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View Full Version : Engine near redline while pulling?



Jody
06-29-2005, 07:24
I am wondering if anybody else has this problem.

It only happens to me when im pulling long grades in 100 degree weather. Is it normal and is GM doing anything about it? I dont think the other guys trucks do this! Thanks in advance for all replies.

Jim Brzozowski
06-29-2005, 08:18
Need a little more info. What are you driving, what are you towing, how fast?

Are you talking engine rpm redline or water temp. redline?

DmaxMaverick
06-29-2005, 10:36
There is a direct correlation between the tach and your right bug stomper. For example, I can tow up a grade at 3000 rpm, or at 2200 rpm 2 mph slower. Absolutely, positively, 100% my choice.

Like said above, more details. If your truck isn't broken, you choose where you want your rpm, temps, noise, speed, and engine wear, among other things.

Jody
06-30-2005, 15:56
Sorry i wasnt more clear. I drive 02 chev crew cab dually. Im talking about coolant temp almost redlining at times out here in west texas. Im pulling 31' horse trailer with living quarters. Have it juiced level 2 in tow haul with the banks exhaust and amsoil air filter. Just wondering if mine is normal. Thanks!

Jim Brzozowski
07-01-2005, 08:43
Assuming its a Dmax, it has 3 thermostats that open in stages. I think the last one opens at 230. If its not showing more than that you're ok engine wise. I'd be concerned about the trans temp. if your running an Allison really hot.

DmaxMad
07-01-2005, 10:48
My 02 juiced level 1 pulling 32ft gooseneck carrying 2 jeeps about 13,000 lbs runs a tick below half way on gauge (210 i believe). Outside temp 95+. I would be concerned if it is near redline.

Buck
07-01-2005, 10:49
I thought the Dmax only had 2 thermostats??

kriskaza
07-21-2005, 06:32
I have a 04.5 duramax dually pulling a 13,000# horse trailer. I am experiencing the water temp gauge hitting the 240' mark when pulling up a 6% grade. The trany temp also increases to about 230'. The message center then reports an overheating condition. I turn off the A/C and ease off and the temp holds at 240'. This has happened when the outside air temp was 80' - 100'. I took the truck to the dealer to check it out. They say it's fine. I don't think so. I think it should be able to pull that load up a hill without overheating. Anybody have any suggestions?

Ranch55
07-21-2005, 13:04
Cool the transmission way down and the engine temps will also come down. I had the same issue and installed a BIG transmission cooler. It dropped my tranny temps down to 190~200 max and my engine temp does not get above what the thermostat is rated at now (~190 degrees).

Oilbrnr
07-22-2005, 14:48
Originally posted by kriskaza:
I have a 04.5 duramax dually pulling a 13,000# horse trailer. I am experiencing the water temp gauge hitting the 240' mark when pulling up a 6% grade. The trany temp also increases to about 230'. The message center then reports an overheating condition. I turn off the A/C and ease off and the temp holds at 240'. This has happened when the outside air temp was 80' - 100'. I took the truck to the dealer to check it out. They say it's fine. I don't think so. I think it should be able to pull that load up a hill without overheating. Anybody have any suggestions? Welcome to the club! This seems to be effecting a high percentage of LLY's when towing heavy in hotter weather. It has happened to me twice now.

Go have a look on the DP board. They (we) are going nuts over there, no root cause yet, no solution yet and no help from GM.

:mad:

Kennedy
07-22-2005, 16:29
Experiment underway...

mark45678
07-22-2005, 17:06
the engine temp that shows on the juice gauges say my truck starts to run warm (215 ~220 ) when pulling a long grade. at this point the clutch fan come on and stays on until the engine water temp drops to 190* again. I have NEVER seen the engine temps get hotter once the fan comes on! It may get hotter on longer up hill runs then I have been on but I have 57000 miles on it to date and 1/4 of those miles are pulling something! last week I did 1400 mile with a 30' 7700 lb camper from eastern MA to the middle of PA and back . Most of the highway speeds where 70~72 mph up hill ,cruise on when ever possible. the air temp outside was around 80~93*f depending on the time of day.

chipper
07-23-2005, 10:55
I have found on my 01 when pulling my 12,500 5er under the conditions stated above, if I run it against the governor in 3rd gear it starts heating, but if I back down to 2900 RPM it does not overheat. I remember years ago hearing my truck driver uncle talk about one of the diesel trucks that would overheat if run against the governor.

Badman40
07-26-2005, 16:07
My dump truck runs hot against the governor, back it off 200 rpms and it runs cool.

Jim Brzozowski
07-28-2005, 05:23
Buck, of course you are absolutely correct if talking about engine thermostats.

There are 2. Guess I may have included the turbo thermostatically controled valve as the 3rd one. Hope I didn't confuse anyone.

The thing I've noticed when towing a pretty good load even on flat land is that if I add 100 degrees to the reading of my outside air temperature thats where my trans. temp. runs, so that tells me the trans cooler which is out in front is only capable of reducing the transmission fluid temp. by that amount regardless of outside temp, so if its 120 outside I don't expect my trans. temp. to show less than 220. I don't really know where the limit is on the engine coolant temp. haven't seen mine go as high as some have reported.
I do know that the amount of bugs etc that have been engested by the coolers have probably downgraded their performance considerably, and unfortunately the flow of hot air from the trans. cooler goes right into the radiator, which doesn't help, and of course the more you mash the pedal the more heat has to flow from the turbo air cooler. Probably time for a good wash thru of all the coolers, on my truck anyway. I think its gonna be another long hot summer.

markrinker
08-01-2005, 05:34
Two words. Driving style.

Another two words. Slow down.

I might be wrong - there could be some underlying mechanical issues - but if you slow down and modify your driving style (expectations) for the hills and 6% grades, you'll extend the life of your truck and lower your stress level.

Personally, I'd accept whatever speed the truck will deliver with selector in 4th gear, tow/haul ON, at 2100-2300 RPM.

[ 08-01-2005, 02:32 PM: Message edited by: Mark Rinker ]

Jody
08-16-2005, 05:45
2 words bull s*** i dont hear the other guys who make trucks having this problem i think it is a design problem and gm should do something about it my brother has stock 02 that does the same thing with my trailer in same conditions come on gm u dont have a problem putting $40000 price tag on something make it right!

there is my 2 cents if anybody cares!

DarylB
08-16-2005, 06:18
BS? I think not.

Do you honestly expect the engine temp to stay at normal operating tempertaure (195-210) While the following apply?

#1 the engine is turning 3200+ rpms(near redline)
#2 You're going up a grade
#3 It's 100 degrees or hotter outside?

Its not possible to maintain that temperature, unless something changes (Less throttle, extremely lower air temp, etc)

Jody
08-16-2005, 06:20
it must be possible

f**d and d***e dont have the problem

Jim Brzozowski
08-16-2005, 08:37
If you're pulling the kind of trailer I think you are pulling you should be able to run 75 mph and not get over 235 on the coolant temp. Somethings not right. If you put it back to stock level does it still overheat?

Jody
08-16-2005, 12:56
im pulling 31 foot bloomer 4 horse

with 15 foot shortwall

truck does the same stock also

what do u pull