Temperature Question

[59caddyhog]

Hi, Couple of questions moved from another thread

1. My truck runs 200 or even a shade over in traffic.
2. Is that OK coz it's only about 10c-12c here at the moment?

Thanks to one of the guys I have ordered a 170 thermostat from JMB but I would still like clarity on the top 2 Q's.

My truck doesn't have a flashed PCM, It doesn't use any water and seems fine but you do see a heat haze coming out of the hood scoop.

The temp does drop below 200 when it's on the move.

Could I ask you guys to use plain speak coz I don't understand all this hi-tech Jargon. I'm 42 and English.

The last time I "flashed my PCM" got me 6 months in jail.

Thanks up front guys, Andrew.

 

[GADodgetech]

Change the t-stat and you'll be A-ok.:top: :top: Make sure the fan is working too

 

[Brat]

Hi, Couple of questions moved from another thread

1. My truck runs 200 or even a shade over in traffic.
2. Is that OK coz it's only about 10c-12c here at the moment?

Thanks to one of the guys I have ordered a 170 thermostat from JMB but I would still like clarity on the top 2 Q's.

My truck doesn't have a flashed PCM, It doesn't use any water and seems fine but you do see a heat haze coming out of the hood scoop.

The temp does drop below 200 when it's on the move.

Could I ask you guys to use plain speak coz I don't understand all this hi-tech Jargon. I'm 42 and English.

The last time I "flashed my PCM" got me 6 months in jail.

Thanks up front guys, Andrew.

Yeah the 170 thermostat should help,but you really need to get the pcm flashed,that way the fan will come on sooner and help the thermostat work to it full.I have a extra pcm send me your address and I will send it to you so your truck wont be down for the weeks it will take to get it back.:rock:

 

[Prof]

In addition to the comments above...many vehicles run at 210 to 220 and are designed to do so. We get a little concerned with temps over 200 here, but I think we are a little hyper sensitive. I doubt that you will be driving much in very high temps...so rest easy.

 

[59caddyhog]

Thanks to Brat for the offer.(I sent a PM)

.......and Cheers to Prof, that is the answer I was hoping to hear. Everythings good

In the UK, on the best day of the year, it might reach 80-85f.

I'll chill now.:rock:

 

[Da1Chief]

Andrew,

Remember these engines are aluminum and as such are designed to perform best at around the 200 to 210 temp range. Aluminum engines that run too cool do not develop the max power and efficiency they were designed for. Basically Too Cool you loose HP / Too Hot you loose HP. There are many individuals here that could go into the technical aspects of this (way smarter than I am on these matters).

(This statement may start a war) In my opinion normal in town traffic and normal driving will not let the engine get to max power if you go with the 170 TStat. The 170 will give benefits if you live in a hot climate (above 100) which will then let the engine cool to down to "Normal" temps.

 

[Chuck B]

We average over 90 days a year well over 100F. Mine pretty much lives at 200-205 temp range. On the hottest days if I'm running it aggressive temps will creep up. At about 210F (our gauges are not exactly accurate btw) the ECU will pull back on your timing to help reduce heat. Its significant enough that under WOT you'd think you had lifted the gas pedal when this occurs. Feels like instant 100hp just disappeared. Mine is still stock with lots of miles running around in our hot deserts with no issues.

If you want a fix, my opinion is to have the ECU reflashed to turn the fan on sooner and with quicker speeds. Personally, I don't think going to lower thermostat is the right way. Besides the fact aluminum engines perform better with a little heat in them, if I simply installed a 170 thermostat I'd still be averaging 200-205 temps. Around 185 the factory thermostate is wide open flowing as much water as possible. Going with a 170 just means your flowing max at lower temp. If temps get over 185 your in the same boat as before. What you need is to either increase the radiator size or have the fans begin to kick on at say 185 versus 205 plus that the factory has them come on to aid in cooling.

 

[Prof]

If interested there is one other modification that costs less than a dollar but helps with the heat soak issue...when temps rise and the pcm senses higher IAT temperatures...timing is pulled to assure that the engine does not experience detonation due to the leaning of the air/fuel mixture.

Many of us have installed a 5.6 ohm resister in the IAT wiring. This additional resistance in the circuit fools the pcm into reading a temperature that is 40 or 50 degrees less than the true setting...that reading by the pcm inhibits the pcm from pulling timing to protect the engine from detonation.

A search here will reveal the instructions for doing the modification...literally less than a dollar and five-ten minutes.

http://www.vtcoa.com/forums/showthread.php?t=24177

 

[59caddyhog]

Maybe I should have done this earlier but 200f is only 93c.

When you look at it like that, it's no where near boiling point and water doesn't boil until considerably higher in a pressurized system anyway.

 

[EMT/SRT]

In Florida it's HOT near about all year! My QC runs 200-205 all the time. No problem.

 

[v10 fat]

Maybe I should have done this earlier but 200f is only 93c.

When you look at it like that, it's no where near boiling point and water doesn't boil until considerably higher in a pressurized system anyway.

my truck is the same fella.

 

[SRT-IZ]

Question: I have a flashed pcm and a 170 thermostat, it still runs at 200 all day. Any idea why? Im just a little concerned that the summer heat (<100 dag) will raise the trucks temp and damage something.