8 o clock and all the pipes hot .
So tomorrow shes on her usual duty of ferrying me to Worksop and I will see how she goes.
One thing though should the bleed screw be a nipple like the one for the heater because mine is a fanged bolt with no form of gasket?could this be the cause of the air getting in overtime ? I put a temporary one on, thanks for looking and your help Andy

Good news!
Yes, that bleed is normally just a bolt. No gasket. Nothing to prevent you replacing with a bleed screw and gasket.

Often people have the 'no bleed' blockage on the heater matrix too. Same solution.

Hello again ,no I've not gone away still got the overheating problem I parked the TF up while I had a think and did some other stuff,mainly replacing the front wishbone bushes on my sons 2009 mini cooper what an utter,utter Bxstxxd forced to take the front of the car off, drop the engine, sub frame to get at the anti roll bar bolts, you can't get at them because the car body is in the way give me an dodgy head gasket any day .
Anyway back to the job in hand ,
the last time I used the car I fitted a new expansion tank cap and that made things worse,I got to work ok but on the way home I got to the end of our road and it boiled, pushing coolant out of the tank, so after parking her up I topped up the coolant and this Sunday I did this :-

After being parked for a fortnight no loss of coolant no air pockets.

started her and left her ticking over for about 20 minutes with the cap OFF got to temp ok level rose but nothing extreme noticed a few bubbles in the stream of coolant but not many and not large.
Let everything cool down coolant returned to normal level ,no air pockets .

Put the pressure cap on left her ticking over got to temp and the coolant expanded and nearly filled the bottle ,then the level dropped quite quickly to about the normal hot level , the temp maintained its ok reading i left her ticking over for about 10 minutes longer the level rose again this time blowing coolant out of the pressure cap I switched off.
I did still notice bubbles coming into the tank from the pipe into the tank as the end became submerged, still small and at irregular intervals but there all the time the engine was running .

let the car cool no air pockets and the level returned to normal .

There is also a noise when I switch the ignition on or off that can only be described as someone sucking on a lemon or orange it does it with the cap on or off .

The car has been left more than 30 odd hours with no loss of coolant and no air pockets .
Thanks for your help and trying to help me out, it is appreciated Andy.

If the fans are working and you have no air in the system then it does sound as if you have a exhaust gas leak into the coolant. ie HGF.

You need to get a 'sniff' test done. Any garage should be able to do it. Tells whether there are combustion gases in the coolant.

Where did the new cap come from? It isn't uncommon for pattern ones to be faulty from new.

Ande wrote: wrote:

.....There is also a noise when I switch the ignition on or off that can only be described as someone sucking on a lemon or orange it does it with the cap on or off....

Do you have an induction system fitted?
I have a K&N Apollo fitted and it does this.

Hello its been awhile but I've had one hell of a busy summer and the little TF has had to take a back seat but now I need her back on the road .
First of all let me say thank you to all that have helped me with this problem, so where are we.
I used one of those test kits from Ebay were the liquid goes from blue to yellow when it detects fumes and of course it went yellow
Head Gasket failure confirmed when I took it to bits and it had blown between the exhaust and number one cylinder.
The multi layered gasket had blown between the layers around number one and the rest of it was not in great shape ether.
Now this may sound bad until I tell you when I tell you that when I took the cam belt off a bolt holding the inner cam cover on had come adrift and cut through the timing belt leaving holes in the troughs of the belt and the inner cover has gone brittle and fell apart,maybe due to the heat as it rubbed the cam sprocket and belt,so I think i dodged a bullet there.
so gentlemen can I have your thoughts on the following please,

I have cleaned the head and checked for any warp by using a good straight edge and a super bright torch, corner to corner .length ways ,across and between everything and all seems good ,Is this test good enough?

The replacement head gasket , I intend to replace it with the N type gasket with new bolts from MG Rover spares the TF already has the updated oil rail,is this type better than the multilayered gasket? which I have to say was coming apart when I took it off.

when I took the cam sprockets off I forgot to notice how they were mounted am I right in thinking that the split pin fits in the groove marked 'in' and 'ext' ?

I suspect the failure was caused by a faulty pressure cap I think this because the symptoms changed when I got a new cap all be it too late am I right in this thinking ?
anyway thanks for looking and any thoughts are appreciated Andy

There has been some good feed back on the N series gasket.