996 Carrera running hot!

[noahsdad]

Hello all. Looking for some advice on how to cool things down on my 99 Carrera. The engine was recently rebuilt and all is running well. However, when driven hard on warm days (uphill climb Angeles Crust) my temp rises just past 210 and oil pressure drops more than I like. My radiators are clear of debris and my cooling system was refreshed with the rebuild. I am interested in adding a 3rd radiator, which seems to be the only option available. Is there an auxiliary oil cooler I can get? Thanks in advance.

[32wildbilly]

Hello all. Looking for some advice on how to cool things down on my 99 Carrera. The engine was recently rebuilt and all is running well. However, when driven hard on warm days (uphill climb Angeles Crust) my temp rises just past 210 and oil pressure drops more than I like. My radiators are clear of debris and my cooling system was refreshed with the rebuild. I am interested in adding a 3rd radiator, which seems to be the only option available. Is there an auxiliary oil cooler I can get? Thanks in advance.

Are your cooling fans working? Both sides and on low and high speed?

What was the ambient temperature during your romp?

[noahsdad]

Fans were checked and working properly. Temp was 80-85. Would fans come into play while car is at speed? BTW, the car cools down nicely when I back off.

[32wildbilly]

Fans were checked and working properly. Temp was 80-85. Would fans come into play while car is at speed? BTW, the car cools down nicely when I back off.

Yes fans would come into play at speed if the engine heats up to the point of triggering the sensors that control the fans. More speed means more fuel burnt and more heat produced. Speed air flow helps but apparently not enough. Do you know how the shop tested the fans? I have never pushed my car super hard but it sits at the left side of the 0 in 180f even in temps approaching 100f ambient but then again I've read that gauge is not super accurate. Another question: how hard are you pushing it? What you are seeing might not be that unusual. I just don't have experience with this issue.

[gnat]

30 minute track sessions on a god awful hot day (100+ in the shade with no breeze) didn't raise my temps to anything to be concerned about. Neither does banging around at 60-80 in 3rd on similarly hot days. The only time I've seen my temps creep up is on 100+ days stuck in traffic where it is doing more idling than moving.

My understanding is that the only time the 3rd radiator is required is if you are doing serious track time. It certainly wouldn't hurt things in an otherwise functioning system, but I'm not sure it's your answer here.

Check the thermostat to see if it is functioning correctly. The temp sensor is on the "wrong" side of the thermostat so when it is closed it is telling you more about the radiators than the motor. If your thermostat is malfunctioning (or the wrong one) and not opening at a low enough temp that could fit what you are seeing.

[noahsdad]

I will find out and double check about the fans from Indy. I push the car fairly hard. Its a 7k climb over about 40 miles. I'm between 3000 and 5000 rpm most of the way with no stopping. This romp is not an average use of the car, so maybe that's just the way it operates under these conditions without a 3rd radiator. BTW I agree with you that the gauges are not that accurate.

[noahsdad]

Yep, I will double check the stat. Thank you. BTW, airflow should not be a problem as I'm in 3rd and 4th almost the entire 40 mi. I have tracked other cars and I would say this is a similar scenario to track time.

[gnat]

BTW, airflow should not be a problem as I'm in 3rd and 4th almost the entire 40 mi. I have tracked other cars and I would say this is a similar scenario to track time.

Given this plus the altitude change, this may simply be how things are and the 3rd rad might actually be of benefit here.

Being an East coaster I had to look it up, but you are looking at a roughly 20-25% drop in air pressure from bottom to top. That will have adverse effects on the motor that is likely going to impact the heat it generates. I don't know enough about performance driving at altitude to know how much of a factor that is going to be though.

[noahsdad]

Agreed. Thinner, high altitude air cannot cool as well. Indeed that may be the issue here. Thanks everyone for your input. I will double check the stat and fans though. Easy and cheap enough to rule those out.

[OceanBlue2000]

Is 210 F that bad? I recorded a trip the other day on my new ODBII reader and 210 was the highest read in the coolant temp. The needle was I think over the zero where it usually is.
All my “forum research” shows that a lot of guys cars are this hot.