replacing thermostat

[daz]

I've just had my head, head gasket & liner shims fitted & now it seems as if the previous owner has filled the car with so much k seal the thermostat is sticking so I need to replace that now. Is there a recommended thermostat? & do I need to buy any additional o rings? I'm loosing the will to live with this car now, after a month of ownership nearly £1k in repairs & 12.7 miles I still can't use it so any advice would be great.

Thanks.

[daz]

I'm thinking of picking this one up:

http://www.eurocarparts.com/ecp/c/MG_TF ... ea5&000325

[stuart]

Sorry to hear of your woes Daz and hope all will be fixed and running beautifully soon. it sounds like you've saved this car from the previous owner and are paying the price for their neglect/bad maintenance.

Rob's site as ever is very informative on the subject:

http://www.mgf.ultimatemg.com/group2/co ... ations.htm

For what it's worth, many head gasket failures are repaired without ever getting to the route cause of the failure in the first place...the standard thermostat housing is a cheap two piece plastic part held together with brass dowels...under pressure it can come apart slightly meaning a sudden loss of coolant and...HGF.

Upgrading as per Rob's instructions will prevent any repeats- I wish you well with the repairs

[daz]

Just been out to have a look at it, there aren't any leaks. According to the mechanic the left side coolant pipe is getting hot & the right isn't (as you sit in the car) rev the car & the temperature gauge drops. I've removed the thermostat & stuck it in a pan of boiling water & it opens just as the water's about to boil, I haven't got a thermometer to check the temperature. I'll replace it anyway as it's out.

TBH at the moment I don't have the money nor the inclination to fit a PRT, I'm just sick of it all

[talkingcars]

The thermostat starts to open at around 60' and should be fully open at 88' so yours sounds slow.

[Tipper]

An 82deg stat is best for the F/TF.

[daz]

I've bought the new stat & tested it along with the old one & the new one opened and closed a bit quicker than the old one. I fitted it & the car's still the same.

As you sit in the car the left under car pipe is hot & the right is cold. The left side of the rad is hot & the right side cold. I did notice while bleeding the system though the radiator bleed screw doesn't tighten up, it's a metal screw & plastic rad, when the car gets up to temp you can see coolant bubbling out very slightly, would this cause the problem?

Is there a way of fixing this or does the radiator need replacing?

I can squeeze both pipes at the rad end & hear the coolant in the expansion tank moving.

It's a 2003 1.8 mpi by the way.

[RobboMC]

I wouldn't think you NEED a PRT, want one maybe, but plenty of 2001 model cars and earlier are still running fine without one.

Unfortunately you are going to need to keep going through the system getting rid of the blockages as you go.

The radiator may not need replacing; any decent shop can remove the header tanks, push rods through the core
and refit the header tanks. However you might find that once the core is out is may be just as economical to fit a new one.

But be sure the engine is warm enough to open the thermostat before you jump to a conclusion. But in a 13 year old car a good radiator clean won' hurt anyway.

[daz]

Hi,

The car's definitely up to temp (been left idling for 20-30 mins) I'm more concerned about the radiator bleed screw not tightening, it looks as if it's been over tightened & stripped the plastic thread in the rad.

[daz]

a further update, replaced the radiator now with a brand new one & it's still the same, the car will idle fine for 50 minutes, but once up to temp if it's driven in a "spirited" manner the temp gauge climbs to 3/4 quite quickly. I checked the radiator & pipes when the slam panel was removed & they seem to be heating up properly, no cold spots etc. I'm at a loss now.

[daz]

And another update, if anyone is still reading this

I've noticed that when the heater is set to cold even at idle the temperature gauge rises quickly & as soon as it's set back to hot it drops again and now the eml has come on & my obd reader has decided to stop working

[Mykel]

Defo a sticky ’stat. Been there, done that, a nasty job with an alloy inlet manifold, a bit easier with the plastic one. It took me 2½ months to tackle the problem, as it was in winter (on the F, standard ’stat) when it happened, I simply had the heater on full all the time which funnily is sufficient to cool the engine! Well at least in the winter.

I fitted the standard thermostat, as well I run a Land Rover PRT (tan) in the TF. No problems whatsoever and both the cars warm up pretty quick. And stay at the recommended temperature when warm.

[daz]

I've replaced the stat & still have the same issue, it still overheats whether the heater is on hot or cold, but it overheats slower when it's set to hot.

[Mykel]

Sorry, missed that bit. What about the water pump? A couple of years some were sold in the market with plastic propellers, which tended to “disintegrate” quite quickly.

[daz]

That's my next thought, I've just had a new water pump fitted when the head & liner shims where replaced. The company that did the work are coming back out to look at it, fingers crossed.

[CJLMGForum]

Hey Daz - any news on your woes?

[daz]

nope, gone away to be looked at now

[daz]

Righto, all the pipes are now heating up, but the car still overheats when the heater is set to cold. It seems to take a while for the return pipes to get hot, is this normal? The water pump is ok as are both fans.

I've done a 50 mile trip with no problems when the heater was set to warm, not hot but a short 5 mile blast with the heater set to cold & the gauge started to climb.

Am I ok to temporarily remove the stat to see if that's the issue?

[radddogg]

You can try that yes, I've done before on other cars. As long as the housing seals OK.

Have you checked the joggle valve? Could be a bleeding issue

[daz]

I've done it myself on other cars, I wanted to know if it's ok on the tf as I read somewhere it was a bad idea, I can't remember where though it's been bled so many times I've lost count