Last night I went for a drive on the interstate, and my engine temp was hovering right around 167 degrees...... the external temp was around 32.

I just installed a Stewart Stage 1 water pump, and an 180 degree thermostat about a month ago. Also, I cleaned out the dead air zone in front of the radiator, put in some new Prestone and some water wetter.... I have not reprogrammed my fan to kick on sooner so it still kicks in at 227 degrees.... And I was running ECON on the temp control unit so the fan should not have kicked in because of the compressor running.....

Can someone explain why the temp did not get to 180, and stayed around 167..... From my understanding the thermostat should still be closed at this point.....

One more thing, I went to a drive thru before going on the cruise and the engine temp got up to 198 while sitting in line....

By the way, the car is an 86 with the L98 motor..... I think that covers it all.... Any thoughts??????

 

if the outside temp is that low, it prolly wont get there

 

Same problem here with the 84 running a 160 stat. Temp runs between 190 and 200 in the summer. However in the winter 30 degrees or less it never gets over 165 running down the road. However it will reach 190 if it sits and idles for 30 minutes, but put it on the road and back to 165. I guess it's just the nature of the beast. It won't run in closed loop until it hits 175 degrees at least. 84 CF 91 ZR-1

 

You are at least running over the thermostat setting..... I'm running a 180 degree stat and only getting 167 degrees out on the open road.....

 

It's just dumb speculation, but is your temp sensor sending you the correct number? How old is the sensor?

 

Its either your temperature reading on the engine is off or the thermostat is letting coolant by. Could be a lower temp thermostat than the box said it was but that would be a long shot. Your engine temp should get up to at least 5 degrees over the thermostat temp....

 

did you verify that you properly purged all the air bubble out of the neck and internal block? I know when I replaced my 180 and refilled got all the bubbles out that day..........two days later the overflow was bone dry........coolant sliping by due to air??? Might want to check it again and repurge the (not drain) system

 

Did the 167 degree measurement come from the analog gauge, the digital readout from the ECM/through a scanner, or from the readout on the C68 electronic readout (not sure if that feature is available for the car).

Typically, analog and digital readouts are within few degrees, assuming accurate gauges/sending units.

When the thermostat has not reached the design open temp, the water is simply circulating around the engine. Your radiator is obviously not involved, yet. If it is cold enough, and this is usually quite cold, the stat may never open. This is why some vehicles require the winter radiator/grill cover, engine receives too much cold air.

Now, assuming you have a 180 thermostat, cooler day, when the engine hits 180, it opens, and water will be redirected through the radiator. If you have a cooler day, and your radiator is very clean, cooling system very efficient, good coolant flow rates, traveling at modest speed with high air flow through the radiator, the thermostat could cycle many times, open and closed, keeping the temp very close to around 180, maybe a few degrees higher depending where you measure.

On the SAME day, sitting in line, the thermostat will definitely open, water flows through the radiator, however with far less air flow, the water to air heat exchange (radiator) is not that efficient, (keep fan ON temps in mind, this obviously helps flow). Remember, a thermostat is the point at which coolant will have access to the radiator. That's it. Once the thermostat is open, it really doesn't care how HOT your car gets. ONLY job is to close below X point and open above X point. ONE data point. So, once the water starts flowing through the radiator, we begin to find out how EFFICIENT the cooling system REALLY is. At some point, the system may need help, temps are rising, (thermostat doesn't care) the fan(s) are turned on, depends on how many you have, the temps, A/C on, etc. At some point, the car assumes you have enough speed/airlow (usually around 35-50 mph depending on design) and will remove electrical power from the fans, assuming safe temps(check the design specs of your system).

You have cleaned the radiator, good pump, and doesn't really seem to be misbehaving. Good procedures. I would want to verify the numbers cause you seem to have a system responding to good maintenance, seems like the values are just a little off. I too would have expected numbers around 180 or so, at least while moving.

Hope this wasn't too boring. Go Huskers.

dlmeyers 90 coupe zf6 3 speed shocks

 

[QUOTE]Last night I went for a drive on the interstate, and my engine temp was hovering right around 167 degrees...... the external temp was around 32.[snip]

:cheers: Sounds about right!

Thermo, regardless of temp rating, doesn't open until the water temp reaches the thermo setting.

These things (C4's) run a wide range of temps, depending on outside temp and whether you are moving or not.

I was out today, in 52 degree outside air and my water temp was 172, oil was 184.

As long as you are moving along, the air crculation under the hood seems to keep things cool! When you stop or get stuck in traffic for long periods, all H^&l breaks loose and you get water temp readings in the 220+ area

 

:cheers: PS

I have a 180 thermo. When I start and let idle, without moving, temps run up pretty quickly to 184-185.

Then thermo opens and temps drop down to 173. If I continue to stand in place at idle, temps will head on up to over 200+

If i start moving temps will stay in 170 range till I am stuck at lights or in traffic. Then they will move to 200+

I think your sensor is fine

Jack

 

The Stewart pump has much higher pressure which is forcing coolant past the 180 stat (it may be forcing it open slightly) and this is why your engine temp is 167 on the road (high rpm). I also put a Stewart pump on my 87 this Spring and have a 195 stat. In the summer my coolant stayed around 195, but now it is around 190 on the road and I also cleaned out my radiator. If your 180 stat has some small bypass holes in the vane, that contributes to coolant flow and your radiator with the cold outside air through it has much higher ability to transfer heat.

 

I have the same situation as you. I'm not sure where the water temp sensor is, if it's not near the stat, this could be one reason for the difference. I was running exactly 167 degrees on the highway in ~60 degree weather earlier today. It's possible that the Stewart is forcing the thermostat open. Or, if you have a drilled stat, water temp can also stabilize based on this flow before the stat opens. I heard somewhere that the reason for the spring on the thermostat is to allow the waterpump to flow past it to some degree, to relieve pressure in the system. The stewart obviously generates more pressure than stock.

With air temp at 30 degrees, my car wanted to run at only 130 degrees with the vent set to hot. I had to run the A/C just to keep the water temps up. This was after 45 minutes of highway driving, so the car was as warmed up as it was gonna get.