94 z28 running warmer than I would like

[cjlopez956]

So I have my 94 z28. It tends to run hotter than I like it too sometimes almost getting up to 195 with a/c off. Tends to get hotter while holding speed and cool down when stopped. Just installed new radiator, water pump, 160° thermostat and did a flush beforehand. The problem was present before I changed all the parts, radiator did have a leak though. Please tell me what you guys think. Car has cam, Bolt on's and a built trans.

[blackbirdws6]

I assume you have a tune to kick the fans on earlier? First impression is you do not have all of the air out of the system. Nothing blocking the air damn below the car right?

[cjlopez956]

Yes I think tune is set to 180 for one fan 185 for the second. 180 for both if a/c on. Air dam is in place nothing blocking. It's possible I have air. My coolant overflow does have a leak, will an empty reservoir affect it? Car still does the same thing right after topping it off and bleeding system. It's run under 185 the past two years since I've gotten the trans built up until these past few months.

[bustedassz28]

I just replaced the same parts as you and my car won't even think about going over 180, I don't have ac tho, 195 really isn't that hot, I don't think. Maybe try water wetter, a manual fan switch, and check your a/c condenser for obstructions ( I would pressure wash it ) after you're sure all the air is bled. Just my opinion hope it helps...

[Dan]

The reservoir is for overflow. The radiator will suck fluid out of that to get more to help cool the car and dump any more so it doesnt come out of the cap.That is probably your problem.

Replace/refill the overflow reservoir.

[cjlopez956]

Just put a good reservoir tank on, rebled the system via the bleeder screws. Car is still exhibiting same problems. Runs hotter while accelerating and holding higher speeds. Immediately starts cooling down the closer I come to a stop. That's with a/c on and 80° outside. It did run cooler with a/c off.

[tleed]

Probably time for a new radiator or water pump

[cjlopez956]

New high flow water pump, OEM radiator, both new temps sensors, and new thermostat have been installed. Just like I said in my original post. Problem was present before, new parts only helped a little bit.

[tleed]

There could be a blockage in your crossover tube that runs to your heads

[cjlopez956]

I tried loosening the bolt holding down the tube and the stripped. So before I remove the cylinder heads, do you think an additional flush might do the trick?

[popo8]

What weather are u having when u are seeing this "hot" running condition?

LTXtech.com IS my drug...

[popo8]

Do u still have the air-dam under the cat?

LTXtech.com IS my drug...

[popo8]

Never mind... just saw air damn is still there

LTXtech.com IS my drug...

[popo8]

Ur car will want to run hotter with the ac on... thats why the factory makes the second fan come on when running the ac... because the first fan is not sufficient.

LTXtech.com IS my drug...

[cjlopez956]

The weather doesn't seem to matter. I've had the car start warming up passed 185 and slowly keeps escalating (I don't let it go passed 210) at expressway speeds with 80° weather outside at night. I can understand a hot running car during the day when its 105°. It tends to cool down once I come down to idle. Both fans are on at 185°. First one on at 175°. All of this with the a/c off.

[SJx408]

This is strange typically cars with cooling issues run warmer at idle due to decreased airflow, once you hit highway speeds though temps should drop. Here's the exact opposite where car runs cooler at idle because of reduced load I suppose. I would assume air dam on fans lower new water pump and all of the other upgraded parts should have resolved the issue. I'm typically running at around 190-210 depending on weather stock thermostat stock fans but an EWP and a 3 row all aluminum "race radiator". Figured these cars were designed to run warmer than most so it's okay. When I first got the car it had a 160 degree thermostat and it never got above 180 but then it failed and in a pinch I just bought a stock one. Interesting issue you got here.


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[kris72079]

As much as it doesn't seem likely to be the issue, especially with new parts, it's screaming water pump. Either cavitation or bypassing at higher rpm. Did this issue arrise after the wp upgrade? I see it daily, new parts can be bad.

[kris72079]

If not that, I'd second steam pipe.

[matt94z]

Make sure the splines on the water pump drive aren't stripped.

[cjlopez956]

It had the same problem on the old water pump, but I could feel the bearing on the pump a little loose already. Splines are fine, This new pump just helped it run I a little bit cooler.

[cjlopez956]

It had the same problem on the old water pump, but I could feel the bearing on the pump a little loose already. This new pump just helped it run I a little bit cooler.