Faulty Thermostat Sensor or just me???

[im2bad4ya]

Hey guys. I just wanna say two things.


First off I really do use the search functions before I post on a topic.

And secondly, sorry I'm hogging up the last few threads with my issues, but my car is really just stubborn I guess, I just want to make her 100%.............



With that out of the way, I replaced my thermostat sensor yesterday. The terminal on the old was hanging and spinning freely off the bolt. So I would get intermittent operation, for example when I hit a bump on the road, the needle would jump from off to on. Normal operating temp on the gauge with my broken sensor would be just a little bit below the center of C/H.

So I replaced the sensor to have a gauge that works full time. How hard can it be, screw in a bolt, connect a wire and done.


Well, this is what operating temperature looks like now:





My cluster is from a V6, but the fuel gauge/temp gauge should read the same anyway right? (it did with the old sensor) I don't know why it's reading like this. Of course there is always the possibility that my engine IS ACTUALLY running that hot! Of course I doubt that tho, I just want to get this gauge working. Should I try resetting the computer?

[Mi|<E]

Any coolant leaking? Ive had the needle up there but my water pump was
on the way out. Check for leaks and if there are none then go on to burp
the coolant to get any excess air pockets out of the system. Air can
cause the needle to flutter on bumps.

[wytbishop]

I'd say air too. The sensor for the gauge is at the highest point in the filler neck so if there's an air pocket there it's not sensing coolant temp it's sensing the temp of that air pocket which is going to be a bit higher.

[im2bad4ya]

I'll check for air. Brand new water pump and timing belt installed two weeks ago. No coolant leaks. The reason the needle "fluttered" as you say didn't have to do with anything mechanical, it was electrical, the terminal on the sensor was half broken, so when I hit bumps, it jiggled the wire to loose power for that second or two. Tho when I squeeze the upper radiator hose, it doesn't feel like it's filled up all the way, but I heard that's not a big deal. Maybe I have an issue with my thermostat not opening all the way?

[wytbishop]

Not having the cooling system completely full can but won't always affect a couple of things. It can cause what you're seeing with your temp and it can also affect the idle for the same reason. Throttle body senses the air temperature of the bubble not the coolant temperature.

[kudkudniyog]

Mine is doing the same thing. However, it is pegged over the max. I just replaced the gauges recently and I think it is from a GS. Mine is 4 cyl.

[im2bad4ya]

yeah, it really sucks, does anyone know how to 'properly' bleed air from this system? i've been squeezing the upper radiator hose with the cap off, ive gotten as much air as i can out doing it like that

[wytbishop]

-With the engine off and cold remove the rad cap.
-Now remove the engine side cap to allow gravity to fill the rad. Replace the rad cap before it overflows everywhere. If the rad is already full right to the top you can skip this step.
-Start the engine with the engine side cap off.
-Fill the engine side with the engine running. As air is circulated to the top the level will go down. Continue adding until it stops going down. This will usually only take a minute.
-Replace the engine fill cap.
-Ensure that the overflow tank is filled to the cold full line.

Now it's full and there should be no air in the system. Take it for a drive and get it right up to temp. Any air that might still be in the rad will be pushed out into the overflow tank as the coolant expands. Before you shut the engine down make sure the overflow is full to the full hot line.

When you turn the engine off and the coolant starts to cool it will suck the overflow back into the system. If you wait a couple of minutes you can actually see and hear this happening. If the overflow level is too low the engine will suck a bunch of air back in so make sure it's up to the full hot line before you shut the engine off.

[im2bad4ya]

what and where is the engine side cap? im only familiar with the radiator cap and resivoir tank cap

[wytbishop]

Oh wait...4 cyl...I forget sometimes that not everyone has a GS.

Let the engine cool all the way down then start the engine and add coolant to the rad until it stops going down. Then fill the overflow to the cold line. Take it for a drive to get it hot and fill it to the hot line and shut it off.

[im2bad4ya]

no, I've been driving like this for a long while now with the radiator fluid topped and the reservoir to the full line.......I have bigger fish to fry now, with my car not cranking at all and the diagnostics code coming up with code 02 - no ne-signal.............it's not fair!!!

[SuperK]

Bad distributor?

Also, if you noticed that your coolant was bubbling... bad head gasket.

[im2bad4ya]

Bad distributor?

Also, if you noticed that your coolant was bubbling... bad head gasket.

Highly doubtful. This happened after I got a new thermostat sensor. First time turning on the car after installing it. I think I have a loose wire or lifted ground somewhere. Car doesn't overheat, head gasket is good. Somewhere in the path, the signal is reading incorrectly.......

[SuperK]

maybe I read that wrong... will it turn over, but not start, or not turning over at all?
If it doesn't turn over... I would agree with the grounding.

[im2bad4ya]

My car runs, no problems at all. The issue is that the thermostat on my gauge cluster isn't reading engine temp properly, if you see the pic on the first post, the needle is on the H line. That's been normal operating temperature since I put the new sensor on. The needle will only occasionally bump down towards the center, but very rarely, only for it to go back up to that H line.