Hello! I have an '04 Coupe 6MT, and I'm at Mid-America Motorplex this weekend with NASA. I'm having an overheating issue today and am hoping for some ideas. The engine is mostly stock, it's around 85 degrees today, I've added a fairly large oil cooler and am running 30% coolant/70% H2O, along with waterwetter. When I push the car hard, the water and oil temps creep up until I have to back off and let it cool (which it quickly does but is very frustrating). Any ideas what I could do to keep the engine a little cooler? Thanks in advance!!!



-6MT4me

 

try a different t-stat? When I raced RX-7's I would drill a small hole to the stock one. Hope this helps.

 

Weird.. you aren't even running a turbo? I've run my 2003 350Z in 95-to-100-degree temperatures in Texas and it didn't overheat. Although last time (in May) I finally saw the temp guage go up a tiny bit, to maybe 5/8 -- still out of the red zone, but usually it's more like 3/8. So I installed a stillen oil cooler, and I'll give it a good test at the end of July.

Do you have anything obstructing your airflow at all? Anything non-stock on the front of your car? A bra, a "custom" grille, bodykit, anything? One guy was having overheating problems, and it was because his blingy grille was blocking over 50% of the airflow onto the radiator!

 

Make sure your cooling fans are working properly. Continuously cycling on and off to cool the engine, even if one is not coming on that will seriously reduce cooling. Good luck.

 

You have a bubble in your cooling system. Trust me. Take it to a dealer, they have a special tool to remove air.

 

Thanks much for all the responses!

1) It isn't the thermostat sticking and there isn’t a bubble in the system-- already tried those things @ the dealership.

2) I have a very large oil cooler installed that I'm guessing is diminishing the amount of cool air going over the radiator. I had it around 2" in front of the A/C radiator, and an experienced racer recommended I moved it back to 1/4" in front to reduce turbulence in between the radiators. That helped a lot, especially the oil temps. Went from 280F max on track to 240F. Didn't do much to help the water temp, though, as I'm probably moving greater volumes of warmer air off the oil cooler into the main radiator.

3) I took the fans out, separated the main radiator from the A/C radiator, and cleaned out a surprising amount of "grunge" from the fronts of both radiators. For a car w/ 34K and no winters, I was surprised at how much dirt had accumulated on the radiators. That definitely helped. Simple Green and a garden hose work wonders…

4) Very good question on grills, etc... I have nothing extra other than the OEM "aero lip" for '04 models. On this advice, though, I removed the OEM grill and left the space between the bumper and the hood completely open. That did help-- not perfect, but definitely better.

5) Has anyone ever calibrated the OEM water temp gauge to actual degrees F? I'm still getting within 3 or 4 small "ticks" of the topmost thick "tick" on the temp gauge, but I don't know hot that really is. I didn't have to back off this past weekend at Autobahn (South course), but the water temp is still rising halfway between where it normally sits and the H indicator. Very disconcerting. The oil temp never got above 240 F, though.

Again, thanks for the advice! Any further thoughts would be much appreciated.

--6MT4me

 

Interesting. So at the track, your temp gauge is towards the top tick, but your oil temp is only 240F...that doesnt sound right? You brought up a good point, in that you might want to check your cooling system temp with a seperate gauge. We had a case with one car, where the coolant temp gauge wouldnt budge, even as the coolant temps approached 230F. ECU was seeing only 185F, but actual coolant temps were 230F. Maybe you are seeing the opposite phenomenom. You can also check the resistance on your coolant temp sensor, to determine if you simply have a bad sensor.

Best of luck.

 

Get an aftermarket coolant temp gauge to make sure you are not overheating. Stock gauges suck, well on 240's they are only a 3 stage gauge. Cold, Operating, and You're ****ed

LanceKA-T

 

Both good suggestions-- an aftermarket water temp gauge would definitely clear up the mystery. I think the oil temp was so low because of my oil cooler. The OEM gauge does seem to be displaying somewhat useful information, but it's impossible to say without a "real" gauge backing it up...