My C5 is heating up...
Thread Starter
Advanced
Joined: Nov 2007
Posts: 84
Likes: 1
From: San Juan Puerto Rico
My C5 is heating up...
So I got brave and decided to undertake a major upgrade on my Vette, which is way over my knowledge level on car mechanics. I pulled off a heads and cam swap, changing and/or upgrading many other components, such as the oil pump, timing chain, damper, a/c compressor, all new heads components and many other parts and tasks. So far most of what I've done has been right on, but made some mistakes. The first one was that I didn't tighten the damper correctly which lead me to upgrade to a Super Damper that wasn't needed, and when I wanted a different look I installed aftermarket aluminum fuel rails which my Vetted didn't like at all and after tinkering with the fuel system I reached the conclusion that the OEM fuel rails had to come back on.
This brings us to my new problem. Now that it's starting and running like new the engine cooling system isn't working. I took it out yesterday for a test run after installing back the factory fuel rails and when I returned home temperatures were over 220 degrees. I have a good idea on how to troubleshoot it but I would love to get some advise on how to really do it right. Please help!
This brings us to my new problem. Now that it's starting and running like new the engine cooling system isn't working. I took it out yesterday for a test run after installing back the factory fuel rails and when I returned home temperatures were over 220 degrees. I have a good idea on how to troubleshoot it but I would love to get some advise on how to really do it right. Please help!
Racer
Joined: Apr 2009
Posts: 488
Likes: 2
From: Myrtle Beach SC
Did you refill the coolant system in accordance with the factory service manual?
Have you looked at the radiator to see if there is dirt or debris trapped in the fins?
FWIW, 220 isn't hot. May be hotter than you would like, though...
If you haven't already done so, fill and bleed the coolant system using the service manual procedure. Check you radiator and A/C condenser for dirt and debris. Clean it out using low pressure air and/or a vacuum cleaner.
You said you had some ideas for troubleshooting...what are they?
Have you looked at the radiator to see if there is dirt or debris trapped in the fins?
FWIW, 220 isn't hot. May be hotter than you would like, though...
If you haven't already done so, fill and bleed the coolant system using the service manual procedure. Check you radiator and A/C condenser for dirt and debris. Clean it out using low pressure air and/or a vacuum cleaner.
You said you had some ideas for troubleshooting...what are they?
Burning Brakes
Joined: Nov 2013
Posts: 1,036
Likes: 119
When does the cooling fan kick on on these things? Isn't it at like, 230 degrees or something? Mine regularly goes up to 230 when I'm idleing, as soon as I start moving, it cools right back down to 180 or so.
Drifting
Joined: Oct 2002
Posts: 1,335
Likes: 76
From: Bedford Va.
Did you upgrade injectors and has it been tuned yet?
these are the right items to check.
these are the right items to check.
Did you refill the coolant system in accordance with the factory service manual?
Have you looked at the radiator to see if there is dirt or debris trapped in the fins?
FWIW, 220 isn't hot. May be hotter than you would like, though...
If you haven't already done so, fill and bleed the coolant system using the service manual procedure. Check you radiator and A/C condenser for dirt and debris. Clean it out using low pressure air and/or a vacuum cleaner.
You said you had some ideas for troubleshooting...what are they?
Have you looked at the radiator to see if there is dirt or debris trapped in the fins?
FWIW, 220 isn't hot. May be hotter than you would like, though...
If you haven't already done so, fill and bleed the coolant system using the service manual procedure. Check you radiator and A/C condenser for dirt and debris. Clean it out using low pressure air and/or a vacuum cleaner.
You said you had some ideas for troubleshooting...what are they?
Thread Starter
Advanced
Joined: Nov 2007
Posts: 84
Likes: 1
From: San Juan Puerto Rico
I'm going to find the filling procedures in the service manual and follow the instructions. After I did the cam swap I just poured antifreeze into the reservoir without doing anything other than a regular fill up. It seemed strange that I drained almost three gallons of antifreeze and when I filled it back it took less than half of that. I surely did it wrong. I hope this is the cause of the problem. I had been looking into checking the fuses and relays governing the fans. I didn't do it today for lack of time. Now I have more possible causes. I finished the engine upgrades over a year ago but since I was doing paint and body work I had to wait until now to try tuning. Every time I've been at the dyno I've had to return home with my limping Vette with a new diagnosis of something not letting the tuner guy do his job.
Thread Starter
Advanced
Joined: Nov 2007
Posts: 84
Likes: 1
From: San Juan Puerto Rico
Relay number 43 was the culprit. Got it replaced and the fans are ok now. Two of the holes were the pins go into are burnt, the other two are ok. I'm a little worried with the burnt holes and I wonder why it actually got burnt.
Team Owner
Joined: May 2001
Posts: 87,337
Likes: 1,590
From: Western NY
I'm going to find the filling procedures in the service manual and follow the instructions. After I did the cam swap I just poured antifreeze into the reservoir without doing anything other than a regular fill up. It seemed strange that I drained almost three gallons of antifreeze and when I filled it back it took less than half of that. I surely did it wrong. I hope this is the cause of the problem. I had been looking into checking the fuses and relays governing the fans. I didn't do it today for lack of time. Now I have more possible causes. I finished the engine upgrades over a year ago but since I was doing paint and body work I had to wait until now to try tuning. Every time I've been at the dyno I've had to return home with my limping Vette with a new diagnosis of something not letting the tuner guy do his job.
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Race Director
Joined: Jan 2007
Posts: 18,643
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From: Norman Oklahoma - The Only State in the Union with no Blue Counties!
Sounds like you've got a HUGE air pocket in the cooling system.... When the engine is COLD, pull the cap off the reservoir, start the engine, let it run for several minutes, and let the air escape. You'll know, as the coolant level in the reservoir will drop, and you'll need to top it off.
Best bet!
Melting Slicks
Joined: Nov 2009
Posts: 2,922
Likes: 219
From: West Branch, MI
I might add here that virtually every thread I've read that have had heads/cam installed, the user has changed the thermostat. Since the OP is in PR, I'd suggest going to the 180 at a minimum. Easy to do, not expensive. Will help the cooling on the modded C5 for sure.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Sent from my DROID RAZR using IB AutoGroup
Melting Slicks
Joined: Nov 2009
Posts: 2,922
Likes: 219
From: West Branch, MI
It's all relative. It does help a little but not without tuning. And if you install H/C, etc... you must get a tune. A competent tuner knows how to tune the fans. My H/C/I install was tuned with a 180 thermo and I seldom get above 200-205, even when idling. Hottest of days with AC going, stuck in traffic, I might see 210-215.
Race Director
Joined: Mar 2008
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From: Rio Rancho NM
Team Owner
Joined: May 2001
Posts: 87,337
Likes: 1,590
From: Western NY
Drifting
Joined: May 2007
Posts: 1,547
Likes: 210
From: Huntersville, NC
is this what you are looking for?:
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).
Normal driving with driving speed that flows sufficient air across the radiator with the AC off, the coolant temperature with a factory thermostat is 190°F, The fans will be off. The factory setting will not let the first cooling fan come on until the coolant reaches 226°F.
Unless you tune the fan start points, this is the factory setting. One thing that will mess you up is dirt in the radiator, or a baggie sucked up and blocking the radiator air flow..
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).
Normal driving with driving speed that flows sufficient air across the radiator with the AC off, the coolant temperature with a factory thermostat is 190°F, The fans will be off. The factory setting will not let the first cooling fan come on until the coolant reaches 226°F.
Unless you tune the fan start points, this is the factory setting. One thing that will mess you up is dirt in the radiator, or a baggie sucked up and blocking the radiator air flow..