99 M6 running hot
Thread Starter
Cruising
Joined: Aug 2003
Posts: 12
Likes: 0
From: North Highlands CA
99 M6 running hot
Engine never seems to run less than 195' with 210' to 230' the norm (80-90' outiside). This is with a/c off or on. Fan's come on at 225' then seem to go off too soon, around 218' Of course moving through the air helps but still runs over 200'. Have 44K miles, no leaks, change thermostat today (Autozone only showed OEM temp type listed other that the Hypertech t-stats at lower temps- 160' and 180') no difference. Radiator fins are clean. Noticed yesterday engine was pinging under load at 230'. Anyone seeing this to? I just bought this car 3 weeks ago and noticing more and more little things- 1st gear pop out, parking brake sucks.
Melting Slicks
Joined: May 2003
Posts: 2,851
Likes: 1
From: San Bruno Ca
Re: 99 M6 running hot (V-tail pilot)
DOn't fret too much about getting a lemon. C-5s do run hot and all the temps you mentioned are typical. This does not mean that it is ok, but it's normal for the weather you have. My suggestion would be to get a fan monitoring kit that regulates your fans to kick on at a lower temp or have your car PCM tuned to let your fans turn on at a lower temp. Installing a 160
thermostat does not mean your car will run at 160. All it means is that your car will never run cooler than 160 once it has warmed up. Installing a lower temp thermo only means that now you can have the fans kick on at e.g. 190 now for the low temp fan and kick off at when it cools down to 179. and then have the high temp fan kick on at 220 and kick back off at 209. This is just an example. :cheers: Oh, let me mention that 230 is too hot but as far as your fans kicking on, that's about right. When you start to get too hot, then turn on the ac at anything over 215.
[Modified by Scubanme, 12:58 AM 8/31/2003]
thermostat does not mean your car will run at 160. All it means is that your car will never run cooler than 160 once it has warmed up. Installing a lower temp thermo only means that now you can have the fans kick on at e.g. 190 now for the low temp fan and kick off at when it cools down to 179. and then have the high temp fan kick on at 220 and kick back off at 209. This is just an example. :cheers: Oh, let me mention that 230 is too hot but as far as your fans kicking on, that's about right. When you start to get too hot, then turn on the ac at anything over 215.
[Modified by Scubanme, 12:58 AM 8/31/2003]
Drifting
Joined: Nov 2002
Posts: 1,708
Likes: 2
From: IF YOUR BIG DOLLAR PROJECT DOESN'T RUN 9'S OR BETTER ....BURN IT ! SHUT YOUR MOUTH AND GRAB A LANE ! CHICAGO IL. -------- HOME OF THE FASTEST STREETCARS BARNONE !
Re: 99 M6 running hot (V-tail pilot)
Radiator fins are clean. Noticed yesterday engine was pinging under load at 230'.
Thread Starter
Cruising
Joined: Aug 2003
Posts: 12
Likes: 0
From: North Highlands CA
Re: 99 M6 running hot (V-tail pilot)
Actually I love the car- my first Vette, just bitching about some minor problems. Do any of the reflash program kits (Hypertech, etc)change the fan on-off settings in addition to the other things they do for performance? Otherwise I'll go with the lower temp t-stat to get the fans to cycle sooner. Thanks!
:chevy
:chevy
Racer
Joined: May 2001
Posts: 484
Likes: 102
From: Prescott AZ
Re: 99 M6 running hot (V-tail pilot)
Xtreme used to sell a kit that does both. It included a 178 degree Tstat and a simple add on wiring harness that plugs into the system near the battery and turns on the fans at 175 or so. Total cost is 200 bucks or so...a lot cheaper than the Hypertech or other programers that really don't do much for an M6. I used to see temps like yours until I added that kit and watered down my coolant and added a jug of Water Wetter from Pep Boys. Now I run at 200-205 around town (and it's a lot damn hotter here...105 today!) good luck, you got a great car IMO!
:)
:)
Burning Brakes
Joined: Jul 2003
Posts: 1,104
Likes: 0
From: "In a van down by the river" CO
Re: 99 M6 running hot (AZ99FRC)
220 is fine. Notice on your temp guage that 220 is in the center, obviously the normal operating temp for the C5's. Contradictory to old school opinions, all engines don't need to run at 180 to perform (this is more for peace of mind and the critical factor for performance is actually the oil temp). Manufacturers design cooling syatems to run warmer these days due to fuel injection systems and the need to meet current emissions standards. However, if it makes you feel better, try the system AZ99FRC referred to (still available through alot of retailers) and/or some Water Wetter.
I wasn't trying to yell, but trying to provide some insight and help. Good luck.
I wasn't trying to yell, but trying to provide some insight and help. Good luck.
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
Re: 99 M6 running hot (V-tail pilot)
A lower temp thermostat combined with a manual fan controller is a good idea. If you don’t want to go with the hassle or expense of installing a manual fan controller then you could check out the C5 Parts for Sale section and keep your eyes peeled for a used Hypertech. Total cost should be the same or less if you play your cards right.
As far as pinging under load at 230 degrees goes, that is not normal and indicates that you probably have some carbon build up in the combustion chambers. To cure this, you’ll need to do the decarbonization procedure. It’s pretty simple to do, just check out this tech tip: https://www.corvetteforum.com/techti...=212&TopicID=1
The parking brake needs to adjusted. You can try cycling the handle up and down a bunch of times, which will take out the slack in the cables. If that doesn’t do it then the only way to adjust the brake is to remove the rear rotors to access the adjuster as GM failed to include a slot in the backing plate for access to the adjuster.
Popping out of 1st gear might be just a linkage adjustment but could also be due to a bent shift fork or a bad 1st gear synchro.
As far as pinging under load at 230 degrees goes, that is not normal and indicates that you probably have some carbon build up in the combustion chambers. To cure this, you’ll need to do the decarbonization procedure. It’s pretty simple to do, just check out this tech tip: https://www.corvetteforum.com/techti...=212&TopicID=1
The parking brake needs to adjusted. You can try cycling the handle up and down a bunch of times, which will take out the slack in the cables. If that doesn’t do it then the only way to adjust the brake is to remove the rear rotors to access the adjuster as GM failed to include a slot in the backing plate for access to the adjuster.
Popping out of 1st gear might be just a linkage adjustment but could also be due to a bent shift fork or a bad 1st gear synchro.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
