Correct Thermostat Operating Temperature

[Mybowlcut]

Hey.

 

My temp gauge is getting to 3/4 in hot weather and I'm a bit worried hence I am trying to keep it at half way. I've cleaned out my heater hoses, replaced the water pump, thermostat housing, thermostat, temperature sender and installed a brand new radiator. I went to a radiator conditioning place and the guy suggested to buy a lower temp thermostat. So I bought a 160 Fahrenheit one.

 

Will this affect cold starts in a substantial way? Ie will it subject the engine to more wear and tear in the morning? Is having it open at 160 instead of 180 a bad thing?

 

If it is, my only other option is to get a thermo fan installed, which is a lot more costly than a $10 thermostat. :P

 

Also, I've asked a few people but forget... should the coolant reservoir be partially full? The radiator guy said that it gets full when the coolant gets hot and increases in pressure, but mine is always empty I'm pretty sure.

 

Cheers.

 

Edit: I also searched the forums before I posted this and just read this article on thermostat operating temperatures and it said a lower temp thermostat CAN cause cylinder wear... opinions

Edited January 6, 2009 by Mybowlcut

[Croc]

Hi are you sure your temp gauge is reading correctly. Could be the wrong or faulty sender. My factory gauge has the needle in the high are, where my aftermarket shows it as 82-86c.

Cheers

[Mybowlcut]

Hi are you sure your temp gauge is reading correctly. Could be the wrong or faulty sender. My factory gauge has the needle in the high are, where my aftermarket shows it as 82-86c.

Cheers

I'm pretty sure that it's the right one. I bought one and put it in and it wouldn't even register... this one has worked (what I think is well) so far. I have no idea where 82-86 would read on the gauge haha.. where would it be?

[greenmac80]

got a thermo fan?

this could help!!

oh and the 82 mark should be halfway ish.

temp guages are funny things mine worked fine until i got a new sender which was meant for the year n stuff

but it read 3/4 hot all the time!

and this was wrong cos i could get out and sit my hand on the rad. so yeah!!

probs nothing wrong.

 

oh also i had my thermfan set to 60degrees. and the guage was at 3/4 before the thermo kicked in so yeah!!

guages are funny things.

hook up an aftermarket one!!

[Croc]

I would expect that it would be around the 1/4 mark.

Having a lower thermostat will let you coolant flow through the the whole system earlier than normal. I wouldn't expect it to change the high reading you are getting if your old one is working correctly.

do you have a fan shroud fitted to your radiator as this will help dirrect the air correctly to aid in cooling.

[Philbo]

Also check your viscous fan coupling is working. Get your motor to normal operating temperature and then turn it off. The radiator fan should be resistant to spinning by hand. If it's rooted it'll just spin freely.

[Mybowlcut]

got a thermo fan?

this could help!!

oh and the 82 mark should be halfway ish.

temp guages are funny things mine worked fine until i got a new sender which was meant for the year n stuff

but it read 3/4 hot all the time!

and this was wrong cos i could get out and sit my hand on the rad. so yeah!!

probs nothing wrong.

 

oh also i had my thermfan set to 60degrees. and the guage was at 3/4 before the thermo kicked in so yeah!!

guages are funny things.

hook up an aftermarket one!!

Yeah I have a thermo fan but like I said in my post, it will cost a bit of money to get all the parts for it and to get it wired up as I don't know how.

 

I wanna keep the original Toyota dash in one piece and I'm not a fan of stray gauges. If my car was in a bit worse condition inside and out I'd happily do it though. :y:

I would expect that it would be around the 1/4 mark.

Having a lower thermostat will let you coolant flow through the the whole system earlier than normal. I wouldn't expect it to change the high reading you are getting if your old one is working correctly.

do you have a fan shroud fitted to your radiator as this will help dirrect the air correctly to aid in cooling.

Do you mean yours sits around the 1/4 mark? What is the normal reading for KE70s?

 

But if my old one was working correctly but not opening early enough, then wouldn't an earlier-opening thermostat reduce the temperature of the engine?

 

Yep got the fan shroud fitted.

 

Also check your viscous fan coupling is working. Get your motor to normal operating temperature and then turn it off. The radiator fan should be resistant to spinning by hand. If it's rooted it'll just spin freely.

I'll check that now, thanks.

[LittleRedSpirit]

Yeah I have a thermo fan but like I said in my post, it will cost a bit of money to get all the parts for it and to get it wired up as I don't know how.

 

I wanna keep the original Toyota dash in one piece and I'm not a fan of stray gauges. If my car was in a bit worse condition inside and out I'd happily do it though. :y:

Do you mean yours sits around the 1/4 mark? What is the normal reading for KE70s?

 

But if my old one was working correctly but not opening early enough, then wouldn't an earlier-opening thermostat reduce the temperature of the engine?

 

Yep got the fan shroud fitted.

 

I'll check that now, thanks.

 

 

You're kidding aren't you. I think that knowing what temperature your engine is running at is a little more important than having the dash as intended by Toyota. Haven't you noticed the dash is 100 percent ugly as sin?

 

Anyhow, a 20+ year old gauge is far from accurate, no matter who made it, especially if its bounced around, heated up, cooled down and frozen on the odd occasion throughout its 250000klm plus life. Install an aftermarket gauge and sender to suit, and you will find out the exact temperature with a degree or two error. All this bs about half or 3/4 is pretty ridiculous.

[Mybowlcut]

You're kidding aren't you. I think that knowing what temperature your engine is running at is a little more important than having the dash as intended by Toyota. Haven't you noticed the dash is 100 percent ugly as sin?

 

Anyhow, a 20+ year old gauge is far from accurate, no matter who made it, especially if its bounced around, heated up, cooled down and frozen on the odd occasion throughout its 250000klm plus life. Install an aftermarket gauge and sender to suit, and you will find out the exact temperature with a degree or two error. All this bs about half or 3/4 is pretty ridiculous.

:y: Nah, I wasn't kidding. Personally, I like ke70 interiors (that are in good condition) that are original without aftermarket gauges plastered all over the place. If the car is a bit rough around the edges then it's probably been treated as such, and in that case, who cares?

 

Up until now, no one has said that it is impossible to get a 27 year old gauge to read correctly. So are you saying that regardless of whether or not I install a lower temp thermostat, the gauge will still be wrong? If that's the case, I'll install an aftermarket gauge as I DO want to know what temperature my car is running at and it IS more important than having an original dash. :y: I do prefer practicality over looks with cars. Installing an aftermarket gauge because the original one doesn't work is practical. But, I think nice kesevs that have them put in for "looks" is ugly as sin. I just reckon it looks riced up and hence why I was hesitant to put one in.

 

I also didn't know it could succumb to that kind of wear... I thought it would last as long as the shell. :D

 

What kind of aftermarket sender? I just went to some generic auto parts store.

 

Cheers.

Edited January 6, 2009 by Mybowlcut

[Croc]

You may be able to take it to a auto electrican to check gauge and sender.

Someone else may be able to varify this, as i think i read this on here sometime before.

[Falken_KE30]

Mine never goes over 1/4, even after a good thrash.

[Mybowlcut]

You may be able to take it to a auto electrican to check gauge and sender.

Someone else may be able to varify this, as i think i read this on here sometime before.

Yeah I think the radiator guy said that. Might go down to my local guy.

 

 

Mine never goes over 1/4, even after a good thrash.

That was the case with my last ke70.. it allllways stayed at 1/4.

[LittleRedSpirit]

Yeah I think the radiator guy said that. Might go down to my local guy.

 

 

That was the case with my last ke70.. it allllways stayed at 1/4.

 

 

You need a sender the same brand as the gauge you are buying. You should be able to get a speco 2 inch gauge, with sender and mounting bits for under 50 dollars. Do not under any circumstances put any faith in the standard gauges after all these years. Even with a radiator chocked full of grass seed after half an hour in the paddock, my old beige paddock ke never gets over 3/4, which is a bit worrying.

 

You don't have to have a 10 inch monster temp gauge with flashing neons if your worried about rice, just low mount a small one and you will have the info required. I dare say you will realise that you have no cooling issues at all.

[Raven]

IF you want to stay with the original gauge, take it to an automotive instrument servicing place over your way and get them to test and/or repair the gauge.

[dfunkt]

1- buy aftermarket temp sender and gauge.

2- install sender and hook gauge up

3- don't mount gauge (if worried about ruining ke70 interior)

4- go for drive, make note of where the stock gauge is when aftermarket one reaches 60/70/80/90/100 degrees)

5- if car is actually overheating, take to mechanic and have him fix.

6- if satisfied car isn't overheating, remove all aftermarket stuff

7- ......

8- PROFIT

 

cheers

dF

Edited January 7, 2009 by dfunkt