L98 Cooling system.

[90steelbluevette]

When I first got the car, it would run at 193-200 ish and 230 max in traffic. After it got really hot here in GA (115* days) I noticed the car would heat all the way upto just before the 260 mark. I freaked of course, but the car never overheated. I checked the fluid level, it was fine.. I replaced the factory 195 t stat with a 160 to test it out.. still does the same. I noticed that coolent flows just fine, no trouble at all. The main cooling fan comes on, but did not see if the second fan will come on. But sitting in traffic, with the AC on, the car will still heat up higher than the 160 mark. It will go upto 230 with the ac on. Its been about 80-90* outside lately.

Also I have not set my idle yet. If that has anything to do with it.

I can't figure out what is going on! Any help will be great!

 

[redvett]

Do not touch the idle screw it will change the IAC counts and really mess up things. Have you cleaned the rad & condenser of leaves & trash? This is a common problem. Look under the front at the rad and see how much trash is there also remove the upper cover of the rad to clean the rad & condenser. Put the 195F thermostat back in so the ECM can run your engine correctly. A lower stat needs a different calibration to run correctly.

 

[90steelbluevette]

Hmm yes, I should wait for the chip before running the 160*. I touched the screw when I first got the car and replaced the IAC, so I need to run all that around. As far as trash, I cleaned it when I got it too (I have a 96 Trans Am WS6 before the vette- it happened to it too).

So let me go out and reset all of those.

I just drove the car for about 45min. Car still heated up, both fans are kicking in. And from the looks of it, I am still full of coolent. When on the hwy, the car does fine as long as I am doing a consistant 40mph or higher. Just when sitting for any length of time is when it will go upto the 250 mark. I drained the system when I changed the first t-stat, and refilled it with green 50/50 mix.

 

[muddywaters]

The Rad/Cond. area of my 88 was loaded, I couldn't believe the leaves, cig. wrappers, lottery tickets, etc. that was in there, it looked like a vacum cleaner bag, the rest of the car was super clean, check it..............................

 

[90steelbluevette]

Nice! Ok then I will. I just tried adjusting my TPS sensor.. and I dunno, but the maximum I was able to get the voltage in the idle position was .46 volts. When I tried to set the minimum air intake to 400rpm, I was not able to get the car lower than 1200rpm. It sounds like I have a air leak somewhere, but I have checked it all. Sounds like its coming from the IAC intake, that is, the IAC I just replaced and reset.

Screw this car, I am taking it to a shop. What a piece, the engine was replaced 7800 miles ago with a new crate motor. And the idle and all was just fine with the old IAC, but the old IAC seized and made it impossible to start the car without opening the throttle plates.

*Just took out the IAC and plugged it in outside of the TB.. the pintle does not even move, it does not move- it does not open or close. So it is bad. Also it was barely on there, took little to no effort to remove it. Guess I have to start there.

 

[redvett]

Hmm yes, I should wait for the chip before running the 160*. I touched the screw when I first got the car and replaced the IAC, so I need to run all that around. As far as trash, I cleaned it when I got it too (I have a 96 Trans Am WS6 before the vette- it happened to it too).

So let me go out and reset all of those.

I just drove the car for about 45min. Car still heated up, both fans are kicking in. And from the looks of it, I am still full of coolent. When on the hwy, the car does fine as long as I am doing a consistant 40mph or higher. Just when sitting for any length of time is when it will go upto the 250 mark. I drained the system when I changed the first t-stat, and refilled it with green 50/50 mix.

For where you live a 50/50 mix should get you down to -37-40F its way too strong. Heck i dont use any stronger than -22F here in Michigan. The more AF you use & less water the less heat transfer your going to have. Water is the best for heat transfer and adding AF to raise the boiling point to 260F is plenty. You may have the wrong intake gaskets since the engine has been changed.
The only way a IAC can be properly set is with a scanner and looking at IAC counts 15-30 in drive engine warm with timing,TPS set correctly. The idle speed will than be at what the Memcal is set for.

 

[90steelbluevette]

Hrmm, so basically I need to dump out my coolent and mix it 60% AF anf 40% water. I always thought the higher the water amount is the cooler it is. meh. I don't have a scanner , so looks like it is going to a shop after all.

 

[golfman2008]

 

[redvett]

Don't dump it just drain out some and add distilled water and check with a AF hydrometer.

 

[90steelbluevette]

OK, guess I will do that then. Such a sensitive little car, like a emo kid lolz.

Don't dump it just drain out some and add distilled water and check with a AF hydrometer.

So does that mean it needs to be 60% water and 40% antifreeze? Did I have it backwards?

I guess that is the only other thing that can possible be making it heat up eh? I even put in a manuel fan switch and it helps. Just ordered a chip for the car with the fans kicking on at 174*. I need to get the car to work good before next week. Starting a new job that is a 1 hr commute in sitting traffic.

 

[90steelbluevette]

Still~!!!!!

Well I changed my mix. I removed a 1 1/4 gallon of my 50/50 mix. And replaced it with 1 and 1/4 gallon of distilled water... then added a FULL bottle of Redline Water Wetter. Roughly that should sure as hell do it in keeping it cool, but she still overheats to almost redline mark.

Then I noticed I did not notice a sound missing, my cooling fans! They are not coming on and the fuse is not popped! bingo

 

[johnny80]

Cooling fans

My 88 had the same prob only the main fan didn't come on, just the second. I tested it by putting key in, turning the ac on and then turning the key (not starting it though) Fan did not kick in. bought a replacement fan at Auto zone and it did the trick. Install was easy, just had to take fan shroud off, and remove old motor and swap it out. Works great now. never gets past 195 even in summer.

 

[90steelbluevette]

yes, but its not the motors. Must the the temp switch. When I turn on the AC, the fans will come on. I wired up a manual fan switch and they will come on.

but now, my car is not charging the battery. So it is going dead. Wierd thing is the Voltage light just flickers. My voltage coming from my BRAND NEW battery is about 12.6 when charged. But the big thing is, when I turn on the car and check the voltage at the altenator, it is the same. I took the alternator to NAPA and they tested it, it came out ok!

I am about to start another thread about this, I did on a good note just get my new tuned chip for the ECU. Once everything is back in order that should pep it up a bit.

 

[geekinavette]

yes, but its not the motors. Must the the temp switch. When I turn on the AC, the fans will come on. I wired up a manual fan switch and they will come on.

but now, my car is not charging the battery. So it is going dead. Wierd thing is the Voltage light just flickers. My voltage coming from my BRAND NEW battery is about 12.6 when charged. But the big thing is, when I turn on the car and check the voltage at the altenator, it is the same. I took the alternator to NAPA and they tested it, it came out ok!

I am about to start another thread about this, I did on a good note just get my new tuned chip for the ECU. Once everything is back in order that should pep it up a bit.

Be careful when having a shop "test" an alternator....ask them if they're putting an appropriate load on the alternator. If they're not loading it, then it could "test" just fine but when you put it in your car it might fail under load. Some do load it, some don't.

Bill

 

[90steelbluevette]

Yes I hear that, I think the guy did not know what he was doing.

Correct me if I am wrong, but is the ONLY thing between the Alternator Battery connection and the battery the fusiable link then the jump start terminal? or does it run else where?

 

[geekinavette]

Yes I hear that, I think the guy did not know what he was doing.

Correct me if I am wrong, but is the ONLY thing between the Alternator Battery connection and the battery the fusiable link then the jump start terminal? or does it run else where?

I don't know about '90 without looking at a wiring diagram...but "typically" the battery connection runs to the starter, then up to the alternator.

 

[90steelbluevette]

I don't know about '90 without looking at a wiring diagram...but "typically" the battery connection runs to the starter, then up to the alternator.

I'll get under there and look. When I check the voltage at the Alternator, its the same as the battery - 12.6 volts, engine running or not. Something is messed up. Any clues as to where the 3 wire connector on the Alternator run too? I am looking at the diagram in the FSM, and looks like the battery cable goes from the atlernator, to a fuse link, then to the jump start block, then to the battery.

 

[90steelbluevette]

Ok,

I just looked. The battery connection to the alternator is working, its at the same voltage as the battery. The 3 wire connector is working too, it recieves the same voltage as the battery.

now going to test it with the battery connection off and see if the alternator is sending volts out.

*UPDATE*

Alternator Needs to be replaced. I tested all of the connections of the 3 wire connector, they all have the same voltage as the battery. The battery connector has the same voltage as the battery. HOWEVER, now the car will not turn over....

when will the crap end!

 

[90steelbluevette]

All clear:

Alright, took the alty back to napa. They gave me a new one- now all better!

Also, after installing my tuned PROM chip, no more overheating! good stuff. All thats left is the IAC valve being reset and the idle adjusted!

Thanks everyone for the help! Anyway to leave karma/feedback for members?

Ryan