Stuck open thermostat.

[BigRAWesty]

Ok so today while driving around I've noticed the normal driving temp ranges from 83 threw to mid 90's.
But when pulled up and at idle for 5-10 mins coolent temp drops right off to like 60 ish..

Now my understanding is the thermostat should close keeping engine temps up around 80 odd and then open when around 88??

So with my temps dropping so low is it unreasonable to suspect a stuck open thermostat?

[trekster]

How are you measuring the temperature? Aftermarket gauge?

[MB]

Sounds absolutely plausible to me mate!

What ambient temperature was today in your neck of the woods firstly?


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[MB]

Pull the stat out, chuck it in a pot on the stove with a thermometer and watch what she does:-) ! Battery 1% over&out mate!


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[the evil twin]

Those symptoms are either a failed thermo or no thermo at all

[Clunk]

Or feel the hose that feeds the thermostat..... it'll be firm when the thermostat is closed and fairly soft when open.......... or you can keep the radiator cap off and watch the flow of coolant back into the radiator. ...... well that's what I used to do with my old TB42

[jay see]

Pull the stat out, chuck it in a pot on the stove with a thermometer and watch what she does:-) ! Battery 1% over&out mate!


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This is what I done. My stat was stuck open my about 2-3mm.

[BigRAWesty]

Sorry. Should have written..
Temps taken off the scan gauge..
And we've had quite mild temperature here, around the mid teens to low 20's.. I'll get wife to observe more as she's in it more than me..

[threedogs]

This is what I done. My stat was stuck open my about 2-3mm.

So your an old hand at this, good to hear

[Sir Roofy]

So your an old hand at this, good to hear

4.5 is different to a 3L

[mudski]

4.5 is different to a 3L

Just a tad. jaysee might be in for a surprise when he gets to Johns. Lol.

[Sir Roofy]

Just a tad. jaysee might be in for a surprise when he gets to Johns. Lol.

yep but he can get in tight spots better than me

[threedogs]

Im not too bad in small spots, you may be surprised what John and I can acheive
Plenty of bandaids he he he

[BigRAWesty]

Ow yea.. I just remebered all this chat of a shoit location on the 3ltr

[jay see]

So your an old hand at this, good to hear

Yep, on my own cars.


4.5 is different to a 3L

No not really, sames things just in a different place. Will work our way through it. I've had a heap of different of cars over the years.


Just a tad. jaysee might be in for a surprise when he gets to Johns. Lol.

Always up for a challenge....


yep but he can get in tight spots better than me

Well well see about that.


Im not too bad in small spots, you may be surprised what John and I can acheive
Plenty of bandaids he he he

Hopefully not.

[garett]

66172
this is a thermostat from a td42. seized open.
couldn't get it warm normal driving had to thrash it up a steep hill to warm it a bit.
then it would cool off pretty quickly.

[BigRAWesty]

66172
this is a thermostat from a td42. seized open.
couldn't get it warm normal driving had to thrash it up a steep hill to warm it a bit.
then it would cool off pretty quickly.
My td42 thermostat was also frozen open..
Had no idea untill I removed it at 500,000k overhaul lol..
No wonder the heaters took forever to work lol..

[Wizard52]

Ok so today while driving around I've noticed the normal driving temp ranges from 83 threw to mid 90's.
But when pulled up and at idle for 5-10 mins coolent temp drops right off to like 60 ish..

Now my understanding is the thermostat should close keeping engine temps up around 80 odd and then open when around 88??

So with my temps dropping so low is it unreasonable to suspect a stuck open thermostat?

Just installed VDO temp gauge in ute and noticed same issue. Temps vary from about 75 to 85 degrees depending on load when on the move but yesterday in Brisvagas traffic noticed temp just once drop to about 50 when stopped at lights. New thermostat installed at same time as new Dessert Cooler radiator and gauge.

[BigRAWesty]

Hmm interesting.. did you test thermostat before installing?

[Sir Roofy]

But if your working your engines hard and temps rise a bit while at it, when you back of go slow stop and idle
then the temps are going to drop any way ?

[4bye4]

A thermostat is a fairly lazy device. I am not sure how long it would take from fully open when you are driving hard to fully closed when stopped at the lights. Its possible I would think that the temp is falling off until the thermostat catches up and regulates the temp of the water as it is supposed to do.

[Wizard52]

Hmm interesting.. did you test thermostat before installing?

Brand new one

[mudnut]

Yep I have been stuck on the side of a busy highway because the brand new thermostat I had put in failed to open, I test any thermostat I am going to install and I advise anyone to check them by putting them in a pot of boiling water and seeing they work.

[MB]

Those symptoms are either a failed thermo or no thermo at all ..........:-)

[MB]

Apologies ET for ...... Forum Runner makes us add at least 10 characters :-(

[MB]

<img src="http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=66172"/> this is a thermostat from a td42. seized open. couldn't get it warm normal driving had to thrash it up a steep hill to warm it a bit. then it would cool off pretty quickly.

Nihao Garett,

Cooling systems on any car are strange and confusing at best, well stock designed by Nissan we have :-) !

My own personal experience is that in an emergency we can pull out any cars jammed TS and thereafter experience exactly what you're describing.


Cheers MB

[BigRAWesty]

So I'm really unsure now..
Had car up to 87oC tonight and now had it idling for about 10 mins and it's only dropped to 84oC...
It's currently 11.5oC outside..
Maybe it's in its way out..

[MB]

G'day Westy,
Such a cheap and easy part to changeover/test, honestly worth a try first old mate!
Yanks I've worked with change em seasonally to suit their radical climate +/- 110/40 :-)


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[BigRAWesty]

G'day Westy,
Such a cheap and easy part to changeover/test, honestly worth a try first old mate!
Yanks I've worked with change em seasonally to suit their radical climate +/- 110/40 :-)


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Yea I've had a look at the zd30 thermostat location. ...
It's not pretty lol

[Hodge]

Just ask threedogs he just went through that drama lol.

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[threedogs]

So I'm really unsure now..
Had car up to 87oC tonight and now had it idling for about 10 mins and it's only dropped to 84oC...
It's currently 11.5oC outside..
Maybe it's in its way out..

Nothing wrong with those numbers at all.
Any cooling system will recover when left to idle uness you have a fan issue
Wheres the Patrol from again as in History

[BigRAWesty]

Nothing wrong with those numbers at all.
Any cooling system will recover when left to idle uness you have a fan issue
Wheres the Patrol from again as in History
Ex cfs from baccasmarsh..
Yea I realize it'll come down. The other day it dropped from mid 80's to low 70's

[threedogs]

So it should have an 83 degree fitted, goodluck pulling it out.
Remove the shroud, plastic fan and alternator.
Thats if its similar to mine

[BigRAWesty]

So it should have an 83 degree fitted, goodluck pulling it out.
Remove the shroud, plastic fan and alternator.
Thats if its similar to mine
Yep I'd say it is....

[the evil twin]

Yep I'd say it is....

Thats the standard thermo for Aus.. the 78 is Gulf spec and the 88 is for the cold bits of the planet

[jay see]

Yea I've had a look at the zd30 thermostat location. ...
It's not pretty lol

It's not that bad, but small hand help.

[threedogs]

Bacchus Marsh is only up the road from me
so a 83 thermostat would be Ok, just a word of
warning ,,,,be very carefull with the shroud its
very brittle, you only need to remove the bottom
bit and the top half. That will give you plenty of
room to access the thermostat. Just lay a few blankets
over the bull bar and the top of the radiator,
beware that overflow spout on top of the radiator to

[Clunk]

So did you try what I said?

[BigRAWesty]

So did you try what I said?
I did.. and it feels soft but I'm not sure what the zd feels like as it has 2 feeds to the top tank.. one from the engine and one from the radiator..

[Clunk]

I dont know how different they are to TB42 or TD42, but Im talking about the large pipe that goes from the radiator to the thermostat housing.

[threedogs]

Cant reach that on my Di too much covering it.

[threedogs]

If it was stuck open hyperthetically, would the temps just get warmer and warmer .
Not talking open road, as that should keep its self cool. Im talking around the burbs
Just saying

[the evil twin]

If it was stuck open hyperthetically, would the temps just get warmer and warmer .
Not talking open road, as that should keep its self cool. Im talking around the burbs
Just saying

Not necessarily

[garett]

nah mine didn't even warm up, and other cars got to operating at lights but as soon as you move off it cools and the fan works too.