I have a Fresh Hydraulic roller motor build that seems to run hotter on the highway, The car has a all new cooling system, Fbody Rad, Chysler Fans , Casper harness , New water pump and a 165 stat.. My car seems to run at about 180-190 on hot days and more so when doing highway speeds.. Once I get into traffic the car seems to cool down.. I'd figure it'd be the other way around. Is it possible a brand new water pump is the issue.
Running on the hotter side..
- Thread starter Justin85
- Start date
John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
Run a jumper wire so your fans are on all the time and see what happens on the highway.
John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
You might also need to burp the cooling system. It happens. You loosen one of the hoses at the heater core and as soon as coolant starts spewing out, that should have pushed all the air out - its the high spot in the system. It's a little messy but with a new system you never know.
My car also runs hotter on the hwy. Today it was 91 degrees out. I was going 75-80 with ac on and coolant temp was 213! When I got off the hwy, temp dropped to a frigid 199! From past experience temp usually stays under 200 on the hwy in the summer if I don't go over 70 mph. I think I have a 185 stat and a plain old stock appearing radiator with a fmic and dual Spal fans. No moisture in my oil lol!!!
Flyin Brian
Member
- Joined
- Jun 18, 2011
I doubt it is the water pump but anything is possible. You can start it up with the radiator cap off and wait for the thermostat to open and watch the water flow.
Was this situation with the AC on? Do you have a front mount IC? Is the radiator boxing in place? Lock or non lock torque converter?
Flyin Brian
Member
- Joined
- Jun 18, 2011
Well that rules out a lot of possible issues. It really should be running cooler then, especially without a FMIC. You can try the things that John mentioned above.
I don't have any experience with the F-body radiator but everyone uses them. What are you running for coolant? Water and RMI-25 will cool better than water and coolant.
When you see the water flowing through the radiator tubes it should really be flowing good. I had a problem with a cheap radiator where the tubes were too narrow and the water would flow but not fast enough.
The car would eventually get too hot. The hot side of the radiator would be really hot but I could put my hand on the cold side.
Could be your tune is too lean at cruise? I am guessing here. A vacuum leak could do that I think.
Flow Kooler makes a really nice water pump for our cars but in my experience my overheating problems have never been due to the water pump on any vehicle.
I did a very thorough job on boxing in the radiator in my car because it ran hotter on the freeway. Air entering the grill was just hitting my FMIC and going straight down under the car instead of through it.
I bought the boxing kit and customized it some. Air entering my grill now is forced through the inter cooler and condenser and radiator. As soon as I get above 45 mph the water temp will start to drop.
Keep looking. 200 degrees is not the end of the world but your car should run cooler than that.
I don't have any experience with the F-body radiator but everyone uses them. What are you running for coolant? Water and RMI-25 will cool better than water and coolant.
When you see the water flowing through the radiator tubes it should really be flowing good. I had a problem with a cheap radiator where the tubes were too narrow and the water would flow but not fast enough.
The car would eventually get too hot. The hot side of the radiator would be really hot but I could put my hand on the cold side.
Could be your tune is too lean at cruise? I am guessing here. A vacuum leak could do that I think.
Flow Kooler makes a really nice water pump for our cars but in my experience my overheating problems have never been due to the water pump on any vehicle.
I did a very thorough job on boxing in the radiator in my car because it ran hotter on the freeway. Air entering the grill was just hitting my FMIC and going straight down under the car instead of through it.
I bought the boxing kit and customized it some. Air entering my grill now is forced through the inter cooler and condenser and radiator. As soon as I get above 45 mph the water temp will start to drop.
Keep looking. 200 degrees is not the end of the world but your car should run cooler than that.
TurboTnZ06
Go on red!
- Joined
- May 7, 2002
Probably lean and or too much timing under load on the highway.
I run a fbody rad, my second one, and the lower factory tar paper boxing is all gone, I just have side ones left, and big trans cooler in front of the condenser and a stock fan, no problem at temp on the highway. I run RMI-25 and distilled water and 160 thermostat.
I run a fbody rad, my second one, and the lower factory tar paper boxing is all gone, I just have side ones left, and big trans cooler in front of the condenser and a stock fan, no problem at temp on the highway. I run RMI-25 and distilled water and 160 thermostat.
RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
Check that the radiator fan is blowing in the correct direction. Into the engine compartment. It has been known to wire the fan(s) reversed.
RemoveBeforeFlight
RemoveBeforeFlight
1KWIKSIX
Well-Known Member
- Joined
- Sep 29, 2007
Justin, my personal recommendation would be to simply add a bottle of RMI-25 to your coolant. It's the quickest and easiest thing to do.
You will be surprised at the 5-10 degrees it should lower your operating temperatures.
This has been my experience. Been running this additive for years.
Just gotta order it in from the US. Nick Micale (Arizona GN), Mark Huffman (TR Custom Parts), are just some of the vendors that carry this stuff.
You will be surprised at the 5-10 degrees it should lower your operating temperatures.
This has been my experience. Been running this additive for years.
Just gotta order it in from the US. Nick Micale (Arizona GN), Mark Huffman (TR Custom Parts), are just some of the vendors that carry this stuff.
Fans run in the right direction , I've tried burping the system in the past with no help.. My next move is too look at my tune, I also have half a bottle of RMI 25 left at home but I think that would be just a mask. I've talked to quite a few guys running the Fbody with stock fans even and only hit 174 max.
At highway speed the Fan shouldn't even be in the equation .. sounds like there is blockage in the radiator
