Good advice! Chin spoiler, fan and clutch, shroud are the right places to start looking.
Overheating problem - 81 vette
Thread Starter
4th Gear
Joined: Dec 2009
Posts: 4
Likes: 0
Overheating problem - 81 vette
Hi everybody I'm new to the forum, I've just bought a 1981 Vette, just joined the family!
As usual, I'm fighting against all those small issues like minor leaks and interiors...one thing that I'm really worried about is the overeating of my engine...it seems like it's slow to warm up, but then when idling/slow riding temp goes suddenly all the way up to 250+, then when driving around 30-80mph it goes down again to normal levels, and it stays low until I hit traffic or I stop completely.
Do you think it might be related to a faulty thermostat?
I've got edelbrok carb and intake with headers and sidepipes installed by the previous owner, maybe this puts additional streess on the engine...
Thanks in adv to anyone who will reply!
As usual, I'm fighting against all those small issues like minor leaks and interiors...one thing that I'm really worried about is the overeating of my engine...it seems like it's slow to warm up, but then when idling/slow riding temp goes suddenly all the way up to 250+, then when driving around 30-80mph it goes down again to normal levels, and it stays low until I hit traffic or I stop completely.
Do you think it might be related to a faulty thermostat?
I've got edelbrok carb and intake with headers and sidepipes installed by the previous owner, maybe this puts additional streess on the engine...
Thanks in adv to anyone who will reply!
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
Since temps. go down when at speed this is telling us that you are not moving air through radiator when ideling. Do you have the stock fan/clutch and shroud? Is coolant level correct? You will need to check for seals around and on top of radiator. These insure that air is sucked through rad. and not around it. This is what I would check first. Might be a good idea to check thermostat but is not sounding like it is the primary cause. Other members will help too. Welcome to the Forum these guys are the best. mds...
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Fan Clutch and shroud seals are the likely culprits if everything is still there. At speed on the road if it stays cool that tells you the air dam is probably doing its job and that the radiator is also probably doing ok. The T-stat sets the minimum temp, so its most likely good too. I would examine the radiator to shroud seals and the fan clutch to start, asuming the coolant level is ok. With the hood up, engine running and warmed up watch the fan and kill the motor, the fan should not turn more that 1 turn or so after the motor stops. If it even looks close replace the clutch.
Welcome aboard!
Welcome aboard!
Drifting
Joined: Apr 2008
Posts: 1,992
Likes: 56
From: Antioch IL
Welcome to the Forum. I would say this a problem with the Fan Clutch. i do not think if is the air dam because you say the problem is more notorious when in traffic. good luck and enjoy your new toy.
BY THE WAY ADD PICTURES!!!!! we love PICTURES
BY THE WAY ADD PICTURES!!!!! we love PICTURES
Last edited by larryg3; Dec 19, 2009 at 11:37 PM. Reason: added text
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5th Gear
Joined: Jun 2015
Posts: 5
Likes: 0
From: Tucson AZ
Burning Brakes
Joined: Apr 2013
Posts: 1,194
Likes: 109
From: Las Vegas NV
Make sure you got ALL the air out. Also, when the engine is warm, rev it up (3,000rpm+) and down and check to see if the hoses are collapsing.
You should see your overflow level rise when the temp goes up and lower when the temp goes down if the radiator cap is working properly.
You should see your overflow level rise when the temp goes up and lower when the temp goes down if the radiator cap is working properly.
5th Gear
Joined: Jun 2015
Posts: 5
Likes: 0
From: Tucson AZ
Make sure you got ALL the air out. Also, when the engine is warm, rev it up (3,000rpm+) and down and check to see if the hoses are collapsing.
You should see your overflow level rise when the temp goes up and lower when the temp goes down if the radiator cap is working properly.
You should see your overflow level rise when the temp goes up and lower when the temp goes down if the radiator cap is working properly.
Burning Brakes
Joined: Apr 2013
Posts: 1,194
Likes: 109
From: Las Vegas NV
Right so if the air was completely removed from the system, the overflow tank would rise as the pressure from the rising temperature expands the coolant. When everything cools down, the coolant gets pulled back in from the overflow from the vacuum in the system. Air screws all of that up.
Last edited by AboveTheLogic; Jul 21, 2016 at 12:54 AM.
Heel & Toe
Joined: Mar 2016
Posts: 22
Likes: 2
From: Norfolk VA
If you keep popping belts then more than likely its caused by either a bad water pump with a bearing and or your entire cooling system needs a good flush. My friends trans am was having similar issues without the belts. Gave it a flush and it solved everything. If it is your water pump i reccomend getting a flowkooler water pump this pump works wonders with my stock radiator.
Last edited by Matthew Manney; Jul 21, 2016 at 01:03 AM.
