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MG TD TF 1500 - TD Overheating

Hi everyone

Just finished fitting a 5 speed Ford T9 gearbox and did the first roadtest yesterday - first time on the road since last november, just to find that the temperature goes up to 100C in the first 2-3 km and that the drain pipe of the radiator lets out steam when back home.
Expect the thermostat to be the issue as lack of water isn't. Just wonder if I should go for a new waterpump and flush the radiator at the same time?
kind regards

Torben
Torben Olesen

I would check the thermostat first.
Sandy
ss sanders

Hi Torben,

I would think about it in terms of different steps to address different causes.

If your water/coolant mixture is clean and not rust colored, you most likely do not need to flush the entire system.

If your waterpump pulley is not loose and/or making noise - it may be ok - though I have seen and repaired one on a car where the impeller had come loose from the spindle - so the pump seemed fine - but was not moving coolant.

I would remove your thermostat housing first and check that. Though it did seem to get awfully hot in a very short time span. It may be that your waterpump has failed - you can check that though when you remove your thermostat housing - just crank it up and see what it is doing - messy but easy!

Good luck.

The blocks can hold a great deal of sediment buildup and this can lead to hot running - but I think you would have noticed that last year as well.

Timing or a very lean fuel mixture could also cause some hot temps.
DLD

Make sure you get all the air out of the block before you start the motor. If you have any air in the block or head when you start it you can generate steam which will push out what water you had in there. Burp it by squeezing the radiator hoses or take off a heater hose and force water in the block or water pump.
imho
Chuck
cj schmit

Torben

I fitted a 5 speed gearbox from High Gear Engineering several years back and had absolutely no issues at all.

I would check out the possibility of air in your system per above and try again.

Rod
R D Jones

If you're letting steam out at 100 degs I'd look at the rad cap as well as the thermostat. It should pressurise the system to between 4 and 7 psi depending on the rating of the cap, in which case the temp should go up to 106-110 deg before steam comes out.

Did you have a problem before you changed the gearbox?

Are you sure there's no air in the system, do you have a heater? That could cause an air trap.

My TF had a temperature problem. I changed the thermostat, took the 'stat' out, changed the rad cap, flushed the system out twice then tried chemically cleaned it with Rad Flush, put a 7 blade MGB fan on it but nothing worked until I re-cored the rad! Now it stays at 85 degs all the time.

Oh, when I changed the rad I also put in a new pump although I think the old one was probably ok.

AJ


A R Jones

Before you go and use harsh chemicals to flush the cooling system, use ARM & HAMMER SUPER WASHING SODA !!
Mix a cup in some water and pour it into the rad,, drive around for a few days, and drain it out,,, It's an old school method of cleaning out a cooling system rather than using harmful chemicals that might hurt you old parts!

SPW
STEVE WINCZE

AJ,

The TD doesn't have a presurized cooling system, the TF does and thus has a presurized radiatorcap.

Otherwise I agree with your comments, especially the comment about recoring the radiator....
Willem van der Veer

Hi all

thank you for all your kind answers.
I'm aware that the heatingproblem hasn't got anything to do with change of the gearbox.
but I was looking forward to a nice evening cruize - the first ride since mid november, so it was a bit disapointing to expierience over 100C after less than a couple of kilometers.
I too thought of the thermostat, but I'm not quite as expierienced as most of you guys! and it never hurts to ask
rgds
Torben
Torben Olesen

I take it that the car was fine before The transmission swap. I agree with the others on the thermostat It's the most prone for the problem you described and it's the easiest thing to check. Remove it and put it in a pot of water and see what happens.

Let us know what you find?

Ed Stanfield
TD/20709
ECS Stanfield

Hi all

Two things were found when I removed the radiator tophose and the thermostat.
First thing was a piece of what looks to be maskingtape blocking about 1/3 of the thermostat. Wonder where it comes from - and how long it's been there.
Furthermore I took the thermostat to the kitchen and dumped it into a bowl with boiling water just to find that it was stuck. But after a little tapping with a small hammer it opened as supposed and everything works fine now - no overheating, so I guess only thing to do now is to hope for no more maskingtape showing up.........

rgds
Torben
Torben Olesen

Torben,
I hope you installed a NEW thermostat.. If the first one got stuck, and you freed it by a few taps, there is a darn good chance that it will get stuck again!!!

SPW
STEVE WINCZE

New one is ordered :-)

Torben
Torben Olesen

This thread was discussed between 31/03/2014 and 07/04/2014

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