Ozzysezit

I just bought a C5 in December. Today I drove it down the freeway and home again (60 miles round trip) It seems to run around 180-190 degrees on the open road, but in town in stop & go traffic and my luck of hitting every single red stop light in town it seems to get up to about 220-230 but then will come back down to 200 or so.
Also, if I park and turn the car off and the temp. is around 220, I dont hear the fans running. Is this normal for the C5?
The car only has 72k miles on it, so I wouldnt think the fan motors would be bad, and if they were, I would think it would go alot higher than 220-230 when sitting at the ever loved and never ending red light.
I did read in a car magazine that under race conditions these engines can handle 230-250 degrees, but Im not racing.
I really dont feel like putting a $6000 motor in this car when its only got 72k miles on it.

Any tips or help would be much appreciated.

Z06ster

When I had the stock radiator, I was doing 220-225 on a hot August summer day in Southern California idling at a street light.

The stock radiator is an absolute joke and I don't know what GM engineers where thinking. I think it is a mere inch thick at most.

One thing you can do is get aftermarket radiator thermostats at a lower temperature. I believe they make them at 160 and 170. The best solution is a DeWitts radiator.... but they're not cheap, but worth the money. On a hot summer day now idling, I don't go above 200.

fishbust

I didn't like the oil going over 200, it smelled bad. It is just too hot.

You could put a 160 t-stat in it. Mine is so much better now.
You can also have your pcm programmed to bring fans on earlier.
Those 2 things should hook you up and then do an oil change.

James2002z06

You can have our fans adjusted to where they kick on sooner , I know how u feel though I've seen mine get up to 220 , I changed out the raditor with an aftermarket .. The design is terriable the Z28s have the same problem there just isn't enough air flow

calvins

Thread on this just the other day.....

http://forums.corvetteforum.com/c5-g...gine-temp.html

MG RED 99

To the OP, it seems as though your car is running normal and as intended by GM. Something you might want to check though is if the radiator fins are clean and debris free. Since the C5 is a bottom breather design they tend to suck up a lot of crap between the radiator and radiator shroud cover. This can cause less airflow through the radiator and increase temps. The LS1 does normally operate at those temps and you shouldn't be worried about any engine damage. If the temps get to high you will get a check engine light at which point you would need to shut the car off immediately and have it checked. Another area to check would be when was the coolant last changed.

There are many ways of altering the engine and computer to run at lower temps if you are still worried about it, and many here can offer advise on that if you need it. Some will advise against it, but it's a decision you will have to make for yourself. Talking with a reputable tuner who has a lot of experience with these engines may also help give you some piece of mind. I'm no expert and have always relied on my tuner for the best advise when it comes to my engines longevity.

I personally run a 160 thermostat and have had the fan settings changed to run cooler. Also added new coolant with 2 bottles of water wetter to the coolant. My engine has other modifications as well such as a cam and headers.

Sids04

As stated, check the radiator for accumulated debris.. Mine was loaded with debris.. I also used HP tuners to lower the temp for the fans to kick on ... Around town in August the max is usually 205 for me

PETE O.

A Cool-It II from SacCityCorvette took care of all my cooling worries.

DarkBlueC5

doesn't take long to get to 220 when sitting and idling. switch on the A/C to activate your fans and it'll drop 20 degrees pretty quickly

onlyavette

MG RED 99 is spot on in my opinion.

For a stock and even slightly moded engine the stock radiator is more than capable. I cleaned the debris out of the condenser and the radiator, installed a 160* t-stat and adjusted the fans accordingly. I too live in SoCal. and drive in stop and go and city driving. I rarely see it get over 195* and it runs at about 180* + or - 3* at freeway speed. I would clean everything up and try a lower t-stat before a spent money on an aftermarket radiator.



Good luck.

Evil-Twin

NO, it is perfectly fine

frenchsquared

GM says it is good so by all means it is. They are gods and do everything perfect.

In reality... it is fine to run these engines at 220. I personally don't like it. Heat is not a good thing.
I adjusted the setting and cleaned the cooling system on my C4 so it staid around 190.
I am sure you can do something similar on the C5 and I will be if it is needed on mine.

I always try to keep my engines under 190... personal preference.

I agree 100% with onlyavette

but remember GM says it is ok and we have to make sure we do everything GM says.

spdislife

Evil-Twin

This guy must have grown up listing to his grand father and how he maintaned his 60 buick...

FYI the sweet spot of an LSX motor is designed to run between 190 and 220F coolant and the sweet spot for oil is above 210. The LSX motor was the first to be benched marked at 200,000 miles.. we achieved this with the right spec of oil additive to protect this motor and to control shear .. HP is achieved through design which includes extremely tight clearances. Running cool oil below 190 will indeed starve off lubricity in the top end. This is not your grandfathers Buick. These cars see 300K and 400 K plus because we know what we are doing and developed a New age engine using a pushrod motor...this is a tribute to Dave Hill's vision on engine design and accomplished through dedicated engineers and delivered at the hands of John Juriga.
I often say to newbies to be careful who you listen too on this forum. Unfortunately there are way more legends in their own mind here than people who actually know their stuff.. the good news is there are a good amount of people here who are experts in their particular area of expertise.. You have an electrical issue, the first name that pops up is Bill Curlee, we have a bunch of great tuners, engineers and professional mechanics in this forum, we have guys like Ed Bon ( patches ) who is also an engineer who can help most people with most things mechanical And he does it with grace and kindness. Something that eludes me at times. Especially in the face of people who claim to know something but in reality do not and what makes it worse is they want to argue. The trick here is know who to listen too and who not to listen too... here is a hint.. there is a guy in the thread that no one should be listening too. See if you can figure out who that might be.
Bill aka ET

Ozzysezit

Well E.T. If it aint broke, I wont fix it!
This is my first newer Vette. My first one was a 69 that the guy thrashed beyond repair. Back then, if a car got over 195 degrees or so, there was cause to be worried.
If you guys that know your stuff say this car should run where she is running, I will leave it be.
I was just concerned because I have never had a car that ran at this temp. range.
I will, by all means, take it to the Local Corvette people and have oil and Coolant changed though. just to be on the safe side. Oil thing says there is 57% oil life left, but summer time is coming up so I may as well have everything done at one time.
The Previous owner supplied me with all the maintenance records on the car so I know dang well it was very well taken care of.
I will heed the advice of all and make sure the radiator is free and clear of any debris. While I am at it, I think a K&N Air filter may be in order.
Thank you all for the comments.
As a newer Vette noobie, I get a little worried about issues. But it is great to know I can get on the Forum and get the answers I need!

PryOpenUr3rdEye

220 is ok

Glock 23C

Thx for the straight talk ET. The heat thing was something that had me a little concerned while driving in Minnesota's heat and humidity the past 2 yrs. I will be leaving things as is.

KALAWAY

My 2001, which I have had for 15 months and has 86K miles, also heats up to 220 when driving in slow traffic. The repair tech at the Chevy dealership told me that is normal for a C5. I was a little worried too. I am used to 190 or so. I'm not much of a gear head so I won't be changing out the radiator anytime soon. Hopefully the dealership won't have to either.

Evil-Twin

Many people who come here are concerned about higher temps of this motor.. only because this is not a cast iron motor, and its designed to run hotter to get the most out of the engine and to think with this design we increased the longevity of the motor from 100,000 miles to 200,000 miles. although I have many member check in with me about how great their 200K, 300K, and 400K C5 are running. You have got to let that old 80's mentality go. not to get confusing about cold vs. hot, it is true you can get more ponies from a colder engine but at the expense of longevity. From a longevity point of view hotter is better than colder. Tuners can easily get more HP out of this motor, they don't care that it might cost you 50,000 miles of longevity, its there job to show you a gain in HP. not to preserve the engines designed integrity.
To ease your concern just go look where the red line is on your temp gage. Many road racers run their car on the track at 260 F with no ill effects.

OKZ06

Jeez Evil-Twin quit acting like you had a part in designing this car or something, just kidding i searched for this question the other day and found another one of his posts referring to this never need to go any further when you show up.