Engine Temp And Trans Temp Too High

[smattei14]

Hey guys...I have a 2006 GMC Yukon Denali....

 

This is the 1st time I towed with it. I towed my 6000 lbs boat from MD to PA...so there were some hills and it was pretty hot out (around 85 with about 80 to 90 % humidity)

 

When I was just sitting in traffic the engine temp was around 210...alittle to high for my liking..once i got moving the temp settle down around 190-200.

 

The trany temp on the other hand was around 200...in fact it got to 230 when i was back up the boat up the driveway in reverse. On the road (when moving) it did not go past 200. When sitting it was around 210-220 (a little too high for me).

 

When I got done backing it up the driveway, I always let the engine cool down (or get back to op. temp). When I let it idel for 10 mins, the engin temp was at 210-220 and the trans temp was at 210-230.....

 

both way too high for me....

 

Since I have the electric fans (good for MPG's but does not cool the engine/trans as good). I think I will have to replace the trans cooler for a bigger one 10x11 or 11x11 (not sure what size)?

 

I think I will have to lower my temp that the fans come on, or get a new set of aftermarket fans?

 

In the end..I am not sure what I should do here....I need your help....Thanks in advance!

 

FYI...the 6.0 rocks...I had a 5.7 before (1996 Chevy Suburban)....there is so much power behind the Denali that is it scary....

[C & A s Dad]

You are on the right track. Your issue is the e fans are set to come on at a specific temp. I am not sure what that temp is but it is pretty high. I do not know a great deal about a custom tune but I know you can have a PCM tuned to turn the fans on and off as you like. You can also buy a Hand Held unit such as a Hypertech, Superchips or Diablo that will allow you to adjust your fans. Do your homework on this. The Custom Tunes will typically offer better performance but IMO are not as convenient. If you are not looking for a significant boost in perf and primarily want to adjust your fans, the Hand Held would be the way to go. You will likely read other opinions on this subject.

 

On the cooler. Becasue of the winter climate where you live, I would suggest you increase the size of your cooler only one step or possibly two. The OE cooler is approx 5" x 11" x 3/4" thick. It is designed to work on trucks that operate in South TX and Minnesota so they have to use a "happy medium". Where I live I upgraded to a 11" x 11" x 3/4" stacked plate cooler which is the same design as the OE just twice as large. I am running mid 160 temps on a 95 degree day pulling a 6500 lb camper. You should consider a 7" x 11" x 3/4" or a 9" x 11" x 3/4. If you go any larger, you would likely have to install a thermostat or partially cover the cooler on those 10 degree days. It is difficult to overcool trans fluid but you do want it to get warm enough to be "fluid" so it will flow well.

 

I would agree with you. Anything over 200 on the trans temps is too high IMO.

 

If you decide to upgrade. Send me your e mail address and I can send you some good pics of my cooler installed and some tips on what I did. Be sure you buy a stacked plate designed cooler vs the old tube and fin design.

[smattei14]

You are on the right track. Your issue is the e fans are set to come on at a specific temp. I am not sure what that temp is but it is pretty high. I do not know a great deal about a custom tune but I know you can have a PCM tuned to turn the fans on and off as you like. You can also buy a Hand Held unit such as a Hypertech, Superchips or Diablo that will allow you to adjust your fans. Do your homework on this. The Custom Tunes will typically offer better performance but IMO are not as convenient. If you are not looking for a significant boost in perf and primarily want to adjust your fans, the Hand Held would be the way to go. You will likely read other opinions on this subject.

 

On the cooler. Becasue of the winter climate where you live, I would suggest you increase the size of your cooler only one step or possibly two. The OE cooler is approx 5" x 11" x 3/4" thick. It is designed to work on trucks that operate in South TX and Minnesota so they have to use a "happy medium". Where I live I upgraded to a 11" x 11" x 3/4" stacked plate cooler which is the same design as the OE just twice as large. I am running mid 160 temps on a 95 degree day pulling a 6500 lb camper. You should consider a 7" x 11" x 3/4" or a 9" x 11" x 3/4. If you go any larger, you would likely have to install a thermostat or partially cover the cooler on those 10 degree days. It is difficult to overcool trans fluid but you do want it to get warm enough to be "fluid" so it will flow well.

 

I would agree with you. Anything over 200 on the trans temps is too high IMO.

 

If you decide to upgrade. Send me your e mail address and I can send you some good pics of my cooler installed and some tips on what I did. Be sure you buy a stacked plate designed cooler vs the old tube and fin design.

 

 

sounds great...my e mail address is [email protected]

 

As for the trans cooler...why should I get a stacked plate vs the old tube and fin design?

 

I am only wnat to turn on my fans at a lower temp..not worried about performance.

 

I heard that there are aftermarket fans that I can buy that cool better then the OEM fans provided by GM? I am use to the old school temp at 190/200 and trans temp does not move past 180...this idea of ele. fans is great for MPG, does not sit well with my stomach when I tow and produce alot of heat.

[C & A s Dad]

Stacked plate coolers are much more efficient in their design meaning a 5 x 11 sp cooler would cool as well or better than an old style tube and fin cooler 30 to 40% larger. The sp coolers are also much less restrictive to the flow of the fluid.

 

If you are interested in lowering fan temps and not looking for all out perf, I would look into the hand helds. I have a Hypertech Max Energy and so far I am very pleased.

 

You are correct about the e fans. Take a look under the hood of any brand 3/4 or 1 ton truck and you will find a fan clutch and a monster fan pulling some serious air through the radiator.

 

I have often said I have to set an orange traffic cone in front of my truck when it is idling in the campground so small children and pets will not be pulled into the grille.

[rckt442]

Ditto on the trans cooler suggestion. I removed the factory cooler and replaced it with the 11" x 11" stacked plate design (Hayden brand). It brought the temps down to a reasonable level (180 - 190 F). I have the 4L70e transmission. Not sure which one is in your truck, but it may be the same one since I also have the 6.0 liter engine.

 

See this thread for pics of my installation. trans cooler install

 

I have a different opinion about the engine coolant temperature. I think that 210 is normal for these engines. Even when I'm not towing, my temp gets that high. If you're using the analog gauge on your dash to read the temp, then who knows what it really is. Those things are way off, especially on the low and high end of the scale.

 

If you get a programmer or some other method of lowering the temp that the fans come on, you should also see a reduction in trans temp while sitting in traffic and at low speeds, when the fans are likely to be running.

[bobf1234]

Sorry to take this a little offtrack... I just want to clear this up for myself... Doesn't the Denali have the 6.2?

[smattei14]

Sorry to take this a little offtrack... I just want to clear this up for myself... Doesn't the Denali have the 6.2?

 

 

no worries...the 2007 has a 6.2 (I am pretty sure).

 

the 2003-2006 has the 6.0

 

Thanks for the help...I think I have a new saturday project!

[C & A s Dad]

Sorry to take this a little offtrack... I just want to clear this up for myself... Doesn't the Denali have the 6.2?

 

 

no worries...the 2007 has a 6.2 (I am pretty sure).

 

the 2003-2006 has the 6.0

 

Thanks for the help...I think I have a new saturday project!

 

 

 

Remember, your "A" bracket on your 06 is going to look like the pics I sent you. Todd's is a 900 series NBS and his is configured a little different making is difficult to mount the cooler to the "A" bracket.

 

Also, you had asked in another thread if your Denali had an engine oil cooler. I cannot be sure but I believe it does. The 2500 series trucks with a 6.0 do have an oil cooler but I just am not sure about the Denali.

[Mikeee]

This web site has a large selection of trans cooler.

http://www.transmissioncoolers.us/Merchant...e=tru-cool-thin

 

See the built-in temp bypass feature?

[smattei14]

Thanks for the info....

 

I think I am going to go with a 7 or 9 x 11 3/4 thick stacked plate cooler.

 

Do you have any name brands or model numbers that you guys have tried and work good?

 

how easy of a project am I looking at here...or should I have a deal do this?

[C & A s Dad]

I try not to seem like I am selling on this forum but I will provide you our part #s if you are interested. The 7.5 x 11 x 3/4 stacked plate cooler in CARQUEST Brand is a 77421 and the 9.5 x 11 x 3/4 is a 77422. I would think the 9.5 x 11 is what you want. These are supplied to us by Hayden but we use our own part numbering system. You can get the Hayden #s from their website if you need them. I would also recommend the 77018 access kit. It includes some flat steel brackets and mounting hardware that are very usefull in mounting the cooler to the "A" bracket. If you do not have a CARQUEST Store in your area, NAPA handles the same brand but under their name and I believe O'Reilly handles Hayden under the Hayden name.

 

To my knowledge, these stacked plate coolers are all supplied by one mfg. In other words, Hayden does not mfg them. You will be fine with any reputable brand but I would strongy suggest the 3/4" thick models over the 1.5" thick models. Hayden does not even offer the thicker models any longer because they are not as efficient. GM also made this move in 99 with the 800 series trucks.

 

 

I forget who all I have sent my pictures to but if I have not sent them to you, PM me your e mail address and I will send you about 8 good shots of mine installed with some installation tips.

 

The project is not bad at all as long as you can remove the grille assy. I am not sure about a Denalli but my grille can be on the ground in less than 5 minutes.

 

I will add that the measurments I provided are overall measurments. You will also notice if you look at the website provided in an earlier post, the Tru cool LPD cooler pics look exactly like the Hayden Trans saver cooler pics which can be seen on the link at the bottom of the Tru Cool page.

[Gray Ghost]

Without towing anything...the tell tale computer reads my trans temp at 185.

[zeaux6]

I just replaced the aux trans cooler on my 2008 Suburban with a Hayden trans cooler. It was the 11 x 11 sixe and it has made a dramatic difference. I live in Houston and just this past weekend towing my 6700 pound boat the trans temp never got above 175 and settled around 165 on average. Before the install I would see 200+ all the time.

 

The toughest part was mounting the cooler to the front of the truck. I used the A-frame and got creative with some heavy duty zip ties. Also I had to remove the factory threaded fittings that screwed into the factory cooler, flared the ends slightly and clamped the hose that came with the cooler.

 

Easy enough project, and well worth the effort.

 

Mike

[C & A s Dad]

You have done the right thing considering where you live. IMO the OE cooler is too small for serious towing in our part of the world.

 

I have a Hayden 11 x 11 stacked plate cooler and it keeps my fluid nice and cool towing my camper on those 95+ degree days.