Jump to content

4L80e Overheating

Kratos707
 Share

Recommended Posts

Kratos707 Enthusiast

Kratos707

Posted
Posted

I was wondering if anyone has had this problem with there 4L80e transmissions. On my truck the transmission overheats when driving with no load on rather mild days (75 degrees F). My truck is a 2006 2500hd 6.0l 4x4 and I have an extra trans cooler in addition to the factory auxiliary cooler. Initially I was thinking that my coolers were plugged because the line coming from the transmission was hot and the line returning from the coolers was the same as ambient temp. Thinking that the coolers were plugged I tried flushing them, forward and reverse, I even removed them, and I still get that condition of one cooling line being hot and the other being cold. I started to think that maybe the cooling lines have a blockage so i flushed them as well (both forward and reverse) but still the same problem ( i also verified that the radiator did not have a blockage since the heat in the line is past the radiator). Since this did not work I took the truck in to have the transmission flushed just in case there was something going on the the transmission. The shop checkout the pan, filter and fluid and said it looked good (no metal shavings, minimal debris, not burnt). This shop used the HotFlush system to flush the system. Even after the flush the same problem.

 

The system is acting like the transmission is not letting the oil back into the transmission from the oil cooler return line. Does anyone here know what could be causing this? Outside of this issue the transmission is stock and is running fine.

 

please help

thanks

dewfpo Senior Enthusiast

dewfpo

Posted
Posted

Have you checked out the dash gauge to see if it's reading accurately?

 

Did this problem start all of a sudden or have the temps been climbing up over time?

 

What temps are you seeing?

DEWFPO

  • Like 1
Kratos707 Enthusiast

Kratos707

Posted
  • Author
Posted

Hi dewfpo, I have checked the dash gauge (confirmed the pan was hot with a temp gun). I recently bought the truck used and after about a month I noticed that temps were getting to the red zone on the temp gauge. After i did the transmission flush it seems like it worked for about a week before it started up again. Last night I flushed out the cooling lines (again) but still seems like no flow through the cooling lines.

 

I have hit the temp warning twice and it is not uncommon for the truck to have the trans temp around 220 when it is 75 degrees out side. (this is with both trans coolers and on the freeway going about 65 - 70 mph)

Raptordude Enthusiast

Raptordude

Posted
Posted

I would not drive the truck past 220 degrees anymore, if you test drive it and temps rise over 220, shut it down and let it cool

 

 

Sent from my iPhone using Tapatalk

dewfpo Senior Enthusiast

dewfpo

Posted
Posted

Hi dewfpo, I have checked the dash gauge (confirmed the pan was hot with a temp gun). I recently bought the truck used and after about a month I noticed that temps were getting to the red zone on the temp gauge. After i did the transmission flush it seems like it worked for about a week before it started up again. Last night I flushed out the cooling lines (again) but still seems like no flow through the cooling lines.

 

I have hit the temp warning twice and it is not uncommon for the truck to have the trans temp around 220 when it is 75 degrees out side. (this is with both trans coolers and on the freeway going about 65 - 70 mph)

 

Disconnect the atf inflow line to your trans (and put a hose on it into a pan) and have someone start it for just 5 seconds. You can then eyeball the flow coming out of the coolers and back into your trans to see if you have good flow, low flow or no flow.

 

Does the gauge and your temp gun come close when you compare them?

 

220F is not normal but it's not going to kill your atf either. If it gets to 240-250 then I would worry some.

 

You said you 'tried' flushing the coolers. Did you get good flow thru them?

 

DEWFPO

  • Like 1
Kratos707 Enthusiast

Kratos707

Posted
  • Author
Posted

DEWFPO, I actually compared the temp gun to the temp I was pulling from the OBDII and the it was pretty close. the gun read slightly lower but I think it was because the pan is a gloss black.

 

I will try the connection of the tube to the input line to measure the flow.

 

As for the flushing, the flow was really good I used an electric pump to to run oil from both directions. when running in the reverse direction I let the system run for about 15 minutes. I did this after I blew out the lines with compressed air.

Formulabruce Enthusiast

Formulabruce

Posted
Posted

When I install a Cooler, I REMOVE the stock one and replace it with a B&M super cooler and put it in its place. Its about twice as wide and 3X as high and twice as thick. I only add one L shaped bracket. I am Not an advocate of running coolers in series. Would like to see a picture of your cooler set up behind the grille.

Kratos707 Enthusiast

Kratos707

Posted
  • Author
Posted

So on my 30 mile drive home today I noticed that my trans temp did not go over 160 which is unusual cool temp for what I am used to. Once I got home I touched the return line and it is finally warm. I am not sure why it is now working but I am going to monitor let you guys know what happens.

 

As for the set up on my coolers is currently I am running one 11x11 derale cooler that is sitting to the passenger side of the GMC on the grill. I used to have it hooked up in series after the stock auxiliary cooler. After it runs okay for a while I am going to run a second 11x11 cooler (because I have a second one) but set up a parallel system. Not sure if it will work but I was going to set it up and see how it runs.

davester Senior Enthusiast

davester

Posted
Posted

maybe something finally broke free so you could get good flow through the coolers.

 

My truck, with the stock "HD" transmission cooler setup (through rad, then through aux cooler), I don't think I've seen it hit 90C (195F), even on a hot day driving around in traffic.

  • Like 1
Kratos707 Enthusiast

Kratos707

Posted
  • Author
Posted

Just wanted to give a quick update on my truck. The trans temp has been good for the last couple days and even when getting close to 90 out the trans is still running cool (not over 175 on the freeway). I bought replacement lines to swap out once I have time, but the only thing i could think of that was causing my problem before was a partial blockage at the inlet of the transmission (returning cool oil connection). That like you said Davester must have come free and allowed full flow again. This weekend is going to be near 100 and I will check how the transmission runs.

 

thanks all for the help with this!

davester Senior Enthusiast

davester

Posted
Posted

Should have included this with the previous post, but you can either:

a) go to the dealer with your vin, and they'll sell you the right lines

 

b) ask for the build sheet from a dealer (or various online sources of it, should be able to do it for free) or you can decode the RPO codes on the sticker in your glove box. It's a long list of all the options for your truck, and it's useful to find the right parts for your truck, as there are options that make a difference as to what parts you need to buy (transmission lines, brakes are two I know of offhand).

 

If you don't have to have the parts right away, buy them online from places like rockauto.com (and use their 5% discount code available all the time), generally significantly cheaper than local parts stores..

 

And for doing the transmission lines, don't forget to also buy replacement retaining clips, as they are single-use (you will need either 4 or 6 depending on if you have the HD tranny cooler and if you replace all the lines).

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • richard wysong
      Electrical Problem - solved

      By richard wysong · Posted

      Thanks for posting, I'm sure it will help someone
    • Brendan C
      2026 6.6 L5P oil cooler leaking oil at 4,000 miles

      By Brendan C · Posted

      New to diesel trucks. I happened to find my oil cooler leaking oil externally with only 4,000 miles on the truck. I didn’t realize this was an issue until I started researching it. Dealer is going to replace it under warranty but I’m wondering if there’s anything GM is working on to fix this issue. I’ve heard the oil filter used is the same as they use on their V6 motors and that’s what is causing the problems. Should I switch to a bigger filter or keep using the OEM recommended? 
    • Vu1can
      Seems to be Missing a lot of Updates

      By Vu1can · Posted

      So, GMCustomerService:  Judging by the Update History pictured above, is this truck missing any updates that it actually needs. If it's just for the infotainment system, the radio is working fine and no trouble with SeriusXM. and Android Auto is working fine wirelessly with my phone. Some months ago, an update notice was sent to my truck. I approved the update and it finished saying that the update was successful, but it seems that whatever that update was, it didn't actually get installed - at least not if I'm to go by the Update History shown above.   So, again, are there any updates that this truck really should have? I've checked with my dealer but they're reluctant or commit to anything and if I want them to check, they require a $200.00 fee just to check it out and then I'd have to pay for the actual update(s).    Ignorance is bliss, and if none of the updates goes to fixing any mechanical discrepancies, I'll just leave things as is.  
    • CNH-320
      Electrical Problem - solved

      By CNH-320 · Posted

      Hey everyone, I recently had an issue with my 07 2500HD GMT900. My DRL’s stay on at all times. Right front turn and right mirror turn signal indicator stay on solid at all times. By “at all times” I mean the only way to make them go off is disconnecting the battery. I tore the headlight assemblies out, tried disconnecting the harnesses to eliminate bad wiring at the harness, I unplugged the headlight switch, no change and the mirror turn signal still stayed on. My first thoughts were : Bad bulb and/or socket somewhere, under hood fuse panel bad, bcm bad, tail light or trailer wiring problem, or some random short to power in the harness.  Possibly a bad ground but unlikely. I had a big clue in the fuse panel, it had a burnt smell. I started pulling every fuse that had to do with DRL or right turn/park lamp. Nothing made the right directional turn off but pulling the DRL2 fuse made the DRL’s go out.  After studying wiring diagrams, I found that both problems had that fuse panel in common, the bcm also controls both problems but knowing the fuse panel had a burnt smell I removed and disassembled the fuse panel and found a little corrosion on the printed circuit board.  I ordered a new fuse panel from Amazon for like $260. When it arrived I installed it, and put everything back together, the problem was fixed. I figured the fuse panel needed to be replaced anyway so that was a logical place to start. Hopefully this story helps someone in the future. Regretfully I didn’t scan for codes before I did everything.
    • 2022LtTbZ71
      Service 4wd, ESC light, traction control light on, Service charging system (vehicle may stall)

      By 2022LtTbZ71 · Posted

      That stinks. I’m sitting on the side of the road right now with the same issue. Never had an issue before taking it in for the ground strap recall. Now I’m outside of warranty and they’ll probably want $200 just to diagnose what they already “fixed”. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...