Mishimoto Radiator

jsumner83 · February 15

I have a 2017 gmc sierra 1500 5.3 4x4 that I use to tow my travel trailer here in Arizona. While towing on grades, I notice the engine temp will keep up to 240 degrees, but then go back down once the truck levels out. I have been reading a lot about different mods, changing the thermostat, etc. but what I really want to do is as the Mishimoto radiator. There isn’t a lot of info out there in terms of anyone doing it and what results they had. I did read somewhere that some guy purchased an all aluminum 3 core radiator (not Mishimoto) and it worked so well that he had all kinds of warning lights in his Silverado cause the motor never got up to temp. My question is, will I need to also change the thermostat and have the fan settings changed after I purchase this radiator, or do we think stock settings will Be fine. Let me know. Thanks!

rav3 · February 15

I cannot give you any info on the Mish radiator. However, your coolant temperature is regulated by the thermostat. If I were you (and you're not) I would buy a EL327 OBDII Bluetooth dongle & download an OBDII App to my phone & read the actual coolant temperature versus what the dash gauge says it is. on my 2017 5.3l with Max tow package, shows just a hair under 210F on the dash gauge, however, when i read it from via the OBDII app, it is actually 175 to 190F, which is cooler that I originally thought. Also, running a cooler thermostat is a cheap & easy 1st mod to try over the cost of a $1000 radiator.

Good luck & try the simple things first.

Grumpy Bear · February 15

I agree to a point. The thermostat sets the temperature. UNTILL the capacity of the radiator is overtaken. When the thermostat is wide open the temperature is still on the rise well over the set point (health motor naturally) then there is not enough reserve, and a larger radiator is the cure as a colder thermostat will not help.

No special setting or tune is required for this modification.

CajunFries · February 16

I’m running a Mishimoto radiator and Katech Tstat. I love it. No more overheating in 110+ day + towing up the hills. It is a lil bit thicker than the factory one just a heads up.

Grumpy Bear · February 16

12 hours ago, CajunFries said:

I’m running a Mishimoto radiator and Katech Tstat. I love it. No more overheating in 110+ day + towing up the hills. It is a lil bit thicker than the factory one just a heads up.

Is it plug and play? Or do mounts need modification and so on?

CajunFries · February 17

11 hours ago, Grumpy Bear said:

Is it plug and play? Or do mounts need modification and so on?

All plug and play.

jsumner83 · February 21

Just ordered mine. Do I need to order the chill coolant or can I use an over the counter brand?

CajunFries · February 21

6 hours ago, jsumner83 said:

Just ordered mine. Do I need to order the chill coolant or can I use an over the counter brand?

Regular coolant is fine. I would suggest replacing the thermostat while you’re there. Either another factory AcDelco one or one from Katech. Nothing else. If you do get one from Katech, get the warmer opening one or else it might throw a CEL.

jsumner83 · February 21

I have a 180 degree thermostat that I ordered from summit that I planned on throwing in. I’ll look at the katech ones now.

CajunFries · February 22

12 hours ago, jsumner83 said:

I have a 180 degree thermostat that I ordered from summit that I planned on throwing in. I’ll look at the katech ones now.

Looks like the highest one they have is a 174. I’m not sure what the threshold is for the ecu to not throw a CEL. My 160 keeps my coolant temp right at 160-165 even on a hot day as long as the truck is somewhat moving. That would definitely throw a CEL if it wasn’t tune for it.

Homewrecker007 · February 22

I believe the 174° will throw some codes. I put the corvette 195° in mine not a huge drop. But it doesn't throw codes.

Grumpy Bear · February 22

1 hour ago, Homewrecker007 said:

I believe the 174° will throw some codes. I put the corvette 195° in mine not a huge drop. But it doesn't throw codes.

Nope. I run a Reische Racing 170 F and zero codes over several years. The 160 F stat will toss a code and requires a tune.

Edited February 22 by Grumpy Bear

jsumner83 · February 22

I will try the 180 and see what happens. I planned on getting a tune at some point so I could have it corrected if a code shows

Homewrecker007 · February 22

8 hours ago, Grumpy Bear said:

Nope. I run a Reische Racing 170 F and zero codes over several years. The 160 F stat will toss a code and requires a tune.

I stand corrected.