thermostat broken - how easy to change and is it Mr T only ?

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raptor95GTS
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thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

hi folks, my thermostat has given up the ghost and now the engine temp is right down at the bottom of the scale. How easy is it to change it and can I get thermostat from halfords or do I rally need to lube up for mr T?
Rogue
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by Rogue »

Hi Allan,

There are plenty of generic thermostats available (even an uprated TRD one!), so it doesn't have to be a genuine Toyota part.

The thermostat housing is only secured by two bolts, but one of these is extremely difficult to reach with the engine in the car! I'm not suggesting it's an engine out job, just that you'll need spider-monkey hands, some good tools and a lot of patience.

Be aware that the temperature gauge sender could also be the cause of the fault. If you've changed the thermostat and the fault persists then get back in touch with me and I'll give you the part number.

Rogue
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

cheers rogue, I'll have a look on sunday and see if I can get to both bolts. I reckon the sender is fine since the heater blows out lukewarm air so its not getting warm water either. The car feels pish as well so I'm pretty certain its the thermostat
Jayng

Re: thermostat broken - how easy to change and is it Mr T only ?

Post by Jayng »

Changed a thermostat last week on a Rev3 tubby that I bought for a customer.

It`s not that difficult to swap over. Intercooler side of the engine bay. You can`t miss it as there is a big coolant hose going to the block. You might have to remove the stay bolt for the dipstick if you want better access. Just used standard 3/4 inch socket set.

Hope this helps.
raptor95GTS
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

hi jayng, yeah I saw from the old BGB that the dipstick might have to be removed and my heart sank cause the seal if going to be a mr T item. I'll have a look tomorrow at the car and see if I can get spanners / sockets in and if so I'll have a go at changing the darned thing myself.

Better get a large bucket to catch all that coolant :(
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by BenF »

allan welsh wrote:hi jayng, yeah I saw from the old BGB that the dipstick might have to be removed and my heart sank cause the seal if going to be a mr T item. I'll have a look tomorrow at the car and see if I can get spanners / sockets in and if so I'll have a go at changing the darned thing myself.

Better get a large bucket to catch all that coolant :(


Allan, FWIW I'd reccommend against a Blueprint part - a number of people have had problems with Blueprint parts, and I doubt a theormostat would be much more expensive from Mr T.

One other thing - when fitting it check you've got to get the orientation spot on so it can open/close correctly - there's some stuff in the BGB about all of this.
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

yeah I've looked at the old BGB and saw the 5deg tolerance lol. I'll need to get a new seal for the oil dipstick guide as well and that will defo be a mr T part.

Seriously considering getting the garage to do it as I can't be ar$ed working outside when its snowing outside FFS
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by Edwin »

I've got two used Toyota thermostats in very good condition around from a Rev3 Turbo if you're interested...

Image
raptor95GTS
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

thanks for the offer edwin but for the price difference in new parts I'd rather just stick with a new one. Thanks for the offer though

edit - just had a look and my thoughts are s0d that! I could likely get the housing off but I'm not confident about getting it back on as I don't really have the right open ended spanners

Any mechanics within 100 miles of glasgow want to fit a new thermostat for me? Few beers in it for ya :lol:
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by CJ B »

Hi Allan,
Sorry if this is waaay too daft but have you checked your coolant level?
Even without a thermostat your engine will warm up to temperature but at a slower rate.
Unfotunately this is the time of year when cars freeze up & if anyone did a bit of maintanace and dropped the fluid in summer thinking 'I'll put antifreeze (for life etc.) later on' and then forgot.... (I usually fall into this category :S)
If an engine freezes its normally core plugs and water pump that fail, occasionally cylinder head :(
I hope this DOESNT help you,
Cheers & Merry Christmas,
Chris.
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by jimGTS »

i had a garage do my thermostat.
ive a rev2 tubby, and the bottom bolt as stated, is a right bu88er to get to!! i ended up cutting my hands to bits trying to do it. after i cleaned all the blood up, lol, i decided it would be best to take it to a garge.

BUT, it turns out, my temp sender also went, so had to replace that also. easy job!
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

CJB wrote:Hi Allan,
Sorry if this is waaay too daft but have you checked your coolant level?
Even without a thermostat your engine will warm up to temperature but at a slower rate.
Unfotunately this is the time of year when cars freeze up & if anyone did a bit of maintanace and dropped the fluid in summer thinking 'I'll put antifreeze (for life etc.) later on' and then forgot.... (I usually fall into this category :S)
If an engine freezes its normally core plugs and water pump that fail, occasionally cylinder head :(
I hope this DOESNT help you,
Cheers & Merry Christmas,
Chris.


lol CJB I thought exactly the same thing - have I dumped a load of coolant somewhere?

I have checked the coolant level and its up to the pressure cap no problem, the expansion bottle is half full and the pipes coming out from the engine block are hot to the touch and have the feel of water inside them so its defo the thermostat - thankfully

jimgts - as soon as I looked at the housing with the nuts on the studs I thought no way hose am I doing that. Kerching for a garage / mechanic somewhere
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by reggie »

If the engine water hoses are up to temperature and your temp gauge on the dashboard shows the right temperature and your heater is kicking out less than hot air, this doesn't indicate a thermostat problem. It is more likely that there is a problem with your heating matrix.
The thermostat simply allows the coolant to travel to the radiator when the engine is getting too hot to prevent it from overheating. If this is gone, you will either have a problem in that your engine takes too long to warm up (failed open) or your engine overheats (failed closed).
I'm not familiar with the Mk2 engine but I would suggest that you do not remove any oil seals (including dipsticks) at the same time as replacing your thermostat. This is because when you break the seal in the thermostat housing, some coolant will drain out and you do not want any of that coolant to get into the oil. If it does, you will have a much bigger job on your hands when the big end bearings go and you need a complete top end engine rebuild. If there is no way of the coolant getting into the oil then please ignore this para.
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by BenF »

allan welsh wrote:

I have checked the coolant level and its up to the pressure cap no problem, the expansion bottle is half full and the pipes coming out from the engine block are hot to the touch and have the feel of water inside them so its defo the thermostat - thankfully

jimgts - as soon as I looked at the housing with the nuts on the studs I thought no way hose am I doing that. Kerching for a garage / mechanic somewhere


Allan, before you do that - does the gauge move at all from the bottom of the dial? If it doesn't move at all, but the pipes going to the front of the car are hot and you get hot air from the heater matrix, I suspect all that's wrong is that the sensor wire has come off the water temperature sensor - the tab could have corroded off itself.

There are two water temp sensors - the first is to left of the dizzy cap and had a green plug - that's the ECU temperatures sensor. There's another temp sensor in that area too - a little smaller, possibly with a yellow plug (?) - that's the one from the dash. Just check its all plugged in and OK ..
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by jimGTS »

BenF wrote:
allan welsh wrote:

I have checked the coolant level and its up to the pressure cap no problem, the expansion bottle is half full and the pipes coming out from the engine block are hot to the touch and have the feel of water inside them so its defo the thermostat - thankfully

jimgts - as soon as I looked at the housing with the nuts on the studs I thought no way hose am I doing that. Kerching for a garage / mechanic somewhere


Allan, before you do that - does the gauge move at all from the bottom of the dial? If it doesn't move at all, but the pipes going to the front of the car are hot and you get hot air from the heater matrix, I suspect all that's wrong is that the sensor wire has come off the water temperature sensor - the tab could have corroded off itself.

There are two water temp sensors - the first is to left of the dizzy cap and had a green plug - that's the ECU temperatures sensor. There's another temp sensor in that area too - a little smaller, possibly with a yellow plug (?) - that's the one from the dash. Just check its all plugged in and OK ..



the sensor for the temp guage is BLUE, i know, cause ive had to change my temp sendor.
mines a rev2 tubby.
sorry if there are yellow ones, but mine is blue mate.
HTH,

jim
raptor95GTS
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

BenF wrote:
allan welsh wrote:

I have checked the coolant level and its up to the pressure cap no problem, the expansion bottle is half full and the pipes coming out from the engine block are hot to the touch and have the feel of water inside them so its defo the thermostat - thankfully

jimgts - as soon as I looked at the housing with the nuts on the studs I thought no way hose am I doing that. Kerching for a garage / mechanic somewhere


Allan, before you do that - does the gauge move at all from the bottom of the dial? If it doesn't move at all, but the pipes going to the front of the car are hot and you get hot air from the heater matrix, I suspect all that's wrong is that the sensor wire has come off the water temperature sensor - the tab could have corroded off itself.

There are two water temp sensors - the first is to left of the dizzy cap and had a green plug - that's the ECU temperatures sensor. There's another temp sensor in that area too - a little smaller, possibly with a yellow plug (?) - that's the one from the dash. Just check its all plugged in and OK ..


the gauge does move but at 60mph the coolant does not heat up gauge goes to like 7 oclock but in traffic it heats up to normal 9 oclock position but takes like forever.

The coolant pipes from the engine block do get hot but that's as much heatsoak as anything else. The car feels really groggy and unresponsive much like a cold engine

The heater does give lukewarm air out but its certainly not hot. All of this leads me to the thermostat as the problem
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by ^Trickster^ »

If your engine is not up to temperature, your idle will be high as the IAC valve works from the coolant temperature. Also the ecu will alter your timing if it thinks your hammering the car when its cold, this is what will make it feel groggy.

Never buy a lower temperature thermostat either, this causes the same problems as above, people think a lower temperature engine is better but this is untrue. The engine has a cooling system designed to keep the cylinders at a certain tempertue to make the optimal burn and also for optimal lubrication of the engine as the cooler the water the colder the oil temperature will be and a slight change from what its designed at will make all the difference resulting in more wear than neccesary, otherwise why would they fit thermostats!

People all over the world are making 500bhp+ with the stock cooling system.

Graeme
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Re: thermostat broken - how easy to change and is it Mr T only ?

Post by raptor95GTS »

I don't hammer the car in fact I've been driving really carefully as the engine is dumping a HUGE amount of fuel cause it thinks the engine is cold. I value the mechanical bits of the engine / turbo too much and the fact I can't afford to fix it if it goes wrong means I'm babying the engine as much as possible.

I know the thermostat is there for a reason and that's why I want it fixed sooner rather than later. Plus is fecking cold up here this time of year and the heater dont work to well if the coolant's cold :( Hence the waiting on mr T as benf has already mentioned some problems with pattern parts.
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