Fan Clutch
Thread Starter
Instructor
Joined: Jan 2000
Posts: 138
Likes: 0
From: Fairfax Ca
Fan Clutch
I think my fan clutch is bad but I'm not sure. When I turn off the car the fan stops immediately - is that right? My car tends to overheat when I drive fast. If I slow down, it cools off, so I'm thinking the fan isn't turning fast enough. I have replaced the radiator and thermostat and it seems like this is all that is left.
Any ideas?
Any ideas?
Melting Slicks
Joined: Oct 2000
Posts: 3,023
Likes: 2
From: TEXASTEXASTEXASTEXAS TEXASTEXASTEXASTEXAS
St. Jude Contributor
Re: Fan Clutch (Denyce Codoni)
It should stop pretty quick. But even if it's going bad, it's going bad in a way that shouldn't make your car overheat. If it were freewheeling, that could definitely do it, but if it's freezing up, that just makes it make a lot of noise at high RPMs and waste gas.
JB
JB
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Fan Clutch (Denyce Codoni)
Sounds like your on the right track here. But a leaky hose or cap can lose system press and heat things up to. I like to replace all hoses and cap every 5 years as regular maintenance.
Those fan clutchs ain't cheap and are a normal wear item too. :eek:
Those fan clutchs ain't cheap and are a normal wear item too. :eek:
Racer
Joined: Jan 2004
Posts: 294
Likes: 0
From: cincinnati oh
Re: Fan Clutch (Denyce Codoni)
I agree about changing the cap and the hoses first, they are the cheapest things to replace. It sounds like the clutch is working properly. Usually they "freewheel" after the motor has stopped when they are bad, not in your case. The other thing to check is the seals around the radiator (rad. to shroud, rad. to support, support to hood, etc.). If they are bad the air will not flow through the radiator at speed, the faster you go the less % of air goes through the fins. I put $5 worth of window AC unit foam between my radiator and support and that took care of the overheating. Best fix is to ditch the mechanical fan for an electric one.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Re: Fan Clutch (cardo0)
If it were a faulty fan clutch it would overheat when slow and cool fine when fast. Check your belt condition and tension (even though a belt isn't making noise doesn't mean that it's griping). Check your lower radiator hose (higher-speed driving increases suction pressure and can collapse the lower hose) to make sure it isn't soft and can resist collapse. Check your ignition timing -base timing, vacuum advance, and centrifugal advance (retarded timing causes overheating). Check your ignition plug wires (cross-firing and misfiring can cause overheating at higher rpm). Check your carburetor jetting by reading your plugs (lean mixtures cause misfires that can cause high-speed overheating). Make sure that you have the lower air dam installed (Corvettes are bottom breathers and notoriously overheat at high speed if the plastic lip is missing on the lower spoiler assembly). Make sure that you have the proper shroud and that all the shroud seals are in place (you want all the air to go THROUGH the radiator).
All of these things can be checked without spending a penny, which is how you're supposed to do it. I would check the spoiler lip and the shroud seals first.
All of these things can be checked without spending a penny, which is how you're supposed to do it. I would check the spoiler lip and the shroud seals first.
Thread Starter
Instructor
Joined: Jan 2000
Posts: 138
Likes: 0
From: Fairfax Ca
Re: Fan Clutch (Denyce Codoni)
Thanks everyone. I'll check out your suggestions. I would hope that when the radiator was replaced the seals would have been checked, but one never knows.
Once I figure it out, I'll report back!
Once I figure it out, I'll report back!
