C5 Water Temp problems... or computer?
Thread Starter
4th Gear
Joined: Oct 2009
Posts: 4
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From: Concord CA
C5 Water Temp problems... or computer?
My first post is a dousy... here we go! I bought my C5 used two years ago. The previous owner had done a performance reprogram and installed Borla exhaust.
History... several months ago, I ran the car through the car wash and after leaving both the water temperature gauge and digital read shot up to 250 by the time I got home. Later I got back in the car and every thing was fine. I figure something got wet and hosed the indication.
Current problem... the other night I did a major stereo upgrade and had the battery disconnected for several hours. Ever since the idle has been erratic. But the biggest problem is the water temperature. Idling in the driveway the car the temperature gauges will ramp up past 230 pretty quickly... and will peg the gauge driving around town... on the highway it's running dead nuts about 198. Also, it seems like the fans are not running properly!
Do I really have a water temperature problem or is something fubar in computer since I had the battery disconnect so long?
Thanks for any help!
History... several months ago, I ran the car through the car wash and after leaving both the water temperature gauge and digital read shot up to 250 by the time I got home. Later I got back in the car and every thing was fine. I figure something got wet and hosed the indication.
Current problem... the other night I did a major stereo upgrade and had the battery disconnected for several hours. Ever since the idle has been erratic. But the biggest problem is the water temperature. Idling in the driveway the car the temperature gauges will ramp up past 230 pretty quickly... and will peg the gauge driving around town... on the highway it's running dead nuts about 198. Also, it seems like the fans are not running properly!
Do I really have a water temperature problem or is something fubar in computer since I had the battery disconnect so long?
Thanks for any help!
Last edited by stanman7254; Oct 25, 2009 at 11:33 PM.
Thread Starter
4th Gear
Joined: Oct 2009
Posts: 4
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From: Concord CA
How do you pull the codes?
I did all the basic stuff that could have mattered from the stereo upgrade. I'm a championship winning drag racer, so diagnosing problems isn't new to me.
More info... I know it's not mechanical. The initial indication was exactly like a bad thermostat. The temp would run up and then drop instantly. I replaced the thermostat and still had a problem... temp ran up and hose was still cold like the pump was not pumping any water... an hour later, new water pump... problem still exist!
I did all the basic stuff that could have mattered from the stereo upgrade. I'm a championship winning drag racer, so diagnosing problems isn't new to me.
More info... I know it's not mechanical. The initial indication was exactly like a bad thermostat. The temp would run up and then drop instantly. I replaced the thermostat and still had a problem... temp ran up and hose was still cold like the pump was not pumping any water... an hour later, new water pump... problem still exist!
Last edited by stanman7254; Oct 26, 2009 at 12:05 AM.
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Assure the front of the radiator is clean.............C5s pick up lots of road crap..
Pull the codes.........
The C5 is nice in that it has the ability to let the DIY read the codes w/o a tech II or go to the dealership. I do all my own work
Pull the codes.........
The C5 is nice in that it has the ability to let the DIY read the codes w/o a tech II or go to the dealership. I do all my own work
Thread Starter
4th Gear
Joined: Oct 2009
Posts: 4
Likes: 0
From: Concord CA
I pulled the codes and just a couple miscellaneous ones from having the battery disconnect... door controls and low battery.
Would the fans failing to stage properly show up?
If there aren't any codes would you still take it in to a shop? I've exhausted all my tricks?
Note: It didn't seem to have the same problem this morning coming in though it did jump up to 220 while at a long light after running it pretty hard to see if the problem would persist.
Would the fans failing to stage properly show up?
If there aren't any codes would you still take it in to a shop? I've exhausted all my tricks?
Note: It didn't seem to have the same problem this morning coming in though it did jump up to 220 while at a long light after running it pretty hard to see if the problem would persist.
