Thermostat

[illgryphon]

Ok, basically I have read how to change you cars thermostat and it seems relatively simple to do.

However after you have installed the new thermostat and put the rad top hose back on, all the guides say to simply top up any coolant lost through taking the rad hose off in the first place. Is it really that simple? I thought taking the rad top hose off would get too much air in the cooling system and it would have to be completly drained and filled? An airlock kinda thing?

[CorollaD4D]

this may be counter-productive but your cars thermostat shouldn't need changing? the toyota ones hardly ever go wrong? or is it a case of prevention is better than cure with this?

[msprince]

Its ok to top the coolant in the expansion tank (the platic bottle behind the radiator) but taking the metal cap off could cause de-pressurisation and a cause airlock.

[acetip]

Ok, basically I have read how to change you cars thermostat and it seems relatively simple to do.

However after you have installed the new thermostat and put the rad top hose back on, all the guides say to simply top up any coolant lost through taking the rad hose off in the first place. Is it really that simple? I thought taking the rad top hose off would get too much air in the cooling system and it would have to be completly drained and filled? An airlock kinda thing?

when you refill the expansion tank there no need to fill it to the max mark at first.pour the coolant in then squeeze the rad hoses to help expell any air.then start engine,with cap off,the coolant level may or may not drop further.depending what air in system.if it does not drop any further.then top up to max mark.then take for short run

then check level again.when pouring in coolant do it nice and slow this reduces chances of air locks

[Uber_Luke]

I Think the reason for removal would be to fit this

awesome

and this

double awesome

make sure you squeeze both of the coolant hoses on each side of the Rad, you can tell when it stops pumping air and is just pumping coolant.

Make sure you top up the coolant with the same colour coolant - pink/red

Jealous of you if you have got the low temp therm

[nrgizerbunny]

just so we don't get it wrong.

You fill the coolant through the radiator cap! NOT the expansion bottle. If you refil through the expansion bottle you will cause an airlock in the tube between it and the radiator pressure valve.

The basic principle is when the coolant gets hot, the PSV lifts and it sends excess fluid into the expansion bottle. Once cool, the psv seats and the fluid is drawn back the other way.

There are only two problems with this. The corolla coolant bottle is moulded into the fan housing so you can't elevate it to get rid of the airlock in the short tube between the rad cap and the bottle itself. The only way I could do it is to blow on the overflow tube until there was coolant coming out of the rad cap (the rad cap was off).

[rallyfan1986]

any chance you could give me a quick guide on how to change the thermostat?

where its located, how to remove it that sorta thing, as im sure mine is broken.

Thanks

[nrgizerbunny]

i'd be amazed if it breaks. They usually fail open so your car will take ages to get warm. what are the symptoms?

[Uber_Luke]

Im sure they are made so if they fail they fail open. Otherwise it would really damage your engine if it fails shut.

Obv not wanting to hijack this thread, but what are your symptoms?? to make you think its broken

[acetip]

I Think the reason for removal would be to fit this

awesome

and this

double awesome

make sure you squeeze both of the coolant hoses on each side of the Rad, you can tell when it stops pumping air and is just pumping coolant.

Make sure you top up the coolant with the same colour coolant - pink/red

Jealous of you if you have got the low temp therm

cant get my head around claim that running engine at cooler temp will increase performance.each engine has a optimum running temp,that the engine manufacturer will try to match with the correct thermostat.sounds to me like another sales gimmick.

look at the price they are charging.as most stats are a standered size,(at least use to be) you can go to most motor factors and buy any opening temp stat over the counter.

for competition motoring then a earlier opening stat for safety reasons may be an advantage.

otherwise dont be sucked in by these con merchants.

[rallyfan1986]

i'd be amazed if it breaks. They usually fail open so your car will take ages to get warm. what are the symptoms?

Im sure they are made so if they fail they fail open. Otherwise it would really damage your engine if it fails shut.

Obv not wanting to hijack this thread, but what are your symptoms?? to make you think its broken

Car works fine in warm weather (anything above 10degrees C), keeps a constant 80degrees ish.

but in cold weather (below 10degrees roughly) it wont get past 70 degrees C, and in freezing weather it wont even engage lift (because the temp is below 60 degrees C)

This is after a 45mile drive on motorways and on country roads, so should be plenty of time to heat up.

Sorry for hijacking your thread mate

[nrgizerbunny]

that does sound like a broken thermostat.

What happens when you turn the cabin heater on? is that cold or hot

[illgryphon]

Aight so i top it up via rad cap, which is fair enough because I am going to slap a new trd rad cap on anyway.

Is the expansion tank the white thing at the side of the radiator with the fill level on it?

Thanks again for the MAF btw, 158 miles and no christmas tree lights lol!

[rallyfan1986]

that does sound like a broken thermostat.

What happens when you turn the cabin heater on? is that cold or hot

it drifts between warm and cold when the outside temperature is cold

fine when the outside temperature is warm

[rallyfan1986]

Hi,

Got myself a new thermostat,

Where is it located on the car so I can change it? I followed the hose off the radiator, but it seems to disappear into the engine.

Do I need to be under the car to change it?

Cheers

[richard.c]

Hi,

Got myself a new thermostat,

Where is it located on the car so I can change it? I followed the hose off the radiator, but it seems to disappear into the engine.

Do I need to be under the car to change it?

Cheers

Hi,

Not seen the 1.8 engine, but just follow the radiatior top hose back to where it comes out of the engine block, there will be a domed appearance to it where the thermostat is housed, usually fastened with 2 or 3 bolts - do not overtighten them , they only need 7ft/lbs torque on the 1.6 engine.

[molveees]

Hi,

Got myself a new thermostat,

Where is it located on the car so I can change it? I followed the hose off the radiator, but it seems to disappear into the engine.

Do I need to be under the car to change it?

Cheers

No you donot need to be under the car when changing it. All done while standing on your feet. the serpentine belt needs to come off, then the alternaor. Fairly simple unless you have corroded bolts that hold the alternator. once the alternator is out of the way you will be able to see the black hose pipe to the right of where the alternator was, with a bevel-ended metal part mounted on to the engine block via 2 nuts. they are small size (9 or 10mm hex nuts) & you will require deep socket set for those. the thermostat sits right behind the bevel-end. you may have to give the pipework a tug as the gasket may be perfectly sealed. be sure to change the gasket/oring at the same time & if your ribbed (serpentine) belt for the alternator is showing cracks its a good time to do that too. fill it up via the rad-cap as the expansion tank can be deceiving. you will have to regularly topup in the beginning but ultimately all air locks are driven out.

GoodLuck.

by the way TRD thermostats are good if your are running the engine constantly at high rpm or you are doing a lot of idling/local driving. other than that you do realise that this causes more wear to the engine if driven at contant speeds over long periods, ie motorway miles. i tend to stick to standard Toyota 82c TS that does the job perfectly.

[rallyfan1986]

Hi,

Got myself a new thermostat,

Where is it located on the car so I can change it? I followed the hose off the radiator, but it seems to disappear into the engine.

Do I need to be under the car to change it?

Cheers

No you donot need to be under the car when changing it. All done while standing on your feet. the serpentine belt needs to come off, then the alternaor. Fairly simple unless you have corroded bolts that hold the alternator. once the alternator is out of the way you will be able to see the black hose pipe to the right of where the alternator was, with a bevel-ended metal part mounted on to the engine block via 2 nuts. they are small size (9 or 10mm hex nuts) & you will require deep socket set for those. the thermostat sits right behind the bevel-end. you may have to give the pipework a tug as the gasket may be perfectly sealed. be sure to change the gasket/oring at the same time & if your ribbed (serpentine) belt for the alternator is showing cracks its a good time to do that too. fill it up via the rad-cap as the expansion tank can be deceiving. you will have to regularly topup in the beginning but ultimately all air locks are driven out.

GoodLuck.

by the way TRD thermostats are good if your are running the engine constantly at high rpm or you are doing a lot of idling/local driving. other than that you do realise that this causes more wear to the engine if driven at contant speeds over long periods, ie motorway miles. i tend to stick to standard Toyota 82c TS that does the job perfectly.

Thanks for the detailed reply.

Got a thermostat from eurocarparts, hopefully will be just as good as the toyota ones as I do 100 motorway miles a day.

Going to call toyota tomorrow to order the alternator belt, gasket and 5 litres of coolant - may as well change all the coolant as its nearing 80,000 miles.

Also got an oil leak to look for, its going to be a busy day!

[rallyfan1986]

Got the thermostat changed - the seal on the back had half come off, stopping it closing properly.

It was an ***** of a job to change - the bolts on the alternator were so tight, and slackening the belt tensioner wasn't easy - now have a banana shaped spanner

[molveees]

Got the thermostat changed - the seal on the back had half come off, stopping it closing properly.

It was an ***** of a job to change - the bolts on the alternator were so tight, and slackening the belt tensioner wasn't easy - now have a banana shaped spanner

Good one mate. a metre long breaker bar would have done the job nicely. what did you use for refilling the coolant system. i presfer the long life pink coolant. bit expensive but lasts a while.

[rallyfan1986]

I used a breaker bar with the handle from the jack over the end to undo the alternator, couldn't use the breaker bar for the tensioner as there wasnt enough room to pull it forwards to reduce the tension enough.

yeh I used the pink stuff from toyota, £30 for 5 litres, not cheap but is probably the best stuff to use