High Temp Problem w/3" Cowl Hood??

John Temple

Registered User
I have a 91 SC with a 3" Cowl Hood from American Sports Car Design. The problem I am having is that in traffic and stopped the car runs very low on the temp. gauge with the A/C on but when I drive on the freeway above 50 MPH the temp slowly rises to about 3/4 on the temp gauge but doesn't overheat. I have a griffin radiator so thats not the problem. I suspect I am not getting enough air into the radiator at those speeds? Any suggestions on a fix would be greatly appreciated.
 
I suppose that the vents on the back of the hood are letting in air at highway speeds and therefore reducing the airflow across the radiator. I also have this hood, but have yet to install it. I will try and remeber to keep an eye on my temperature after the install (which won't happen until next year).
 
I have the same problem in my '91 every summer. I hunted and hunted for the source of a cooling problem and never found one. I finally attributed it to the dog days of August when 100+ temps and high humidity make the cooling system less efficient overall; it just can't keep up, which is why it starts to run a little warm on the highway. City driving gives the car a chance to "rest" at stop lights and slower traffic. I replaced the stock thermostat with a 180 degree unit and will probably go to a 160 degree thermo next summer.

As long as the temp stays consistent, albeit higher than you may like, you should be OK. If you had a problem the temp would climb steadily until the car overheated.
 
I had thought of that and made cover panels at the rear of the hood and they didn't make any difference? Does the chin spoiler need to be made larger and I wonder if the front of the hood needs a seal?
 
I INSTALED A FRONT SPOILER AIR DAM FROM A PONTIAC GRAND AM, IT COST 16.50 AT DEALER. ABOUT 1 INCH LOWER AND 8 INCH WIDER, PLACED MY OLD ONE UP IN BETWEEN NOSE PANNEL AND RADIATOR TO FILL THE GAP IN THE RADIATOR CORE SUPPORT.NOW MORE AIR GETS TO RADIATOR AND POWER STEERING COOLER AND TRANS COOLER.EEC TUNER IS SET TO TURN ON LOW SPEED FAN AT 186 DEGREES AND HIGH SPEED FAT 189 DEGREES, ON REAL HOT DAYS I HEAR HIGH SPEED FAN AS IT PULLS A LOT OF AIR BUT ONLY FOR ABOUT A MINUTE AND A HALF OR TWO MINUTES AND TURNS BACK OFF. MY TEMP IS ALWAYS BETWEEN 180 AND 189 DEGREES WITH STOCK RADIATOR. EEC TUNER IS THE WAY TO GO IT GIVES THE FANS TIME TO REST BOTH FANS TURN ON AND OFF AS NEEDED I USE TO HAVE A SWITCH TO OVER RIDE ONLY THE LOW SPEED FAN AND THAT WORKED OK BUT IT WOULD HAVE MY FAN ON ALL THE TIME AND NOT REALLY NEEDED TO BE.
 
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I agree about the tuner, but why do you have to yell about it, LOL
 
mine looks a little different, it is more like the factory one and is about i inch lower and 8 inches wider than the stock one! it is GM part # 22635885 and cost 16.60 plus tax.
 
my 92 SC had one and i used it to fill the gap between the nose pannel and lower radiator core support. the grand am air dam fit in place of the factory super coupe air dam. and the holes lined up with a little enlargement of a couple of them. added two extra to stiffen up and hold the correct angle for extra air directed to the radiator and trans cooler.
 
92_coupe:

I was wondering how much ground clearence you had once you installed the new air dam. Bob had mentioned that he had 4" on a stock hieght SC. I'm afriad that with my 1.5" drop, it would be way too low for me. Thanks,

Thomas
 
New ride height

I did some initial measurements and found with the 1.5 lowering springs you will have 3.25 inches clearance with the new spoiler. Not bad, just watch the high curbs! John
 
my 92 non lowered stock size tires measures 6 1/2 inches of clearance it has been over several speed bumps, but i switch on the firm ride like i use to do with the other spoiler. i learned when i first bought this car that trick helps even with the back ground effects clear the speed bumps in parking lots. no trouble with this new spoiler yet butt i havent been four wheeling yet LOL !! one thing i forgot to say is that i removed the cover under the car that was mounted to the sway bar and crossmember to let the extra air that gets through the radiator out ! also i have a new 160 degree thermostat with a used with life time warranty hypertech chip i would like to sell now that i went to eec tuner, i found it works good with 180 degree. it is a thermo master that has very aggresive timing and fuel curves. 1991-1992 super coupe with aod trans !
 
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Firm mode reduces the rebound in the suspension thus it's less likely to bounce so much that it compresses the shocks enough to have the front touch the ground.
 
OK John, I think I have your answer for you. The reason you are over heating is the cowl area is a high-pressure area. This forces air into the engine compartment from the windshield reducing the pressure differential between the front and rear of the radiator. This is the key to airflow through the rad. If you cover the cowl with some cardboard and duct tape I am sure you will find that your temp’s will return to normal.

Jeff
 
Mike8675309 said:
What stock one? On the Grand Am, or the SC? I've never seen one on my car.

The stock T-Bird piece for 89 - 93 is a E9SZ-63001A06-A, many cars are missing these ... I suppose they can get torn off on parking curbs, etc.


cheers
Ed N.
 
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