I am concerned about the temp of the engine. During normal operation, without the a/c on, it runs around 195 degrees. With a/c on it goes up to 235 degrees. The engine was recently overhauled, (only has 1000 miles on it) has a new water pump, new antifreeze, 2 bottles of "wetter water" and a 165 degree thermostat. I recently bought the car and have done all the work since the purchase. The only thing I didn't do was r & r the radiator. I appears to be relatively new and I believe it is a 3 row because it is 3 inches thick. Does anyone have any ideas if this seems right or not. Also when the a/c is on the engine idles really rough and stalls constantly.

 

What model year? Are these temp numbers when the car is sitting or moving? Have you had the ECM reprogrammed for lower fan cut on temps? Do you have the AUX fan option in front of the radiator? 225/235 were the factory settings for the primary and aux cooling fan temps

 

Check several thongs out first. Are you sure those are the temps? Verify it with an IR thermometer. Check the radiator for cold spots. Check the space between the radiator and the AC condenser for debris clogging up airflow.

 

I am pretty sure the temp is correct. I installed a new digital dash cluster and also a temp sender... I'll check the other things out...

 

Where is the dash gauge temp sender on most C4s anyway? There sure a lot of threads about this.
I was worried about temps in my 84' w/ a LQ9 until I realized the dash gauge gets its temp from the sender in the driver's side cylinder head port which reads around 210-220 when warmed up. But if I plug in my ODBII scanner and check the coolant temp sensor at the thermostat, it will be about ~190.

 

Why a new thread?
https://www.corvetteforum.com/forums...erheating.html
Clean your radiator meaning take it out if not done so already.
Burp and should not overheat

 

I guess an ODB11 is a code reader. The car has been modifided to the extent that a code reader will not work, something that the previous owner did does not allow it to work. I have Used Scott Hansen In Reno and TunerPro RT to reprogram the chip, however he never did tell me anything about the temp. Can I just move the temp sender from the head to the intake? after about 8 tries to program the chip and get it all right (?) I still have a problem with it idling. If I stop andpark for a few minutes, when I put it in gear it dies and takes several tries to get it going, and when the a/c is on it will not idle at all. It just dies... any ideas on these?

 

The discrepancy between what the gauge temp shows and what the CTS shows really isn't that big of a deal for daily use. The ECM only uses the CTS temp in it's calculations. I would not recommend moving the temp sender from the head to the intake. Just my 2 cents, I think the move is negligible and it's not going to truly give you any important different information.

It sounds like you have a case of the previous owner's mods causing issues. I've spent a year undoing bad work from my PO... Is it possible to back track and find out what the PO did that has caused the cars ALDL to not be functional? Off the cuff, I have a feeling whatever mod was done is causing your issues. Otherwise, it could be a slew of things, including: IAC, loss of communication between AC controls and ECM, bad sensor communications. If you can find a way to see what the ECM sees (through your ALDL), I suspect your problem will be blatantly visible.

 

I have call the PO numerous times and he will not return my calls... I have even tried to explain I just needed info on the can (on his answering machine) so at this point I am flying blind.... I am going to contact the chip programmer and see if can tell me anything about the temps,,, Thanks for your help....

 

Same situation for me, wouldn't return my calls. So I took my FSM wiring diagrams and started first by tracing wire by wire on all the ECM inputs/outputs. I found so many places where someone obviously did bad work. Sure it was a lot of work to do that, but I now know my car inside out and I have the peace of mind the wiring is safe and connected as it should be per FSM.

 

Money changed hands and he doesn't want to be bothered. Perfectly common. Kinda why I prefer to get a dealership to do the PDI before I give money. Otherwise, I pass. Car modified? Pass unless it is done by a reputable shop. I check compression and have a scanner to see all codes you have been trying to hide. And people wonder why I won't even look at a car if you don't allow a PDI by a qualified mechanic or at the very least, do a compression and leakdown test with a scanner.

 

I think we need more info-running hot is VERY common on a C4.

Have you cleaned the radiator? As previously mentioned, this means TAKING IT OUT OF THE CAR. Clean in front of the radiator as well, between the radiator and A/C you get a ton of crap trapped in there. Unbend bent fins. Flush the radiator both forward and back. Refill the coolant system and burp it. 99.999% of the time, this is all you need to do to have your car running cool. Then think about installing a grille over the air dam to keep that crap from getting back in there (I'm going to be doing a writeup of this very soon).

195 isn't a terrible operating temp-it's actually the factory thermostat, so if you have a factory tstat in there, you may just be running where it's designed to run. 230+ is a little more concerning but again I'm betting you just need to clean out the radiator and surrounding area.

Are those temps while sitting still or moving? Sitting still it could be a problem with your fans not coming on. That's also really easy to fix. There's a relay on the driver's side on the rear of the wheel well. That's the cooling fan relay. Ground the green wire while the ignition is on, and you should get the fan to come on. If it doesn't, check the relay and fan motor and fuse.

I'd recommend looking at those things before diving too much into bad wiring issues because it's almost certainly one of those things. Let us know.

 

Great advice, best to check several THONGS first. However, you might over heat now

 

I'm not 100% sure that's a typo, considering it's coming from Aklim...

 

I don't know why it was not mentioned before but new engines being "broken in" will generate higher than normal temperatures for the first 1000-1500 miles or even longer depending on the engine and how it was rebuilt.

Some C4's have a bad habit of running hot, 235* is not that bad for a Corvette in hot weather. You might want to check or replace your radiator cap and verify the connections to the overflow tank are all good. I replace my radiator caps every five years or so as they do wear out. When they wear out they can be real trouble.

Like mentioned earlier be sure that your radiator is clean between it and the condenser. Make sure that your cooling fans are working properly. Another point is the front air dam, if it is broken or missing the car will see higher than normal temperatures unless you are cruising on the open highway.

You are using "Water Wetter" and that is a great product that really works. I use it in several of my vehicles. What type of anti-freeze are you using? What ratio of anti-freeze to distilled water are you using? I like to use as little anti-freeze as possible in my coolant mixture, water transfers heat more efficiently so more water helps the transfer more heat. Anti-freeze used in higher than needed concentrations can potentially make your car run hotter.

Be sure that your engine has a good ground. There are several sensors that use the ground and if it is not grounded properly the dash and the ECM get faulty data. You can check/verify the engine's grounding by taking a multi-meter and reading battery voltage at the battery and then using the engine for the ground test. Simply apply the red wire to the battery Positive terminal and then touch the black lead to the engine on a solid metal surface. The voltages should be nearly Identical. If not you have a potential problem there.

I wish you the very best in solving this dilemma so you can get out there and put some miles and smiles in your Corvette!