AMC Eagle Den Forum

The Mighty 258 => Cooling System => Topic started by: Zoro on July 09, 2011, 09:37:34 PM

Title: Overheating at redlights
Post by: Zoro on July 09, 2011, 09:37:34 PM
I have an '84 Eagle Wagon, the engine and everything that bolts to it was replaced within the last 60k miles. She normally runs cool unless you're stopped at a red light or parked with the engine running. AC on or off does not make a difference. The stock gauge will go up to the white notch at the top end of the green and stay there until the car starts moving again. The outside air temp was about in the mid 80's when this was happening. What can I do to improve the performance of the cooling system? I'm pretty sure the radiator isn't factory but it does look older and does not leak.

Thanks for the help!
Title: Re: Overheating at redlights
Post by: thereverendbill on July 09, 2011, 09:50:44 PM
you could ither install and mechanical guage in the car or take one of those digital point and shoot thermometers and check the accual temp of the engine.  the stock gauge isn't all that accurate in my opinion
Title: Re: Overheating at redlights
Post by: Sunny on July 09, 2011, 09:58:48 PM
is your fan working? It sounds like a stupid question, but my room mate was complaining of the exact same thing, and I noticed that his fan was seized. Once he started moving, it shot down again.

Because it's overheating only while stopped, it suggests that the rad is flowing, but the fan isint pulling air.

I agree with thereverendbill, are you sure it's actually overheating? It could just be a faulty gauge.
Title: Re: Overheating at redlights
Post by: Jurjen on July 10, 2011, 04:59:38 AM
I would say that your fan is not running.
I have electric fans and the only time they switch on, is when I'm standing still.
Title: Re: Overheating at redlights
Post by: Whuntmore on July 10, 2011, 09:35:42 AM
Yup, that all sounds right to me, there's no need for me to even comment on this.   :laughing9:

Title: Re: Overheating at redlights
Post by: eaglefreek on July 10, 2011, 01:31:31 PM
My guess, like others, it's the fan clutch. I was having the same problem a year ago. I did the spin test and it seemed fine. After a flush and new thermostat it still ran hot at a stop. Installed new fan clutch and it worked great after that.
Title: Re: Overheating at redlights
Post by: vangremlin on July 10, 2011, 02:27:31 PM
Here's my $0.02.  Check the fan clutch first.  You should be able to tell if its good or not, if not go ahead and replace.  No sense adding a mechanical gauge if you can tell your fan clutch is shot.  Good luck.
Title: Re: Overheating at redlights
Post by: BenM on July 11, 2011, 03:51:02 PM
Check the clutch and shroud, they affect the idle cooling a lot. I'm not sure if you mean your radiator is new, but if it is not make sure there are no cool spots. warm the car up just until the thermostat opens, then turn the car off and feel if there are cool spots on the radiator.

You may also have gotten a poorly spaced or weak pump. They should have 7 or 9 fins, the 5 fin is right out. There is also a clearance between the fins and the pump body, and that gap can be too large in poor quality aftermarket or rebuild. Just a little in that gap can make a big difference in performance.
Title: Re: Overheating at redlights
Post by: Zoro on July 12, 2011, 11:28:33 AM
I'll take a look at all of that. Did the spin test on the fan clutch and it seems to be working properly, might just replace that anyway and see if it helps. Even if it doesn't there's one less thing to break later. Fan shroud is in place and intact.
Title: Re: Overheating at redlights
Post by: HappyPappy on July 13, 2011, 03:29:53 PM
You said everything was replaced, Did you get the right water pump??  Just a thought!!
Title: Re: Overheating at redlights
Post by: Hawk258 on November 06, 2011, 04:08:22 AM
I have to ask, I am not sure if anyone else has, but the fan shroud is still there right?
Title: Re: Overheating at redlights
Post by: carnuck on November 07, 2011, 10:28:59 AM
If the waterpump is the wrong direction it will cool when revved but not at idle.