I have a 1988 pickup, 22R with carb, 150K miles, no a/c, 5 speed manual. I have owned it 17 years and it just keeps on running.

It has the base instrument cluster. For some goofy reason after all these years I bought an SR5 cluster from ebay a few days ago. The seller said it was from a 1988 4cylinder 4Runner. I think that year 4Runner 4 cylinder was only available in fuel injection. Don't have the cluster yet.

While driving back from the parts places looking for an oil pressure sender for the SR5 cluster, I took what may be my last look at my base cluster.

The water temp gauge on my truck has never gone to the middle. All these years I though Toyotas were just cold blooded. The water temp sender and gauge must work because the indicator does move. It just moves very little. If it is very hot outside and I am stuck in traffic it moves up just a little more, almost to the middle.

Will be interesting to see if I get the same reading with the SR5 cluster.

Anyway, do I have some strange cold blooded Toyota? This is a picture from today after driving for an hour in 55 degree temp.

The truck has never overheated. I replaced the radiator years ago but my gauge was like this from day one. My heater works fine.

 

yea, mine does something similar. i wouldn't worry about it. Could be that the engine really is a little colder than you think, perhaps just below its suggested op range. Once you get the new one in, if it does the same thing, i wouldn't worry.

 

Do this:
Check the resistance in on the sensor with the truck cold for 24 hours. Note the air temp.
Check the resistance on the sensor with the truck at operating temperature. You should be at 190-200 degrees (approx) with a stock thermostat.

It should follow a scale LIKE the one below - don't expect the same values, as this one is for a different sensor:
http://lakebox.dnsalias.com/photos/1...r-nongauge.gif


If you really want to get medieval on it, pull it out:
1) Test resistance in a cup of ice water.
2) Test resistance in at room temperature.
3) Test resistance in a cup of boling water.

You know that boiling water is just a bit above standard operating temperature, using a resistor - plug the appropriate resistor into the sender wire and ground it. Your temp gauge should read about "normal" - maybe a little above with the key in the ON position.

I believe the 1988 gauges are electrically dampened - that is, my gauge stays dead cold, immediately jumps to "normal" after about 2 minutes, despite the motor not being up to temp.

 

Many car companies have "idiot gauges" that jump to the normal range no matter what the engine is doing. The oil pressure and water temp gauges always seem to be in the middle with idiot gauges.

In 17 years my water temp gauge has never jumped to the middle. In 17 years it has been up to operating temp a few times. So I think I have had an abnormal gauge or sender after all these years.

If I get the same results with the SR5 cluster I will get out my ohm meter to check the sender or simply replace it.

This is a picture of when the truck is cold with the ignition on. As you can see from the first picture, the gauge moves, it just moves very little.

 

Do you have stock (190*) thermostat?

 

I assume so. I bought the truck when it was 1 year old. The guy before me just messed around with the stereo.

I can't see how it would matter even if it had no thermostat. I live in sunny California. The engine gets hot. Even when it is cold outside my heater works after a few minutes.

Now that I have searched on the board for other messages there is something going on with the gauge or sender, for 17 years. I am only thinking about it now because I am waiting for the SR5 cluster.

 

SR5 cluster came today. I did a test fit. Engine was not cold, not hot, I would call it warm.

Gauge is where I would expect it to be on my little test drive.

So the water temp gauge on my original cluster has been reading low after all these years.

 

That's cool that all the gauges on yours are working. When I bought my truck it already had an SR5 cluster installed but hardly any of the guages were working. So I went to a basic cluster and installed aftermarket gauges.

Rob

 

On my SR5 setup for my non-SR5 truck, a temp gauge reading like that would be 1-2 minutes just past start up.. Basically it sits, jumps to a normal range and tends to stay there until the temp gets above 212 or so... Might check your thermostat one of these days.. Does the heater blow pretty hot or not?

 

Now that you mention it, the heater has never been hot, hot. But there is little need for a real heater in Silicon Valley. I do use the defroster and it blows what I would say is warm. It has been this way since I bought the truck in 1989. One of these decades I will check the thermostat.

I have driven for 2 days with the SR5 cluster. The needle starts to move then it jumps. It is in the 50s outside so I will see if it goes to the middle in the summer.

All I can say is the SR5 gauge moves a lot more than the original cluster ever did. So my original water temp gauge is a bit slow....

 

so i think i am understanding that what you guys are saying is that the sr5 water temp is goofy like mine, but normal. as soon as i crank my truck the guage jumps right to the normal position. it seemed like the original cluster would move in conjunction with the temp, just like all vehicles i have owned, slowly to the normal temp as the engine warmed, but this sr5 cluster jumps right up to normal. every once in a while it will stay down and then pop up to the normal spot. the normal spot i speak of is just below halfway like in the pictures above.

 

If it blows warm, check the thermostat.

toyotaholic, mine is like that too.. I crank and within 1-2 minutes it jumps to the "normal" range.