2G Highway slight overheat, in town temp gauge is fine

[idkiliketurbos]

Hey guys, my car on the highway will overheat a little bit when its hot out. In town the temp is fine. It has a punishment fmic kit with the front bumper trimmed. I can't come up with a solid culprit from my searches besides possibly some ducting. Any other ideas?

 

[007jimmy]

Is your coolant system up to par? Still have your ac condensor?

 

[MiroDSM]

Check fans, coolant, tstat. Do you also have ac? I was also slightly over heating, and I searched this site and I found the answers. You might need to add ducting since air coming threw escapes to the sides and very minimal makes it to the radiator.

 

[97Chitclipse]

Its your front mount and ac condenser not letting enough air through, id get rid of thd stock fans and get slims and a better radiator

 

[mattasi]

I would keep the stock fan if possible, it is better than the slim fans.

 

[slayer450]

Fans have nothing to do with it at highway speeds, they are mainly for traffic and idling conditions. It's probably not getting enough flow because of the fmic and the ac. You could have a pin hole in your system somewhere or your rad cap isn't holding pressure

 

[mattasi]

Fans have nothing to do with it at highway speeds, they are mainly for traffic and idling conditions. It's probably not getting enough flow because of the fmic and the ac. You could have a pin hole in your system somewhere or your rad cap isn't holding pressure

Correct the fan have absolutly nothing to do with the highway speeds, but the dude that posted above me was telling him to get slim fans, and that is not good advise.

 

[slayer450]

Correct the fan have absolutly nothing to do with the highway speeds, but the dude that posted above me was telling him to get slim fans, and that is not good advise.

Idk, I know eventually I'll be getting slim fans but not it'll mine die. I'm a firm believer in if it's not broke, don't fix it.

 

[Lofty]

Do you have an OEM waterpump? Ive heard of waterpumps doing weird things at freeway speeds if they arent OEM.

 

[idkiliketurbos]

Okay well sometime this week i'll have to try to make some ducting. I just got the car a few days ago, and on the highway at night/cooler temperatures, my needle didn't appear to move at all, but when it was 85+ out, it would raise up about 1/16th of the way, and then go back down to where it would fix to in town.

 

[slayer450]

So you're going by the stock gauge? Get a real gauge and see what it is actually doing.

 

[007jimmy]

Do you have your stock heat shields around the manifold and turbo? without them you can heatsoak everything under your engine bay specially at highway speeds. I melted my A/C fan and blew my alternator when I didnt have them

 

[92boostinawd]

Idk, I know eventually I'll be getting slim fans but not it'll mine die. I'm a firm believer in if it's not broke, don't fix it.

With these cars the motto is a little different " if it's not broken be prepared to fix it"

 

[miguelmcv]

I used to have the same problem when I put my Front FMIC,It used to overheat at high way, But it was always good on Street, All what I did was Air Duct and it fixed the problem.
Later on I put some 10" slim fans (pushers) between Condenser and Intercooler to clear some space and
it start to overheat again, so I put a 12" on the stock place and it fixed the cooling issue, then I did the 2gb swap (Front Bumper), and I removed the 12" fan, so I am all good now with just 2 10" slim fan in front.

 

[idkiliketurbos]

Yes, I still have the stock heat shields. I had the fan melt problem on my last dsm.

Last night I put a new thermostat in just to see if that had any effect. I added a little bit of coolant, started the car, turned the heat on, and then let it idle for about 20-30 minutes. I noticed air bubbles coming out every once and a while, so I kept it running. The factory temp gauge never got above halfway during the entire time. The heat was blowing hot the entire time, and I noticed my fan never turned on once during the idle time. I took it for a drive after that and the temp never moved, although the fastest I got up to was about 65. Tomorrow I'm going to take it out on the highway and use my scan tool to get the actual temperature numbers that it is running.

 

[marc97gst]

I am currently having the same issue. I was able to do some ducting (cut a big hole beside the mitsu logo), but still having issue it's just delayed for a few extra highway miles.

 

[Cesarlcase]

I'm pretty sure It's your radiator being dirty or clogged. I don't have any ducting on my car with a big fmic and have no overheating problems even after a hard run after (temps go up slightly). I did have that kinda problem before, changed the rad and all was good ever since with distilled water for the summer. Good luck

 

[idkiliketurbos]

If the problem persists I'll clean out my radiator. The Fins on the front look to be pretty straight for the most part as well as with the ac condenser. I'll do a little more research on ducting and attempt that next week at some point.