D5 Thermostat / water temp

[outnumbered]

yes the one at the bottom is a pain to get to you can just get in with an angled torxe,no gasket comes with the new one . check and see the old one is okay if not use gasket seal. its the 2 torxe screws at the top and not the whole housing
mike

[Garett]

When you say angled torx do you mean something like one of these?

i.e. a allen key style torx

http://www.tooled-up.com/Product.asp?PID=13483

Its a right pain to get at and need to buy the correct tool for the job, my normal torx bits are too deep to fit in such a narrow gap!

[R-P]

Thanks for this thread guys.

Mine would pretty much heat up before I reached the edge of town (and it is a tiny town...) to slam in the middle. Now it is stuck one increment lower even when going for an hour long motorway drive.

I will assume it is the thermostat and try to find a replacement.

How bad is it exactly if it does get warm but just not compeletly?

Supposedly the Prius II (my other car) never gets up to normal car operating temperatures unless it is >30C outside (others checked with scangauge and other instruments, as Toyota omitted any visual check, probably BECAUSE it never reaches operating temp), hence people plugging up half the radiator for lower drag and it still not reaching operating temperature. So it doesn't seem to do much harm to an (Atkinson cycle) petrol engine...

[cheshired5]

Originally Posted by R-P

Thanks for this thread guys.

Mine would pretty much heat up before I reached the edge of town (and it is a tiny town...) to slam in the middle. Now it is stuck one increment lower even when going for an hour long motorway drive.

I will assume it is the thermostat and try to find a replacement.

How bad is it exactly if it does get warm but just not compeletly?

Short term, not that bad. Your in car heater may not be as warm and your fuel consumption will increase because the engine isn't running at optimal temperature but there's the very real possibility that the thermostat may unstick itself and close but then stay closed and that could be very serious indeed.
I'd take the friendly warning that all is not well and sort it out.
There is the extra possibility though that your thermostat is in fact ok and your engine coolant temperature sensor is going bad and reporting a false reading.
The ECT is very easy to access though and resistance test to confirm correct operation.

[big bad wolf]

Mine started to take 10+ miles to get to the right temp. and i noticed my fuel consumption gradually increasing - the avge dropped by nearly 10 mpg.
I was initially horrified at the cost of the thermostat and housing, but thanks to this forum i came upon the Gates item and managed to get one for £16.
I installed the thermostat on Saturday (what a mission - would take no more than 15 minutes on most previous cars) and now the car is to temperature in 4 miles even with outside temperatures of about 2 degrees celcius.
My avge fuel consumption has gradually started to creep up and i will check with a tankfull from tomorrow. Fuel tankfulls reduced from about 730 to latest tankfull of near 580. Hopefully should be back to normal.

[oragex]

This is a thermostat replacement on a 2.4 petrol, I guess pretty similar to the D5 one

https://www.youtube.com/watch?v=P4ct...9r708ezTOAKxLA

To check for a stuck open t-stat (the temp needle taking to long to rise) start the engine from cold, let it run 2 minutes, then check the upper radiator hose, it should still be very cold - if it's a bit warm, the t-stat is stuck open

[oragex]

Originally Posted by oragex

This is a thermostat replacement on a 2.4 petrol, I guess pretty similar to the D5 one

https://www.youtube.com/watch?v=P4ct...9r708ezTOAKxLA

To check for a stuck open t-stat (the temp needle taking to long to rise) start the engine from cold, let it run 2 minutes, then check the upper radiator hose, it should still be very cold - if it's a bit warm, the t-stat is stuck open

Just had a feedback from a D5 owner, on the diesel engine the lower torx bolt cannot be accessed like on petrol engines.

[Willow place]

After blanking off the EGR the temperature took longer to hit the middle on my car, will try the Oragex test just as a precaution !