Engine running temperature


gtforme

GT Owner
Apr 12, 2009
348
I was out driving today and the car started running up around 200 on the temp guage so i put the AC on and the temp went down when I was dirving but went back up to 200 when sitting in traffic , is this normal and when do I need to be concerned about the engine temp , 220 ??
 

t32b

Verde
Mark II Lifetime
Jul 21, 2007
432
Bay Area, CA
Correct me if I'm wrong, but putting the AC on when the car is hot is not the right course to correct the problem. It likely will make the problem worse, particularly, as you noted, at standstill. The age old salve for a quick dissipation of heat in a street car is to put the heat full on and blower full on. Shut off all other accessories and keep it moving with no lugging.
I've not seen temp that high unless it was it was in stop and go traffic on a very hot day. And a quick run on the highway before heading home on the back roads is all it takes to cool her down.
Rich
 

Kayvan

GT Owner
Jul 13, 2006
4,782
A/c puts on high speed fans, so right move

200 is fine 220-240 is red zone

Get in open space, over 70 and it will drop to 180 fast
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,219
North Carolina
AC running does lower the temp as stated in other postings. Wheter I need it or not the AC is always on in my car.

You can also get the SCT programmer and turn then on "earlier" via the ODBII port.

Torrie can help with this.......
 

2112

Blue/white 06'
Mark II Lifetime
Just to add, I thought that when in a bind or emergency and you are running way hot. Running the A/C but with the temp at max heat was a way to dissipate excess heat, though it may be uncomfortable. kind a variation on T32b's version.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,301
Just to add, I thought that when in a bind or emergency and you are running way hot. Running the A/C but with the temp at max heat was a way to dissipate excess heat, though it may be uncomfortable.

Back in the day (BITD), one of the best things you could do for an overheating car is to turn the HEATER on max. The heater core within the car is essentially just a radiator inside the car and it too could dissipate heat (to the discomfort of the occupants !) Normally, you would never want to turn on the AC in an overheating car because this turns on the AC compressor and increases the load on the engine.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Back in the day (BITD), one of the best things you could do for an overheating car is to turn the HEATER on max. The heater core within the car is essentially just a radiator inside the car and it too could dissipate heat (to the discomfort of the occupants !) Normally, you would never want to turn on the AC in an overheating car because this turns on the AC compressor and increases the load on the engine.

:agree:

If your engine isn't overheating <228F and you for some reason what to lower your coolant temps with a stock tune, then turning your A/C on will force the high speed radiator fan on which helps lower the coolant temps. The coolant thermostat opens around 172-180F, but the fans don't come on until at least 210F (low speed) and the high speed at 228F. With a custom tune you can change when the fans come on to whatever you like. Torrie can help you if you what a different fan temperature.
 
H

HHGT

Guest
Back in the day (BITD), one of the best things you could do for an overheating car is to turn the HEATER on max. The heater core within the car is essentially just a radiator inside the car and it too could dissipate heat (to the discomfort of the occupants !) Normally, you would never want to turn on the AC in an overheating car because this turns on the AC compressor and increases the load on the engine.

This is one of the first mods Kendall did for me.
 

Neilda

GT Owner
Oct 19, 2005
3,559
London, UK
The age old salve for a quick dissipation of heat in a street car is to put the heat full on and blower full on.

When I was running mine at Le Mans last year, the engine temperature became very hot - and this (above) is just what I did. It lowered the temperature whilst I was at race speed. It made for a very uncomfortable cabin, but it's a sure fire way of taking heat from the engine bay quickly.
 

JAYGT

GT Owner
Nov 20, 2010
175
MIAMI
I can attest to the difference with a custom tune on a GT mine does not pass 180 even stuck in Miami Beach 90F heat with bumper to bumper traffic with absolutely no airflow in the front of the vehicle. I had the same experience in my viper after a custom tune and a lower thermostat were installed although I also had to get rid of the (4) cats and bulky mufflers, that viper went from an easy bake oven to an enjoyable car overnight. Needless to say I am a big fan of custom tuning and adjusting fans to come on sooner.