01 1500HD 4L80E Overheating issues

[THEFERMANATOR]

If I understand you correctly, you're radiator cooler is no longer hooked up? If so this is a huge no no unless your air cooler has it's own electric fan on a temp switch. Your radiator is there for slow speed cooling when you're going under 50 and don't have enough airflow to force air through the cooling stack. For the other questions, they should go to your builder. He could have swapped internal shafts which can cause some serious problems. For the 97+ there is some differences internally in the shaft spacing that can lead to large internal leaks if you don't pay attention to the atsg manual. It sounds like it wouldn't be a bad idea to get a pressure gauge on it and see what it is doing. SMALL changes in line pressure can make a BIG difference in shift feel. Last one I did I ended up pulling the transgo boost valve spring out and putting the stock springs in with the transgo valve because it was shifting so harsh going into gear. The stock springs lowered idle line pressure from 70 to 50 and stopped the banging into gear and made it shift smoothly instead of like a locked out 400. And looser converters play a big role in shift feel as you said you now have a 2200-2400 stall where the stock was 2000 iirc for a 6.0l.

 

[WarWagon]

Sorry guys moving a bit too qucik here between post. So the snap on scanner is reading TCC SLIP SPEED up to 500rpm while i am starting from a stop 0MPH-60MPH once i get up to 60MPH and its in final gear TCC locks up and scanner now reads 0-3rpm slip ONLY when the TCC locks up. I will try later on today and check my TCC Slip going up a hill.

Slipping even on the Torque Converter should have the trans enter limp mode and set a code. May not trigger a SES light.

IF the engine is not running properly the ECM will unlock the TC Clutch. Misfire etc. Reduces emissions and allows the engine to recover or not stall. A stuck open T Stat may be causing you to run so bad it keeps the TCC unlocked.

Diesel Driver the answer to your question yes offroaing will easily get my transmission up to 200F and now im starting to understand why because of a lower speed driving.

You have a trans cooling problem where conditions, including extra heat generation from a higher stall converter, combine to make it show up.

WarWagon I'm taking in and understanding what your explaining, its ringing a light in my brain, By any chance were you ever involved in working on aircraft? The term windmilling ringed in my heat from my aircraft class. I'm going to do replumb my trans cooler setup how you explained so in terms of aerodymanics of the heated air hitting the clutch fan thermal spring, "Cause and Effect".

Diesel and AVGas runs in the family. @THEFERMANATOR also explained it in MPH terms for Ram Air going through the stack. (This also applies to A/C: engine fan not needed above 45 MPH.)

What do you mean by routing trans fluid through cold side of radiator? the very lower fitting closets to the floor is the cold side or the one closer to the hood.

Think about how the "heat" generated in the transmission gets to the radiator core to be dissipated into the air. Hot trans oil is going into coolant that's already "cooled" by the radiator core. So the transmission heated coolant has to travel through the engine to be dissipated to the air in the radiator core. The hot side of the radiator with hot coolant from the engine would not cool oil so well because it's hot.

That said: think about the hot oil from the transmission. Make sure you know what cooler line is pumping "out" of the transmission. That needs to go to the "bottom port" on the radiator to purge air out of the trans oil heat exchanger (radiator trans oil cooler). Then after it's "cooled down some" the oil goes to the air to oil cooler for additional cooling. IMO purging air is not a concern in oil coolers looking at most bottom port designs.

The critical thing here is the hottest oil hits the radiator heat exchanger first. Otherwise you have hot air from the air to oil cooler blasting the A/C condenser and then the cooled trans oil possibly being reheated in the radiator.

I am now considering the possiblilty of keeping my clutch fan and changing over to durmax style clutch fan.

Put a ACDelco fan clutch VIN matched to your truck on it and call it a day.

Maybe an aux pusher fan if the advice still has you running hot.

Aftermarket fan clutches can be a light duty unit by mistake.

Diesel may be the wrong temperature/"duty" and suck fuel/power by staying locked in when it's not needed.

Also when you were saying cold brake stand? what are you suggesting i do or don't do when cold starting in the morning prior leaving to class? I usually wait 2mins before taking off and letting my engine warm up and trans while driving.

Cold morning and the windshield is frosted up. I don't have time for this window scraping $hit and the 'ignorant override you design assumes engine warmed up' defrost kicks in A/C compressor and frosts/fogs it back up. Dew point near or slightly below freezing. Just dew point alone at low temp is rough to keep cold windshield clear of fog.

This problem has had some solutions thrown at it. GM burned some trucks to the ground over heated windshield washer fluid and then issued a $50 check to "remove" the feature on 2008 models.

So to defrost the windshield and keep it from frosting back up:
1) Put a 120V electric heater in the cab on a timer 1 hour or more before you got to leave.
2) Use a block heater for the coolant.
3) Drop it in drive, stand on the brakes, and give it as much throttle as it will take before the rear wheels break loose. 2 Min max at a time or you are overheating the trans oil in the TC.

4) Park it in a warm garage...

The ECM is instructed to "Warm Up" the emissions equipment as fast as possible. Warm Up... Do you think sitting around with no-load at 1200+ RPM is better than "loaded" dropping it in drive and going? (Although gently: without WOT.) It sure burns more fuel going nowhere. I wait for oil pressure then drop it in drive and go. Now that I am not my own warranty station - no warning lights and then drop it in drive as I only have a 6+ PSI switch for oil pressure now anyway.

Also almost forgot the answer to your question about my engine temperature dropped down fro 209F to 150F when i was climing up the snowy hill. I have not yet verifyed the accuracy of the engine temp gauge will do that later on today but the snapon scanner does match the temp as it says on the dash for trans temp. Talking about gauges reminded me that my entire instrument cluster is not OG the owner i brought it from had put in a escalade dash i been meaning to send it out to someone to get it fully rebuilt due to my engine oil pressure gauge needle bouncing around while crusing speed

Does the scanner show oil pressure? Coolant Temp?

Verify grounds by cleaning them. Battery grounds and the like. Load test battery. Positive battery cable condition?

Yeah the gauge may be bad or sender. Put a mechanical pressure gauge on it and be sure what is really going on. Last oil and filter change? Any UOA done?

What engine this have anyway?

 

[Manny1500HD]

So i went ahead and brought a engine oil and transmission oil pressure gauge kit from harbor freight. I drove the truck locally with the gauge. I have some gopro videos that this forum won't let me post if you guys want to see the video message me your email and I'll send it. When the truck is idiling the gauge reads about 40-45psi. When i shift into reverse goes up to 90psi, now i'm not sure if this is within specs but when i step on the pedal to back up in reverse for example up to 2,000rpm the gauge will start to read about 300+psi it bounces like crazy.

When i shift into drive the gauge reads bout 55psi at idle, when i start to move it will go up to 90psi in neighborhood street driving when i turned to the main road and got on the pedal not too crazy, gauge read up to between 120-130psi most of the time. "BUT WHEN I SAW THAT THE PRESSURE WOULD DROP TO 90 THEN AND SHIFT INTO HIGHER GEAR" is it supposed to do that?. I went WOT several times to see if it would get near 150psi or above it and wouldn't. Highest i ever saw it read at some point was 145psi while the transmission temp was 160F. I still have yet to plug scanner and check TCC Slip going up a hill.


WarWagon: The snap on scanner shows engine coolant pressure but not engine oil pressure i don't think the computer has that setting in it for the year model. it does not show transmission pressure also. I did put a gauge in it to verify the gauge in dash and the gauge was reading steadily compared to the one in the dash. that was 2 years ago, i always do my maitenance on my truck ever since i brought it.

It has a 6.0L LQ4 engine in it no performance modifications in it for now. bone stock. I'm also planning on changing the oil pickup tube bracket that holds it in place with 2 bolt holes and not one hole, along with the o-ring. The oil filter changes havent made a change in the way it reads although lately been reading just a bit lower compared to last year gonna do oil pump change as well.

The transmission i havent drain the fluid and change filter since i installed it 2,000 miles on it.

 

[dbrannon79]

the trans pressures are controlled by the PCM. what trans did this truck have in it originally? if a 4l60E you may need to have the PCM tuned for the 80e tranny. Here is a screenshot of the trans pressure tables from my obd1, that might give you an idea on what pressures you should be seeing. these pressures won't be the same as yours but should be in the ball park since these tables are for the 1995 4l80e tranny

 

[Manny1500HD]

the trans pressures are controlled by the PCM. what trans did this truck have in it originally? if a 4l60E you may need to have the PCM tuned for the 80e tranny. Here is a screenshot of the trans pressure tables from my obd1, that might give you an idea on what pressures you should be seeing. these pressures won't be the same as yours but should be in the ball park since these tables are for the 1995 4l80e tranny

View attachment 70010

View attachment 70011

My truck came with with 4l80e originally. i swapped it out for a diesel 4l80e not sure what year to be exact but def a late model case as it has the transmission lines futher apart from each other. Looking at the charts after im done typing this.

 

[THEFERMANATOR]

the trans pressures are controlled by the PCM. what trans did this truck have in it originally? if a 4l60E you may need to have the PCM tuned for the 80e tranny. Here is a screenshot of the trans pressure tables from my obd1, that might give you an idea on what pressures you should be seeing. these pressures won't be the same as yours but should be in the ball park since these tables are for the 1995 4l80e tranny

View attachment 70010

View attachment 70011

These values are what is commanded of the EPC, not line pressure. And your obd1 diesel values are quite different from his 01 6.0l.

 

[THEFERMANATOR]

So i went ahead and brought a engine oil and transmission oil pressure gauge kit from harbor freight. I drove the truck locally with the gauge. I have some gopro videos that this forum won't let me post if you guys want to see the video message me your email and I'll send it. When the truck is idiling the gauge reads about 40-45psi. When i shift into reverse goes up to 90psi, now i'm not sure if this is within specs but when i step on the pedal to back up in reverse for example up to 2,000rpm the gauge will start to read about 300+psi it bounces like crazy.

When i shift into drive the gauge reads bout 55psi at idle, when i start to move it will go up to 90psi in neighborhood street driving when i turned to the main road and got on the pedal not too crazy, gauge read up to between 120-130psi most of the time. "BUT WHEN I SAW THAT THE PRESSURE WOULD DROP TO 90 THEN AND SHIFT INTO HIGHER GEAR" is it supposed to do that?. I went WOT several times to see if it would get near 150psi or above it and wouldn't. Highest i ever saw it read at some point was 145psi while the transmission temp was 160F. I still have yet to plug scanner and check TCC Slip going up a hill.


WarWagon: The snap on scanner shows engine coolant pressure but not engine oil pressure i don't think the computer has that setting in it for the year model. it does not show transmission pressure also. I did put a gauge in it to verify the gauge in dash and the gauge was reading steadily compared to the one in the dash. that was 2 years ago, i always do my maitenance on my truck ever since i brought it.

It has a 6.0L LQ4 engine in it no performance modifications in it for now. bone stock. I'm also planning on changing the oil pickup tube bracket that holds it in place with 2 bolt holes and not one hole, along with the o-ring. The oil filter changes havent made a change in the way it reads although lately been reading just a bit lower compared to last year gonna do oil pump change as well.

The transmission i havent drain the fluid and change filter since i installed it 2,000 miles on it.

Your line pressures sound pretty close off the top of my head. Your line pressure in reverse 9n the pedal sounds a bit high, but not out of spec depending on what mods were done(the transgo valve hd2 says it runs upwards of 370 in reverse).

 

[Manny1500HD]

I spoke to Jake's transmission and asked them what is the recomended overall shift pressure he told me depends on HP . i told him its a stock 6.0L with "REBUILT" transmission with their rebuild kits he was saying 120-130psi is too low, that theres internal pressure leak, mabye the clutch seals.

"DAMNIT" not sure what to do now i have a car i need to tow this thursday. $2,700 in the toilet. I start school on January 10th, I'm gonna have to go back to driving my 1967 bug untill i fix this issue. What should i do? I'm going to get my trans up to operating temp and check fluid level and top it off top the second highest line in hot level and probably just hope for the best but not very confident if that doesnt work. Gonna have to drop the pan and check if anythings visible from the pan.

I think trans guy messed up. NO WARRANTY. when i drop the pan i better see the parts i provided in the rebuilt kit. Pretty furious right now wnna chuck a BFH across the shop I did think i could probably crank up the shift pressure with my superchips tuner but won't matter much if its just gonna leak more psi right?

 

[MrMarty51]

If they messed up a clutch pack piston seal when they put it together, they then should be the ones to fix it.
Apparently the person doing the rebuild did not check each clutch pack with air pressure when they were assembling the transmission.
If they had, they would have caught that leaking seal.

 

[Manny1500HD]

So i just dropped the pan here do you guys think some of this stuff in the pan is normal? i did see alot of shiny particles in transmission fluid very fine particles.



I also took a picture of the valve body any idea what year this narrrows it down to?

 

[MrMarty51]

Is that a check ball on the end of that magnet ?

 

[Manny1500HD]

No not a ball check just a magnet on the other end of my snap on flat head. that some stuff it pulled out from the magnet also i relaized that the magnet was not in the correct location where stock recomended