Mike1950

The temperature gauge on my 1995 corvette seems to heat up extremely fast at slow speeds. It falls rapidly as speed increases. Is this normal? I was wondering if this is normal or should I have it checked. At normal speeds, the gauge usually stays in the 190's but at slow speeds it climbs rapidly. thanks for any input

Ericthewolf

2 things first Welcome to the forum.. and yes Lt1's are infamous for running hot. Around the 200-220 range in stop and go traffic.. If you want to change this you are gonna need two things one a lower temp thermostat. Preferably a 160 degree stat. Second something to change the temp at which your fans come on. This can be done a few ways. Manually like whenever your A/C is on the fans are on. Also you can buy a hypertech and use the portion that reprograms your computer to turn the fans on earlier. last you can have your computer reprogrammed with a pc and some programming software to do the same thing as the hypertech. Otherwise you gotta live with the high power stealing temps. :cheers:

1996man

i totally agree with the above post but thought i would let you know that i had the exact same problem a little while abck and i solved it yby simply adding more coolant/water to the resivior. i know this sounds simple but appreantly they are extremely sensitive about how much water is in there and how cool they run. the more water the cooler they run. if there is to much then it will boil it off and it will spill out. this is my strategy that works for me. hope you get your problem solved on e way or another

Mike1950

I appreciate the input and look forward to being part of the corvette forum. Again, thanks

R23HTC

Running fine at speed and heating up quickly at slower speeds. I'd say take a look at this:




[Modified by R94 LT 1, 9:03 PM 6/15/2003]

Corvette1996LT1

:iagree: With the post above
1. Check to see if the radiator is clean
2. Program the fans to come on sooner
3. Replace the thermostat

The first two I think would give you the better result. You can change the thermostat but when you’re in stop and go traffic it is still not going to take long for it to shoot right back up. GM has the first fan set at around 225 and around 240 for the second as the trigger temps to turn on. Fans off = Hot when your stopped on a hot day. You will need to get you a programmer to adjust the fan settings. I called the service department when I first got my car because I was running 190 driving around but, if I set at a light or got caught in traffic for a long time it would go up to 225, then I would hear the fans come on. Their remark was that it is fine we see them hit 230 and that is within spec. I was told the backup fan didn’t come on until 240!! I would look at programming and cleaning first. Hypertech makes a nice one and I’m sure there are a few others out there as well. Thermostat is not a bad idea but will not help much without the fan setting changed.
PS: WELCOME! :seeya


[Modified by Corvette1996LT1, 8:23 AM 6/16/2003]

FullShred

:iagree:

I had a plastic grocery bag lodged between the radiator and the condensor

sundbergjc

I have a 95 LT1 also and I'm experiencing about the same temps in Alabama. There is always a lot of message traffic on this topic and a lot of opinions. Here's mine after a lot of reading and emails: The cooling system on an LT1 is pretty sophisticated and also pretty sensitive. The radiator, because of it's position and airflow tends to pick up crude so it needs to be kept clean. Adding Redline Water Wetter will help some as it makes the thing more efficient. Reprogramming the fans to come on at lower temps or adding a manual switch will work but it means having them running all the time. The addition of a 160 thermostat does nothing except open up sooner. It has no effect on how high the temps can go once it's open unless by some miracle it allows more coolant to flow which is doubtful. If you read all the posts, those with 160 thermostats are also running the fans. I'll take some heat for these statements on the 160, but it's all just basic thermodynamics.
:yesnod: :yesnod:

Lone Ranger

Well sort of.

The Hypertech branded 160 tstat (actually made by Motorad) flows a little better than the stock 180 tstat. I did not believe it either until I installed one. With my stock 180, cruising steady on the highway in summer weather (above 90 F and humidity around 70%) the temp would never get below about 194 on the digital readout. With the Hypertech/Motorad 160 installed the coolant temp now drops to as low as 184 under the same conditions. Now, in slow traffic or stop and go, without programming my fans to activate @ 185/193 (Lo/Hi fan rpm) the coolant temps will as expected begin to rise and go all the way to 220 when the stock fan programming kicks the fans on. Right now I am experimenting and have the fans programmed to come on at 212/219 (Lo/Hi fan RPM) with the 160 still installed. Those fan activation temps are the two choices in my Hypertech PP+, not my free lance programming choice (e.g. LT1EDIT) or anything.

BowTieBlood

I have this exact same problem! And guess what it's a '95. If you have someone who can program your car or want to pay for a Hypertech Programmer then get a 160 stat and it'll help a lot. My '97 Trans Am never got above 200 with the stat in place and I'm in Texas so humidity and heat are terrible. I just ordered a Meziere water pump and stat for my car a couple days ago, I'll post about how it helped once I get it all put in.

JB666

Well, I've got a '95 too, and was experiencing these problems... But, I find that with about 60 seconds of A/C, the temp will go from 210 to 192 !! So, that's one quick way to get out of a 'bind'!!

But, will the Hypertech programmer ($350+!!) do anything?? I was reading about it in the Eckler's catalog over the weekend, and they were talking about the 'performance' gains... DOES IT??????

Jeff

BowTieBlood

I got one merely for the thermostat back when I had my '97 Trans Am. It surely helped shifting a lot and the ease of it's programming is nice. I paid $420 back then :cry

I'll sell you mine for $150 + shipping, but then you have to pay Hypertech their "small fee" to have it programmed for your Vette. I don't know how much the "fee" is though :rolleyes:

Lone Ranger

No, the Hypertech "engine power tuning" doesn't do much, I can atest to that w/ my '95. I just use it for the fan programming feature.

JB666

Wanna sell yours?

Atok

Normal for a stock '95. Mine does the same thing, radiator is clean and full.

The fans are programmed to come on at 226-228 degrees. If you drive in traffic with the A/C on the fans will run all the time and keep the engine cooler, but not as cool as when you're driving. You can either put up with it or reprogram your PCM to turn the fans on at a cooler temp. A cooler T-stat will only help if you have air moving through the radiator.

:cheers:

Corvette1996LT1

Lone Ranger,

Would you mind adding to your post on what fan speeds the programmer will let you set.

Do you control the turn off and turn on to the degree?
Is it like 4 or 5 preset temps that Hypertech has put in?

Thanks for any input I was thinking of getting on this year and was wondering how much control they give you on the fan settings.
Also are you running the 160 stat and if so do you have a problem in the winter months with it going into closed loop?

Again Thanks!!!

Lone Ranger

I have the Power Programmer Plus. When you hook it up and turn the key on it presents you with a series of questions one by one. You answer yes or no, and if you answer yes it then gives you options to choose from. You cannot change the options it gives you. About the fans, it asks you if you want to change engine cooling fan settings yes or no. Answer yes and it then tells you to press Y (yes) if you have a 160 stat installed or press N (no) if you have stock 180 installed. On mine it sets the fans to activate in sync with a 160 stat @ 185/193 (lo/hi fan rpm) and stay on until the temp drops to like 176 then they shut off. For instance if the coolant temp hits 185 both fans come on low rpm or 'quiet' mode. But if the temp continues to rise it will kick both fans into high rpm mode (hear them roar) at 193. Now, if you choose the 180 option it does not leave fans stock. It will only leave the fans at stock settings if you tell it No when it asks if you even want to adjust engine cooling fan activation temps. If you chose its 180 stat setting after telling it yes you want to adjust engine cooling fan temps it sets them to turn on in low rpm mode at 212 and high rpm mode at 219 (I'm not 100% sure the high rpm mode is set to 219 but I think it is, mine's not gotten that hot using the hypertech programming). So there you have the temps.

I am running the 160 stat, yes, and no there were no problems this past winter (midwestern winter) with closed loop. The LT1 goes into closed loop at a pretty low coolant temp, I've heard as low as 98 degrees and I've heard as high as 130 degrees, but the lower figure is probably closer to the truth because GM set it as low as practical to keep average emissions as low as they could. The myth of colder stats not letting the car get into closed loop are from the earlier days of the L98 motor when the closed loop switch over temp was much higher.

Hope this helps!

:cheers:

Lone Ranger

$180 + shipping takes it :yesnod:

Why? Because I've been wanting to get setup with LT1EDIT using my laptop and a cable to delve deeper into programming my car.

Corvette1996LT1

Lone Ranger

THANKS!!! That was the info I was looking for. I don't like mine running the temps that it does. I don't like seeing that 225 range and it does get hot in the summer here in Memphis. I hope to buy one soon.

:thumbs: :thumbs: :thumbs:



[Modified by Corvette1996LT1, 11:25 AM 6/17/2003]