Normal Temperature Gauge Read-out?

jjklongisland

Registered User
I feel that my car 89 is running hot. Since this is my first superchicken and I do not have an infrared thermometer is the photo of the attached gauge the normal position for a warmed up SC.



I recently did a full tune up, changed the thermostat (stock replacement), changed the temperature sending unit since my gauge did not move when I first got my sc a few months back, changed all the coolant hoses and belts, and changed the coolant. Any thoughts or is this normal?
 
I bet your high speed fan isn't coming on. That gauge isn't really accurate, but mine sits by the NO.

I put a relay and a switch on my car and when I'm in town I run the low speed fan constantly. On the highway I flip it off since there's plenty of airflow to the radiator.
 
I would suspect that the gauge should be more toward the middle, but you really can't tell from the stock gauge. For all you know it's the calibration of the gauge. When you first start the car does the needle flat line to the left?

Is that the position the needle always ends up at, regardless of how you drive the car and when you check? It's been cool the last several days, has that affected where it sits?

If you are concerned than the only real way to know is to hook up a real gauge, but you already know that. Sorry I don't have anything sitting around that we could hook up quickly and check it out.

btw - sorry for not getting back to you. I'll give you a call this weekend, probably Sunday morning.

Ira
 
I would suspect that the gauge should be more toward the middle, but you really can't tell from the stock gauge. For all you know it's the calibration of the gauge. When you first start the car does the needle flat line to the left?

Is that the position the needle always ends up at, regardless of how you drive the car and when you check? It's been cool the last several days, has that affected where it sits?

If you are concerned than the only real way to know is to hook up a real gauge, but you already know that. Sorry I don't have anything sitting around that we could hook up quickly and check it out.

btw - sorry for not getting back to you. I'll give you a call this weekend, probably Sunday morning.

Ira


No problem about getting back to me. We are all busy these days.

As far as the gauge, it always starts off pegged to the left and takes a decent amount of driving to get up to temp. When its warmed up, regardless if I am on the highway or in Town it seams to stay consistent at the position of the photo. The fan seams to be operating normal but havent looked at it when it goes to high speed.
 
I recall a service bulletin (902310 NOV 90 Temp. Gauge Not Functioning Correctly, Supercharged Engines) for the temp gauge, where some owners thought their car was running too hot (when it wasn't) - with the fix being a new _matched_ pair of gauge and sender.

Is there a colored ring on your sender? Does it move at all when the fan cycles?

Try removing the press-on connector at the sender, then cleaning it and the sender terminal - squeeze the connector just a tiny bit so it is snug when pushed back on. Mine used to barely move until I did that. Now it raises correctly and won't go past M.

You can also try replacing the sender.

It doesn't sound like you have reason to suspect the engine is overheating, and as others note the gauge is just a reference, so we won't go there for now :)

Also….I agree on adding Water Wetter, in any case.
 
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I changed the sending unit when I did the tune up. I am going to borrow my buddies laser thermometer. I am guessing the exterior of the block should be pretty close to the 190 degree mark, correct?:confused:
 
If you mean the t-stat opening temp (192º), I don't think so. Block temps vary depending on where you test, of course.

See what you get on the thermostat housing before it mates to the top hose & at the t-stat bulge, then at the end of the hose where it mates to the top of the radiator.

Do you have another temp gauge you can swap into the cluster?

Where did it ride with the old sender?

But again, I don't think you're chasing an overheating issue…right?
 
If you mean the t-stat opening temp (192º), I don't think so. Block temps vary depending on where you test, of course.

See what you get on the thermostat housing before it mates to the top hose & at the t-stat bulge, then at the end of the hose where it mates to the top of the radiator.

Do you have another temp gauge you can swap into the cluster?

Where did it ride with the old sender?

But again, I don't think you're chasing an overheating issue…right?

The old sending unit was bad. It never moved off cold since I got her. I guess I can chance the sending unit again and see if it changes.
 
If you try it again, be sure to brighten up the terminal and apply a bit of dielectric. If tempted to use teflon tape as a sealant, go easy cover just the last few threads that are captured, so as to not inhibit current flow/resistance.
 
My 95 auto will climb that high in stop and go traffic, almost forced to turn the AC on to cool it down :mad:

On the other hand my 90 auto can sit there and idle in 100 degree temps and not climb 1/4 of the way up the gauge ????

The fans work perfect in both cars ??? The factory gauges leave a lot to be desired !!
 
How do I hook up an aftermarket temperature gauge? I have never done any aftermarket gauges. Last night I drove the car and it was nice and cool out. For the first 10 minutes she was very responsive and fast. When the needle was between the N and the O it still was quick. As soon as she got to the same spot as attached she was very sluggish, not responsive etc. I would like to trouble shoot the problem but I think I need to know what temp see is actually running at.
 
Heat reduces air % (it expands) in the boost stream. Less air %/density, less power. Basically what you describe is typical.

If you have an idea of the boost level change drop, maybe someone can speculate if there is something abnormal in your case. What was the boost when it was 'sluggish'?

You can buy a mechanical or electric water temp sender. Sweep or digital. Instructions come with a gauge when you buy it. Cut it into the dash or mount a pod on the driver side window pillar.

Did you laser gun the temps yet?
 
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Heat reduces air % (it expands) in the boost stream. Less air %/density, less power. Basically what you describe is typical.

If you have an idea of the boost level change drop, maybe someone can speculate if there is something abnormal in your case. What was the boost when it was 'sluggish'?

You can buy a mechanical or electric water temp sender. Sweep or digital. Instructions come with a gauge when you buy it. Cut it into the dash or mount a pod on the driver side window pillar.

Did you laser gun the temps yet?

I am definately familiar with the cooler the outside temp the quicker she runs but I was trying to correlate the fact that she ran good even between the N and the O but noticeably sluggish at the higher factory gauge readout. So basically what I am saying, not that I hope there is a problem but I would love her to be as responsive as she was between the N and the O. As far as the temp gun, my neighbor is away. He comes back this evening so hopefully sometime after work.

As far as the water temp gauge, I didnt know if it has a separate lead that goes all they way up to the sending unit or if I just tie it into the wire behind the dash.

Whats your first recommendation, find out the temp using a gauge or start swapping out thermostats and/or sending units which are both brand new.
 
Aftermarket temp gauges usually need to be matched with their own sender. Then you need to tap it in somewhere or try to adapt/add it to where the stock sender is in the t-stat housing. I would expect to have to add new wiring for it, including 12v for the lighting.

See these threads:
- http://www.sccoa.com/forums/showthread.php?t=76343&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=82597&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=54536&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=94060&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=112030&highlight=aftermarket+water+temp+gauge

I'd like to see you hook up with a local SC owner (Ira?) and get their opinion on what your car is actually doing :)
 
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Aftermarket temp gauges usually need to be matched with their own sender. Then you need to tap it in somewhere or try to adapt/add it to where the stock sender is in the t-stat housing. I would expect to have to add new wiring for it, including 12v for the lighting.

See these threads:
- http://www.sccoa.com/forums/showthread.php?t=76343&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=82597&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=54536&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=94060&highlight=aftermarket+water+temp+gauge
- http://www.sccoa.com/forums/showthread.php?t=112030&highlight=aftermarket+water+temp+gauge

I'd like to see you hook up with a local SC owner (Ira?) and get their opinion on what your car is actually doing :)

Ira and I have been meaning to meet up. Out schedules have been a little nuts. I am sure we will get together soon. I unfortunately am going to bombard him with questions. I hope he is ready to spread some of that knowledge.

Thanks for the threads.
 
Ira and I have been meaning to meet up. Out schedules have been a little nuts. I am sure we will get together soon. I unfortunately am going to bombard him with questions. I hope he is ready to spread some of that knowledge.

Thanks for the threads.

Ira is back from the Shoot Out and over the bug that kept him in bed all weekend and should be very available this weekend unless The Boss changes her mind for some reason. If the weather stays cool I am sure we will take the car out for a spin one afternoon ;) so meeting up shouldn't be an issue.

I will call you later this week if that's okay. I don't have an extra temp gauge laying around though. If you use the temp gun don't shoot the block. Shoot the heater hoses in the rear of the engine. But getting a real gauge is the best way to know for sure. Their very easy to hook up and usually not very expensive if you are willing to go that route. Even a cheap one is better than what you have now.

Ira
 
If you are thinking about using a IR gun to get accurate temperatures you just wont. And again..Try some water wetter from redline
 
If you are thinking about using a IR gun to get accurate temperatures you just wont.

Those guns are extremely accurate when used properly, which isn't difficult. They make a great diagnostic tool, especially for the low cost compared to other means. In this case, the idea is to have a reference for troubleshooting, etc.. I'd certainly trust one any day over the stock gauge :)
 
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