problem NOT solved! HELP

[magicv8]

I drove it a short ways to see if the air flow from driving would help cool it down but it didn't. Still staying at 215* - 220*.
QUOTE]

Barry - take the car down the highway at 55-65mph. If the temp gauge indicates overheating, the fan isn't the main problem. If the coolant isn't being puked, the gauge may be wrong - notice the green wire running above the LH valve cover - and make sure it is not laying on the center of the intake where the exhaust crossover heats the intake.

Also: Check the lower rad hose to see if there is a spring inside when you squeeze it. If not, look to see if it is collapsing when the tstat opens at 180-195F. It is also possible that the lower hose is self destructing internally and is plugged enough to prevent the rad water from reaching the engine.

PS When you installed the temp sender, you put it in with clean threads (like the factory did) - right? Pipe dope or teflon tape on the threads can screw up the readings.

 

[ctjackster]

Mike
i replaced the temp sender myself last summer and i don't remember it giving me readings this high after i put it in. i know the replacements are notorious for not being accurate but sheesh, this is a lot

ok, that's an interesting fact.

borrow an IR gun forthwith and shoot the upper rad hose near the t-stat. No more posting until you have done so. Now scat!

 

[JohnZ]

ok, that's an interesting fact.

borrow an IR gun forthwith and shoot the upper rad hose near the t-stat. No more posting until you have done so. Now scat!

I agree - the first thing to do when you have temp gauge symptoms of a cooling problem is to make sure you have a problem at all (before you start throwing money and parts at it). Corvette temp senders are notoriously inaccurate, and the replacements are usually worse. Before you do anything else, find someone with an I.R. gun and shoot the upper radiator hose just above the thermostat housing with the engine warmed up and check the gauge at the same time so you know what the gauge is really telling you; there's a good possibility you don't have a cooling problem at all.

Thread sealer on the temp sender can make the gauge read lower (higher resistance to ground), not higher; this is seldom an issue, as the pipe threads are sharp and seal by interference.

 

[magicv8]

IR gun here

http://www.jcwhitney.com/autoparts/Search?catalogId=10101&storeId=10101&sku=infrared

 

[Subfixer]

Look at how quickly we are filling Barry's toolbox. :L

 

[ctjackster]

the IR temp sensor was quite possibly the most fun I have had with a new tool in quite some time - I needed an hour to get all of the "juvenile" and "just curious" temp checks out of my system . . . .

 

[BarryK]

ok guys, I'll see where i can find an IR gun somewhere tomorrow one way or another.

BTW, just took a test drive in both traffic conditions and open highway.
220* steady on open highway, 225*-230* in traffic (according to gauge)

sorry Jack, I won't post again about this until after tomorrow when I find an IR gun somewhere

 

[ctjackster]

sorry Jack, I won't post again about this until after tomorrow when I find an IR gun somewhere

post all you want Barry (this place would see traffic drop by 50% if you were to let your keyboard go quiet :L ), but as for your run hot issue you might just have a very typical problem that is really not a problem at all - and before throwing money and time at it, you should rule out the "gauge is telling me my car is hot, but it's really not" scenario you have read about and might just be experiencing. PErhaps we can save your Al Knoch budget yet.

quick question - when did you put the new temp sensor in (YOU did it?) and when did you put the car into the paint shop? Yo got my attention with you mention of that task because you had said the car was running a steady 180 beforehand, from your memory, and now it wasn't - so something that CHANGED in between the days of 180 on the gauge and now is of interest.

 

[BarryK]

Jack

traffic wouldn't drop 50%, maybe 35%, but not 50% !

I put the temp sender unit in last summer before it went into the paint shop but don't remember exactly when. I do remember the readings were SLIGHTLY higher - maybe 10* or so but nothing like it is now at 40*-50* higher or you know I would have posted about this issue back than after I did it. And yes, I put it in - it was actually my first and only repair i did myself previous to the timing yesterday (not including R & R the PVC valve to clean it last year also).
If my car was reading 190* or so I wouldn't be concerned and would figure it was gefinately the sender unit.

Oh well, like everyone is now saying, no point in guessing anymore until I get hold of an IR gun and we know definately one way or another - maybe i'll get lucky and I really am chasing nothing at all. If the the sender unit is off that's fine, as long as I know it and know by how much so I can still evaluate the car and know it's ok.

 

[BarryK]

cool, just called the nearest NAPA store and they have an IR temp gun in stock AND on sale for $80.
I told them to put it aside and I'll get it in the morning


They don't have a fan clutch in stock but can get one for me within the same day or the next day if i need it for $46.00.
i'll hold off on that until we see what the IR gun says although the freespining on the fan is a concern according to what you all are saying but one thing at a time.

 

[Subfixer]

between working on the car and running back here to check and answer replies, and back to the car again, I'm exhausted and dripping wet (real humid here today).
i'm taking a break for an hour or so to clear my head before working on it again. already have a headache from this crap!

Time to move the computer into the garage......

 

[ctjackster]

cool, just called the nearest NAPA store and they have an IR temp gun in stock AND on sale for $80.
I told them to put it aside and I'll get it in the morning


They don't have a fan clutch in stock but can get one for me within the same day or the next day if i need it for $46.00.
i'll hold off on that until we see what the IR gun says although the freespining on the fan is a concern according to what you all are saying but one thing at a time.

Perhaps it will end up being a combination of these two (maybe your fan clutch is giving rise to 20 degrees of this problem, and your temp sending unit the other, false, 15 degrees), but learn from the mistakes of others (including myself) who have tried to address a problem on these cars by being less than methodical and end up fixing things that don't need fixing.

 

[BarryK]

Time to move the computer into the garage......

god NO!!! there is no A/C in there.
if i had A/C in there........... my wife would never see me

 

[BarryK]

Jack
either one is a relatively easy fix so i'll be happy if either or both is the problem and it fixes this issue once and for all.
thank god I can't get to the store until tomorrow because I'm fed up and and sick of this whole issue now today and my head is killing me.

Man, no matter how this turns out, I owe all you guys a cold brew at Carlisle. I may not be able to get my seats done now anyway because i'll have to use all that money for beers for you guys. The ironic part of that is i'll spend a fortune on beer (will be worth it though) and I don't drink!

 

[youwish2bme]

Barry I'd go ahead and see if they will order it for you and you can pick it up and the IR at the same time. If you don't need the Fan Clutch ask now if you can return it before it's ordered.. Could save you a day of waiting.. Dave..

 

[67HEAVEN]

Jack

traffic wouldn't drop 50%, maybe 35%, but not 50% !

Whatever you do, Barry, don't get a job. We'd miss you.

 

[BarryK]

Whatever you do, Barry, don't get a job. We'd miss you.

i'm going to have to get one to keep up with the expense of trying to keep this car running!
:ugh

 

[BarryK]

considered it........ told them i'll let them know tomorrow on the fan clutch. he said if i just let them know in the early morning he could have it by 11:30 tomorrow morning so it would only be a few hours

 

[vigman]

Barry...

You do know that there are different...versions of the temp sender.. they all call the same part # but the internal resistance IS different at different tempratures.. I got burned on this. and I had to get my new sender at ... auto zone.. TU-7 comes to mind.. and that different sender = a 10 degree drop..
I'll check my old postings.. I might have *****ed about this very same problem.

Vig~

 

[vigman]

Check this out

http://www.corvetteactioncenter.com/forums/showthread.php?t=26561&highlight=Temp