New 2017 sierra 6.2!!!

[Grumpy Bear]

Taking my readings directly from the ECM with a Scan Gauge and comparing to the dash gauge.

 

Dash ECM

160 - 100

172 - 125

185 - 150

198 - 168

210 - 215

223 - 225

 

The zero is way off on the dash gauge but span to 225 is pretty close. No idea past that as mine never gets that warm. I have a 170 F thermostat. These readings were taken when I still had the 207 F factory unit installed. Basic, the dash gauge tells you when your warmed up. 

 

So back the rapid rise thing. You have a 207 F thermostat (+/- 3 F) but your loaded hard enough to not only keep it open but generating enough 'load' the hold the thermostat open and the temperature at 215 F meaning the radiator in now 'leading' the show. Any input or reduction in motor load will be pretty quick to show in sensible heat as a temperature rise. The cooling system rejects roughly 30% of the BTU"s of the fuel burnt. Above about 55 mph additional air adds no more cooling so any load fluctuation from the motor is noticeable on the gauge. 

 

 

 

[Grumpy Bear]

14 minutes ago, truckguy82 said:

Calling bullshit on that, 1000's of hours straight with no stopping....lets see the evidence

I don't have any first hand knowledge about the absolute number of hours the test goes on but I can validate that GM beats them to death. When rods were being developed for the original SMC they were tested at 110% of designed load for 1 million cycles or what the industry called 'infinite life' and kept blowing stuff up until the had parts that would hold the grade. Petersons publications "HOW to HOT ROD Small block Chevys" if you need a source of documentation to verify this lofty claim. Oh and can find a copy. 

[mookdoc6]

19 minutes ago, truckguy82 said:

You made the claim, I called BS, it's your turn to prove it. Got any evidence of this?

 

I'll eat my words if it's true, but come on, 1000's of hours at WOT?..... yeah f-ing right

 

GM did say somewhere it was ran for 1000 hours.......but this is GM saying 100's of hours....anyway the AFM was 400K cycles if you want to know that for testing.

The toughest test session on the Corvette’s LT1 Gen 5 engine was a grueling, GM-proprietary performance durability procedure, where it was subjected to a high-speed/high-load torture session that simulated full-throttle blasts from the equivalent of 0 to 120 mph. With simulated transmission shift points inserted during the high-load test, the engine cycles non-stop between peak torque and peak horsepower for hundreds of hours – the equivalent of thousands of miles.

 

As you can see 10 minutes means nothing!

 

 

 

[Crobinson16]

11 minutes ago, Grumpy Bear said:

Taking my readings directly from the ECM with a Scan Gauge and comparing to the dash gauge.

 

Dash ECM

160 - 100

172 - 125

185 - 150

198 - 168

210 - 215

223 - 225

 

The zero is way off on the dash gauge but span to 225 is pretty close. No idea past that as mine never gets that warm. I have a 170 F thermostat. These readings were taken when I still had the 207 F factory unit installed. Basic, the dash gauge tells you when your warmed up. 

 

So back the rapid rise thing. You have a 207 F thermostat (+/- 3 F) but your loaded hard enough to not only keep it open but generating enough 'load' the hold the thermostat open and the temperature at 215 F meaning the radiator in now 'leading' the show. Any input or reduction in motor load will be pretty quick to show in sensible heat as a temperature rise. The cooling system rejects roughly 30% of the BTU"s of the fuel burnt. Above about 55 mph additional air adds no more cooling so any load fluctuation from the motor is noticeable on the gauge. 

 

 

 

Was this a 6.2, and does your temp rise like i have described? The higest temp I got was 229, I feel sure it went higher yesterday when I went over the mt. It's not a big mountain it's only a 1400 ft clim and the dash displayed higher then what I had today.

[mookdoc6]

These engines are "DI" Like it Hot and quick!  made that way....

[Crobinson16]

1 hour ago, Grumpy Bear said:

Did you get a decrease in normal operating temp when you installed the lower temp thermostat? Heck it's only 30 degrees out and I'm getting higher temps

[Crobinson16]

39 minutes ago, mookdoc6 said:

These engines are "DI" Like it Hot and quick!  made that way....

I dont think so. 

The other 6.2 truck didn't do it, and I checked 2 other trucks today with the scanner though they were 5.3 trucks 2015 and 2017 , with normal operating temp of 195 and highest I could get either of them to rise was 212, and neither would do it quickly, I had to repeatedly accelerate them many times for them to get above 210. 

[amxguy1970]

On 12/8/2017 at 12:25 PM, truckguy82 said:

You made the claim, I called BS, it's your turn to prove it. Got any evidence of this?

 

I'll eat my words if it's true, but come on, 1000's of hours at WOT?..... yeah f-ing right

From the 4200 inline 6 testing " GM built 800 engines for development and testing. 24 engines went on the dyno and all met their 150,000 mile durability target. 5 of these were run WOT for 300,000 miles (let's conservatively say 5000 hours each) and all passed. GM put 4 million test miles on other vehicles validating this engine design alone." GM V8's go through a similar if not more grueling testing proceedure, they have to get them right as these engines are their bread and butter and what they are known for. Even in the years of questionable quality for GM vehicles the engines were aways the bright spot and notorious for reliability and power.

 

Many times cyclings is even more grueling, WOT for a set period then cool it off in a short period of time (or let it sit and heat soak) then back to WOT when cool can be even worse. Ford I read would do WOT for a period, then directly run sub zero coolant through it and once freezing go right back to WOT doing hundreds of hours of this cycle. Engineers don't mess around these days, engines are so much more reliabile today (especially mechanically) than in year before in most cases, though all the electronics and other complicated systems can obviously cause issues in some cases but the bones of engines these days are superior.

 

Tyler

[Crobinson16]

It goes to dealer tomorrow, but I'm sure i will get the " it's with in operating range" I have looked through some part numbers and I see the Camaro and Corvette with 6.2l both use a 194 degree thermostat vs the 207 degree in the trucks and they also share the same water neck so I'm going to be purchasing a set up to see how i like it. 

[mookdoc6]

22 hours ago, Crobinson16 said:

It goes to dealer tomorrow, but I'm sure i will get the " it's with in operating range" I have looked through some part numbers and I see the Camaro and Corvette with 6.2l both use a 194 degree thermostat vs the 207 degree in the trucks and they also share the same water neck so I'm going to be purchasing a set up to see how i like it. 

Let us know mine probably 205-210 as the highest I have seen it but does not maintain that temperature as it's brought down rather quickly.....

[Crobinson16]

1 hour ago, mookdoc6 said:

Let us know mine probably 205-210 as the highest I have seen it but does not maintain that temperature as it's brought down rather quickly.....

What truck do you have? 

[Crobinson16]

Okay, so to follow up. And to what I figured would be the outcome, tech didn't see anything of consern and took there demo truck out and it does the same thing. In anticipation of what I expected, I ordered the thermostat with housing from GM that is used on the Corvette and Camaro, it exactly the same set up but has a 194 degrees thermostat. Also Napa has the same setup available as well. Napa part states OEM uses a 207 degree for the truck but theirs is 194. So either will work if that's what your looking for. I'm going to install tomorrow if I have enough time.

[mookdoc6]

17 hours ago, Crobinson16 said:

What truck do you have? 

 

I have the 5.3L I know it's not apples to apples but surely has same T stat?

[Crobinson16]

Only thing in the system that can be a variable to this is the active grill shutters, the possibly could staying closed longer than nessary. I'd like to find a operation check of sorts.

[mookdoc6]

24 minutes ago, Crobinson16 said:

Only thing in the system that can be a variable to this is the active grill shutters, the possibly could staying closed longer than nessary. I'd like to find a operation check of sorts.

Never dawned on me to think of Active Grill Shutters on a truck?  Could be.....