2G Running Hot But not Quite Overheating yet...

[eddie1525]

I have been reading through a bunch of cooling issue threads here and haven't quite found one like mine. Car get up to temp. and fan comes on right about 190 and both upper and lower hoses get hot. then after a few min of driving at cruising speed 65-75mph on freeway or back roads doing 35mph the car runs at 200-210 pretty consistently. Once I down shift or step on it and get into boost the temp gauge rises quickly. I've never been able to really pull more than one gear cause this temp gauge scares me when it gets up there. I've seen it up to almost 220 a couple of times after a pull on freeway and temp gauge reads 220 but the stock water temp gauge in the dash shows normal temp.

Any ideas what I could do to keep the temps in the 190 range and still be able to rip on the car a little?

Set up:
4G63T 7 bolt stroker motor on 17 psi making about 330hp to the wheels.
Mishimoto Radiator, single Mishimoto rad fan. no AC but I do run a FMIC.

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[SixBolt_16G]

Just for clarification... were your temperatures previously fine and this just started or has it always been doing this with your current set up?

i recently had to solve similar issues with the temps, highway cruising and elevated temps after rips, with a much smaller EVOIII turbo, front mount and FP Manifold. Three things that helped me....

1. Front mount blocking the radiator inhibits cooling....Look into making an air dam that will direct air under the car to prevent air from bypassing the narrow gap and force it up to the radiator. There are a couple of threads that have examples of it. (Hope one of the 3d printing freelancers could offer an official one). Blocked off the gap at the top area between the radiator and mounting brace with some simple weather stripping to keep air from passing up the radiator.

2. How old is your radiator cap? I replaced mine an Evo 1.1 bar that ibe had sitting around for a few years.

3. Try to verify that your exhaust manifold to turbo gasket isnt going bad and breathing fire directly on the radiator. Also check that your external wastegate isnt doing the same.

 

[eddie1525]

Thanks for the tips. Temps have always been like this since the full rebuild of the car. Its been a few years putting it all together and then finally tuned it a few weeks ago.

1. I have been thinking about putting some 3” ducts on the fog light bezels and running them around the fmic so the radiator can get more fresh air.
2. Cap is as old as the build about 1300 miles on engine but as simple and cheap as they are I’ll swap it out too.
3. Turbo gaskets are good. That was one of the first things I checked. That area does get very hot so maybe a custom heat shield needs to get built…

If you got any other ideas Im all ears. And thanks again for the advice. Oh and if you know of the thread for that air damn Id love to read it?

 

[chrysler kid]

Is it the stock radiator and fans?

The mishimoto slim fans are notoriously under powered and the fan shroud lacks positive pressure slats ( to allow air flow through the fan shroud when the air pressure from the vehicle moving is greater than the suction power of the fans)

The aluminum radiators also add air flow restriction and double the amount of fluid trying to be cooled by the airflow. So you are effectively adding air flow restriction by making the core thicker, and then putting twice the amount of coolant with half the amount of air going through it

Here in texas I find regularly that I have to switch these modified cars back to a factory radiator and factory fan setup to keep the ac working and prevent them from overheating if the car has a front mount

For reference, remove the front bumper to see if duct work will have any positive effects. My primary hunch is that your fan shroud is restricting air flow through the radiator

A good shroud should have positive pressure slats

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[eddie1525]

Interesting… yes I have both the Mishimoto radiator and fan shroud kit. However I had to modify the shroud as it would not fit with my turbo and manifold set up. I was thinking about mounting another fan on the other side of the radiator and switching the polarity so the fan pushes air through but Im also the kind of guy who likes using the factory harness and connectors and if I do reverse the polarity I think Id have to run an aftermarket switch right?

 

[DSMPT]

I've seen it up to almost 220 a couple of times after a pull on freeway and temp gauge reads 220 but the stock water temp gauge in the dash shows normal temp.

To me, it doesn't sound bad. 220F is not really overheating and kinda normal on a 2g with a FMIC. My 2g acts similarly but mine even gets hotter than yours during summer as I live in oven.

but the stock water temp gauge in the dash shows normal temp.

This too. It doesn't sound abnormal to me, the stock coolant temp gauge would react slower and the gauge would still stay below half line especially if the 220F is just momentary.

Run two fans and if you have ECMLink or some sort of fan controller, turn on the fans early (combine with a low temp thermostat would be better). This would help a lot to keep the coolant temp range lower.