Overheating on Hwy
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
You might be surprised,if 30% of the crosstubes are plugging up and the flush cleans them out you might be back in business.
If you take the radiator to a shop they will remove one of the end tanks and run a flat "rod" through each tube and clean them out, hence the term "rod out".
If you take the radiator to a shop they will remove one of the end tanks and run a flat "rod" through each tube and clean them out, hence the term "rod out".
I had the same problems a few years ago, changed the water pump, changed the thermostat ( 180°F ), changed the fan clutch ( pretty expensive part
) : nothing new, it was still overheating ( 210+ °F ).Then I finally bought a new radiator, and since this day, the water temp is always between 185 and 195°F, never higher, even in Summer with 95°F air.
Last edited by 73StreetRace; Jul 6, 2009 at 04:35 AM.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
you now counted out thermostat and you counted out lower hose.
fans are for idle cooling so its not that
airflow is for cruise cooling so could be that.
so............
i dont think you replied to elleybay about your air dam. after banging it on a few driveways it can end up scooping very little air. if this is okay and you have checked your timing then dewitts is the answer for you my friend.
fans are for idle cooling so its not that
airflow is for cruise cooling so could be that.
so............
i dont think you replied to elleybay about your air dam. after banging it on a few driveways it can end up scooping very little air. if this is okay and you have checked your timing then dewitts is the answer for you my friend.
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 1,028
Likes: 1
From: SOUTH ELGIN IL
I'll have to check out the air dam today...
Can anyone post a pic or two of their Dewitt's w/ dual fans installed? Thanks.
Can anyone post a pic or two of their Dewitt's w/ dual fans installed? Thanks.
Last edited by Dantana; Jul 6, 2009 at 11:17 AM.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
i dont have a pic but in the time that it took you to ask for someone to post one you would of had one with a search..there is over 1000 pics on here of dewitt radiators and fans. i would be confirming your temp gauge with a another mechanical gauge as well.210 is too hot,240 is danger.. you should never crack 195
mech temp gauge -$ 30
dewitt rad - $ 495
its your call
mech temp gauge -$ 30
dewitt rad - $ 495
its your call
Thread Starter
Burning Brakes
Joined: Apr 2007
Posts: 1,028
Likes: 1
From: SOUTH ELGIN IL
I took a hard look under the front end yesterday after being away from the car for awhile and upon evaluating I see what appears to be an air dam spoiler from a '68-'72 and not the '73-'79 (much larger) one that I should be running for my '74. I'm still figuring this car out and thinking that maybe the PO put an aftermarket front end on it with this set up ormaybe just the wrong spoiler.
Does anyone have a pick of a stock '74 set up that I can compare mine to?
Does anyone have a pick of a stock '74 set up that I can compare mine to?
Instructor
Joined: Aug 2003
Posts: 104
Likes: 0
From: Newfane NY
I have the same problem!!! Just started tho.I replaced my fan clutch due to noise, lost the noise but got the wrong one and highway speed overheat showed up!!!
Check out this link!!! http://www.haydenauto.com/Installati...s/Content.aspx
and consider the thermal type (with the spring) and heavy duty version.
Not just for idle as under hood temp of approx 170' should engage.
Also the heavy duty cooling has a different ratio for fan speed!!!
I'm getting mine later today and will let you know if it does make a difference.
Instructor
Joined: Aug 2003
Posts: 104
Likes: 0
From: Newfane NY
Update!!!
As with all problems, I took time to check, 'JUST FOR GRINS'
I DON'T have the spoiler 'Front air air dam' even tho I just changed the fan clutch, so that is also a contributing factor!!!!
Going to install one as soon as it comes on my next parts order!!!!
(Pic to follow)
I DON'T have the spoiler 'Front air air dam' even tho I just changed the fan clutch, so that is also a contributing factor!!!!Going to install one as soon as it comes on my next parts order!!!!
(Pic to follow)
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Melting Slicks
Joined: Jul 2006
Posts: 2,286
Likes: 487
From: Salmon Arm, BC
1. Get the correct air dam
2. Get some cleaner and run it through the rad for a few days, then flush and replace coolant
3. Get an air hose and methodically blow out the rad....lots of crap gets lodged inbetween the fins (much easier if you remove the rad)
4. Ensure that your fan shroud is in good shape (if its not fix it)
These thing along with what you've done already should fix your problem. All easy and cheap things to check before you spend a bunch of money on a new rad.
2. Get some cleaner and run it through the rad for a few days, then flush and replace coolant
3. Get an air hose and methodically blow out the rad....lots of crap gets lodged inbetween the fins (much easier if you remove the rad)
4. Ensure that your fan shroud is in good shape (if its not fix it)
These thing along with what you've done already should fix your problem. All easy and cheap things to check before you spend a bunch of money on a new rad.
Burning Brakes
Joined: Jul 2006
Posts: 1,108
Likes: 0
From: Sebastian Florida
If it's not overheating when sitting, the fan isn't the problem, and the radiator probably isn't either. The magic number is about 45 MPH. The air will go under or around the radiator at higher speeds.
210 is a little high, so cleaning the radiator would probably help.
210 is a little high, so cleaning the radiator would probably help.
Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
