Dash Temperature gauge low and loose

[silverscoot]

Hi!

Just back from a lovely ToyoVamping 1000 km trip and noticed when I drive the temperature gauge on the dash goes from cold to mid warm normally but then starts falling towards cold and the needle starts loosely bouncing as I drive.

Could the problem be just in the dash read out mecanism or do I more likely need to replace the T-stat in the engine?

Does the T-stat just give a temperature reading on the dash or does it tell the fan when to go on to cool the engine? I have dreamed of having a digital read out on the dash so as to never overheat the van.

Seems on my van, the fan is always on...

Is it safe to keep driving around short trips round town till i get this fixed?

cheers

:?:

[Flecker]

Hi!

Just back from a lovely ToyoVamping 1000 km trip and noticed when I drive the temperature gauge on the dash goes from cold to mid warm normally but then starts falling towards cold and the needle starts loosely bouncing as I drive.

Could the problem be just in the dash read out mecanism or do I more likely need to replace the T-stat in the engine?

Does the T-stat just give a temperature reading on the dash or does it tell the fan when to go on to cool the engine? I have dreamed of having a digital read out on the dash so as to never overheat the van.

Is it safe to keep driving around short trips round town till i get this fixed?

cheers

:?:


Short trips would be fine... more than likely the t-stat failed open causing constant recirculation of the coolant, which will make it run cooler obviously. Replace with the oem TOYOTA t-stat. Can be found here:
https://www.amazon.com/TOYOTA-90916-03046-Genuine-Toyota-Thermostat/dp/B00KTKWC9S/ref=sr_1_4?keywords=thermostat&qid=1567533294&s=automotive&sr=1-4&vehicle=1987-76-942-995--49-8-8-4776-1893-9-1-1996-191-4&vehicleName=1987+Toyota+Van
& here:
https://www.rockauto.com/en/catalog/toyota,1987,van,2.2l+l4,1279784,cooling+system,the rmostat,2200

The Rockauto one is the Aisin t-stat... and just as reliable as the Toyota.

Hope that helpeth thee my good sir.

[silverscoot]

Thanx. Glad to have those part numbers handy. But before I go replacing the T stat, I wanna be sure...
When my van is on, the fan is always spinning, even when I start the van and it is cold. Is that normal?
If it is the t stat, I'm glad to have it open and running cold rather than hot.

[trestlehed]

You should only use the OEM Toyota thermostat.
Here is an article on how to replace your thermostat. In addition to the library article
you should read all 4 pages of the thread in order to educate yourself on the importance of using only an OEM thermostat:
https://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat
(https://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat)

If your fan is continously engaged you most likely have a bad fan clutch.
If so, either rebuild it or replace. Use the TVT search function. Timsrv has a write-up on how to determine
if your fan clutch has gone bad.

I'm not sure why your temp gauge needle is bouncing.
That's a new defect that I haven't heard/read about yet.

Good luck!

[silverscoot]

yes, thanx for the help. I replaced the t stat and the temp gague is regular again. The needle still bounces when i go over a bump...
So next, seems i will replace the fan clutch. Anyone have that part # handy? I reckon its probably at rockauto...

Once the mechanic is in there changing the fan clutch, should I just change the water pump? its been 2 or 3 decades working reliably so far...
:silvervan:

[JPERL]

yes, thanx for the help. I replaced the t stat and the temp gague is regular again. The needle still bounces when i go over a bump...
So next, seems i will replace the fan clutch. Anyone have that part # handy? I reckon its probably at rockauto...

Once the mechanic is in there changing the fan clutch, should I just change the water pump? its been 2 or 3 decades working reliably so far...
:silvervan:

Those needles are sensitive to road shock and bounce nothing really unusual.

[Flecker]

You should only use the OEM Toyota thermostat.
Here is an article on how to replace your thermostat. In addition to the library article
you should read all 4 pages of the thread in order to educate yourself on the importance of using only an OEM thermostat:
https://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat
(https://www.toyotavantech.com/forum/showthread.php?21-Replacing-your-van-s-thermostat)

If your fan is continously engaged you most likely have a bad fan clutch.
If so, either rebuild it or replace. Use the TVT search function. Timsrv has a write-up on how to determine
if your fan clutch has gone bad.

I'm not sure why your temp gauge needle is bouncing.
That's a new defect that I haven't heard/read about yet.

Good luck!

I'm running the Aisin t-stat with the same results the Toyota one had... Aisin is fine.