Temp gauge

BarryK · 08-16-04, 10:16 AM

well, BABY is now showing another problem again.

About a week ago the temp gauge starting to not register above approx 110 degrees. Even on a very hot day and after driving for a good amount of time the temp gauge won't go above approx 110.
What are the chances this is only the sender unit going bad?

If I had an actually cooling system problem the car would be running HOT instead of cold right??!!

Is it possible to check the sender unit and is it relatively easy?. how hard is it to replace if I need to and can I get one locally like at Autozone or Pepboys or do I need to order a specific one from LICS.

Barry

PS: I knew 2 or 3 weeks without any problems was pushing my luck and something was due to crop up soon!

vetzs · 08-16-04, 10:36 AM

Turn Ignition on, remove wire from sender, the gauge should now show full cold. Ground the wire for an instant, the guage should show full hot. If this is the case the gauge is good and you should replace the sender. Get a TU-5 from Auto Zone.

BarryK · 08-16-04, 10:38 AM

thanks for the quick answer!
now for the really dumb question.......just where is the sender located on the motor so I can do the test you explained?

Barry

vetzs · 08-16-04, 10:40 AM

Directly under the Thermstat housing

vetzs · 08-16-04, 10:44 AM

One other thing, don't be tempted to use thread sealing tape when installing the sender.

BarryK · 08-16-04, 10:47 AM

Quote:

Originally Posted by vetzs

Directly under the Thermstat housing

ok, I admit it, I'm an idiot and i've never really done any motor work on this car at all so you can guess what my next question is........
just where is the themostat housing?

I just went to look at the motor. Is the themostat the thing in the intake manifold just behind the oil filler tube and to the side of the gas filter housing?. It has a single green wire going into it.

BarryK · 08-16-04, 11:48 AM

well, the problem is the sender unit went bad on me.
I pulled the wire and touched it to ground and it pegged the gauge so i'm off to get a replacement sender unit this afternoon. Pepboys is close so hopefully they will have one.

Thanks for all your help! looks like this will be the first "repair" that i'm doing myself without have to shell out big bucks to a mechanic for. They would probably charge me $60-$75 for what took me only 2 minutes to do!

tlong · 08-16-04, 12:38 PM

Now there ya go Barry! You are owning that vette, not just driving it.

I have followed your travails, and hope this gives you confidence to get involved in maintaining your baby first hand. It's fun, and if you screw it up then hire someone to fix it for you. Good luck.
tlong

BarryK · 08-16-04, 01:04 PM

Hi tlong

I'm sure everyone on here has become pretty familiar with my trials with BABY!

thanks for the kind words though and it WILL feel good to actually be able to do some of the work on her for repairs and maintaince even if it's just simple jobs.

BarryK · 08-17-04, 10:04 AM

first thing this morning I went out to the garage and with the motor all nice and cold I unscrewed the sender unit from the intake manifold. I didn't bother to drain any coolant from the system first so I just packed a few rags around the unit beforehand and was just very slow and careful. The unit came out fine and not one drop of coolant came out of the system or was lost.
I installed the new sender unit. Gee, all of this took about 2 minutes total from start to finish including getting the rags and the socket wrench ready! for my very first "repair" job it was actually kind of anticlimatic but in a way I guess that good.
Started up the motor and made sure nothing was leaking or oozing out from the threads of the new sender unit and let the car warm up by just letting it sit and idle for 15-20 minutes.
Previously, the temp on the car never registered above 160 degrees according to the gauge in the dash, than recently it would barely register above 110 or so. After the car warmed up by idleing for 20 minutes the dash gauge was reading right on the mark between 180 and 240 (is that the mark for 200 or 225 degrees?). I than got in the car and took her for a short drive and while driving just around my neighborhood and therefore at slow speeds - nothing above 30mph - the temp gauge dropped to register just a little higher than 180.

So far it looks like the new sender unit is working pretty good. The next step will be for me to find someone with an IR gun to shoot the engine to compare the actual temp against what my in-dash gauge is reading to see how calibrated I am or how far off my readings are. In either case, it looks like i'm a lot closer to a true reading with the new sender unit than I was in the past.

WOW, doing my own work on the car is pretty satisfying. Ok, i'm ready for the next job now. give me a block, some pistons, rods, etc and i'm ready to build a motor from scratch!

Rowdy1 · 08-17-04, 10:19 AM

Good show man, kinda makes you at one with the machine no?

BarryK · 08-17-04, 10:42 AM

hi Rowdy

yep, does make me feel a bit more connected with her.

I know it was about the simplest job to do on the car short of replacing the air filter, LOL, but it still felt good being able to do it myself for a change instead of having to waste the money paying someone to do it for me.

c5vetter · 08-17-04, 12:26 PM

now rotate those tires

BarryK · 08-17-04, 01:16 PM

LOL Rick

actually, I guess it probably is about time for that.
I need to pick up a floor jack and stands but I guess I'll make that the first job I do once I get those items.

Barry

08-17-04, 11:14 PM

Congratulations, you've completed Corvette 101.
Next, in Corvette 102, you'll learn how to change the oil and discover how damn tricky those oil filters can be.
Congrats, Barry.