MR2 overheating

[the jetnz]

OK, I had the cooling system flushed etc. still over heating. Then had the thermostat looked at....replaced the thermostat....
No overheating however, the temperature gauge takes a lot longer to get to normal temperature which is just below halfway....AND during the normal course of driving the gauge drops down to about one quarter, then goes back up again?????
Can anyone explain?
Do I need to be worried??
Cheers
Will

[Dell'Orto]

AW or SW, NA, Supercharged or Turbo?

[Monsterbishi]

OK, I had the cooling system flushed etc. still over heating. Then had the thermostat looked at....replaced the thermostat....
No overheating :D however, the temperature gauge takes a lot longer to get to normal temperature which is just below halfway....AND during the normal course of driving the gauge drops down to about one quarter, then goes back up again?????
Can anyone explain?
Do I need to be worried??
Cheers
Will

definately sounds like the new thermostat is seized open, any chance you installed it back to front, or put the wrong thermostat in?

[the jetnz]

I didn't replace the thermostat myself so don't know whether the rigght one was used or whether it was put in the right way.....
Will it be ok to leave it as is???

[Monsterbishi]

I didn't replace the thermostat myself so don't know whether the rigght one was used or whether it was put in the right way.....
Will it be ok to leave it as is???

I wouldn't take the chance, the engine is designed to be run at a constant temperature, the vary temp will also affect fuelling as well, since the car will be cooling down the ecu will switch back to its cold start/run parameters.

I'd take it to another garage, get them to put another tstat in, make sure you get the other one back from them, if it's the wrong one, or more likely siezed open - take it back to the first garage and demand a refund.

[MrBob]

however, the temperature gauge takes a lot longer to get to normal temperature which is just below halfway....AND during the normal course of driving the gauge drops down to about one quarter, then goes back up again?????
Can anyone explain?
Do I need to be worried??
Cheers
Will

wouldnt be too concerned. Ive found that in these nice cold conditions (winter), that the temp will often drop around the 1/4 mark on my mr2 and corolla, especially if driving at constant speeds for a while... both my thermostats are new, and installed correctly aswell.

Obviously, in cold weather it can take longer to reach normal opperation temperature.

[the jetnz]

Thanks for your advice guys...I will be keeping a close eye on it...
The car seems to be running sweeter now that the cooling system has been flushed and thermostat replaced...
Cheers.

[the jetnz]

OK, I am still concerned about the fluctuation in the temperature gauge which goes from halfway to quarterway especially when I push the car harder than normal. It eventually goes back to halfway (normal range)
The car is driving fine at the moment and the overheating is a thing of the past...
I want to sort this out as I have a person potentially interested in buying the car (which is advertised on MR2 ORG NZ)
Cheers

[MrBob]

OK, I am still concerned about the fluctuation in the temperature gauge which goes from halfway to quarterway especially when I push the car harder than normal. It eventually goes back to halfway (normal range)
The car is driving fine at the moment and the overheating is a thing of the past...
I want to sort this out as I have a person potentially interested in buying the car (which is advertised on MR2 ORG NZ)
Cheers

seriously dont worry about it. It sounds like your temp is still within the normal range. I have had my temp gauge drop to 'C' when travelling at very high speed in winter, ie: very cold air being forced past radiator at very high speed. Yours is staying between 1/4 and 1/2 which I think is around 65-86 deg, which is fine.

[badidas]

if you live in auckland i can have a look at it for ya

at a guess id say the mechanic has stopped the overheating by drilling holes in the thermostat which means the water flows more and less pressure on the cooling system it will help it run colder
but it also means that the cold start injector will be working overtime everytime the car goes cold and it can eventualy dammage the engine
my mate did this to a $500 fxgt he had and it lasted a year before the engine spat the dummy big time

pm me if keen

[matt dunn]

but it also means that the cold start injector will be working overtime everytime the car goes cold

The cold start injector only work when the car is starting.
It is powered by the cranking feed to the starter so it's impossible for it to operate unless you hold the key in the start position.

Matt

[badidas]

ok so it looks like ive got that one abit off bit it still means the car will run ritch use gass and mabey even bore wash

[MrBob]

it still means the car will run ritch use gass and mabey even bore wash

not likely. he said his temp only drops to about a about a 1/4 on the gauge. My cold start shuts off just over 50 deg, which is quite a bit below this.

If its really bugging you then just replace the thermostat again, its cheap and maybe it'll give you some piece of mind ?