[Z06] overheating at idle
Thread Starter
Instructor
Joined: Jun 2006
Posts: 130
Likes: 0
overheating at idle
Well I thought i figured it out, but it's come to haunt me again. The Z is overheating again, what happens is, when I'm stopped at a red light, the temperature will begin to climb. But when i start driving again it cools right down. I figured out that you can blast the heat and then the car will cool itself as well. I'm thinking my cooling fans are toast? Or maybe the fuse?
Any suggestions?
Any suggestions?
Race Director
Joined: Nov 2004
Posts: 15,678
Likes: 1,097
From: birmingham Alabama
St. Jude Donor '09 and '13
Well I thought i figured it out, but it's come to haunt me again. The Z is overheating again, what happens is, when I'm stopped at a red light, the temperature will begin to climb. But when i start driving again it cools right down. I figured out that you can blast the heat and then the car will cool itself as well. I'm thinking my cooling fans are toast? Or maybe the fuse?
Any suggestions?
Any suggestions?
Drifting
Joined: Jan 2005
Posts: 1,724
Likes: 0
From: Oil Country
Agreed!
I had similar issues with my car, temps would steadily climb when stopped. I checked th fan operation and fans would work individually when commanded but drivers side would shut off when high speed was commanded. Turned out it was a bad relay! I also pulled the rad earlier this spring and it was gummed up with dirt and grass clippings, blocking nearly a quarter of its surface area.
Check the fans and check the rad for debris!
I had similar issues with my car, temps would steadily climb when stopped. I checked th fan operation and fans would work individually when commanded but drivers side would shut off when high speed was commanded. Turned out it was a bad relay! I also pulled the rad earlier this spring and it was gummed up with dirt and grass clippings, blocking nearly a quarter of its surface area.
Check the fans and check the rad for debris!
Le Mans Master
Joined: Oct 2006
Posts: 7,484
Likes: 2
From: Dayton, OH HAWG: "this is Off Topic...it can get a bit north of care bears and strawberry shortcake in here"
St. Jude Donor '08-'09-'10-'11
Define overheating? What temps are you seeing?
I tend to agree that it's likely blockage or air in the radiator. Check the surface from under the car, and then check for air in the radiator.
I tend to agree that it's likely blockage or air in the radiator. Check the surface from under the car, and then check for air in the radiator.
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
My first thought and partially from experience, is that your radiator and a/c condensor are extremely blocked up with dirt and debris. Since these cars are bottom feeders they pick up an amazing amount of crap and dirt. If you've never cleaned them out before you will be amazed at the amount of junk you will find. It's a little bit of a job but what you need to do is to remove the radiator shroud and separate the a/c condensor from the radiator. Alot of stuff gets lodged in between. Then you need to thoroughly clean both units and I guarantee you your temps will drop. I actually one time had a McDonald's french fry container stuck up there. After reassembling another good idea is to install a screen across the opening where air gets sucked up to the radiator. This will keep alot of the stuff from getting up there without increasing your air temps. Good luck!
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Burning Brakes
Joined: Sep 2008
Posts: 939
Likes: 0
From: Clarksville TN
My car has climbed as high as 235. My 01 WS6 never got hot even at the track after a few hot laps. My Z06 makes one pass and it's 230*. Not sure what's up with that but I'll start with cleaning the radiator since it's at 75k and I bet it has never been done.
Thread Starter
Instructor
Joined: Jun 2006
Posts: 130
Likes: 0
i think it is the fans, overheating is anything over 88degrees celsius. Because it stays around there when driving but when stopped(therefore no more air circulation) It just climbs up.
It shouldn't be any part of the coolant, since I just had it flushed, as well I asked them to blow out the rad.
When you say fan relay, what part is this?
It shouldn't be any part of the coolant, since I just had it flushed, as well I asked them to blow out the rad.
When you say fan relay, what part is this?
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
As I mentioned in a previous post, you really need to get at that radiator to clean it. From my own personal experience, I've tried just blowing it out and you won't believe how much dirt will still be stuck in there. I had a similar experience and after a thorough cleaning the temps dropped quite a bit. It is a pain in the ***, but is worth the effort.
Melting Slicks
Joined: Aug 2000
Posts: 2,618
Likes: 5
From: Overland Park KS
i think it is the fans, overheating is anything over 88degrees celsius. Because it stays around there when driving but when stopped(therefore no more air circulation) It just climbs up.
It shouldn't be any part of the coolant, since I just had it flushed, as well I asked them to blow out the rad.
When you say fan relay, what part is this?
It shouldn't be any part of the coolant, since I just had it flushed, as well I asked them to blow out the rad.
When you say fan relay, what part is this?
Your radiator could be dirty but that isn't your root problem here because when you are moving the temps are fine meaning air is moving thru your radiator.
Good luck.
Thread Starter
Instructor
Joined: Jun 2006
Posts: 130
Likes: 0
hmm, i dont hear a fan kick on when i hit the a/c button. But when i leave the a\c running, its keeps it at 88 degrees celsius, but if turned off it will begin to crawl up.... I'm not sure how you can tell if one of the relays is blown or not?
Last edited by dkny_stylez; Aug 25, 2009 at 09:35 PM.
Racer
Joined: Sep 2009
Posts: 414
Likes: 1
From: CT
my car is an 02 z and has similar issues. If im crusing in 6th on the highway doing like 70mph generally under 2000rpm i will notice temps are like high 190s maybe 203 at most...but if im driving in town and then get stuck in traffic they start to climb to 215-230 i guess im going to check my relays as well. I checked my radiator months ago when i installed my vararam and pulled out any large junk but there wasnt to much to be honest.
Race Director
Joined: Aug 2006
Posts: 12,545
Likes: 13
From: Colorado
St. Jude Donor '16 thru '26
This is from the GM manual, and is why I reprogramed my fans to come on sooner.
Cooling Fan System Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
Cooling Fan System Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
