6L80 running hot, no symptoms. Thoughts?

[John18A]

So I've tried to research this before posting, sorry if I have missed anything. I have a 2013 Suburban Z71, 172,000, all original drivetrain with the towing package with auxiliary cooler. On a flat interstate, 75 mph, not towing, no load, in 85 degree temps, I am running a consistent 216 degrees according to the DIC. If I hit any hills, it will creep up. Transmissions shifts just fine, no other symptoms.

Took it in to a local shop for transmission service. He flushed the fluids, said there were no blockages in the cooling system, but found a small amount of metal particles on the magnet. No change.

Should I worry about this? Is this excessively hot, or am I over thinking it?

Thanks!

John

 

[j91z28d1]

I don't think anyone would call 216 excessive but for not towing and flat cruising it does seem higher than normal. to me.


what to do about it? I don't know. but from reading this board, a completely untouched tranny at almost 180k miles, is actually higher than average mileage for the torque converter cluches to go out and put a bunch of metal thru the tranny.

I'd you're a diy guy, it might be worth changing the tc, flush the system and hope. if not, probably more cost effective to just drive it till tranny goes and replace it all at once.

 

[swathdiver]

So I've tried to research this before posting, sorry if I have missed anything. I have a 2013 Suburban Z71, 172,000, all original drivetrain with the towing package with auxiliary cooler. On a flat interstate, 75 mph, not towing, no load, in 85 degree temps, I am running a consistent 216 degrees according to the DIC. If I hit any hills, it will creep up. Transmissions shifts just fine, no other symptoms.

Took it in to a local shop for transmission service. He flushed the fluids, said there were no blockages in the cooling system, but found a small amount of metal particles on the magnet. No change.

Should I worry about this? Is this excessively hot, or am I over thinking it?

Thanks!

John

John,

How long after you got up to cruising speed did you take this temperature reading?

Do you have a lift and oversized wheels and tires?

I would say she is quite hot and that you ought to have the flow rate of your cooler tested with the TransFlow machine which GM dealerships have.

I'll caveat the above statement by saying that to me, the temperature seems abnormal for a healthy, stock truck. These trucks can easily handle this temperature however. The warning don't come on until over 260 degrees.

Here are photos from mine from 2018-2020. The last one, she was towing a lightly loaded 12-foot U-Haul trailer. Today, at 218K miles, she runs about 5 degrees hotter in the same temperature and she's at the end of her fluid change interval.



These photos are taken after being at speed on the highway after about 30 minutes.

 

[Foggy]

IMO 216* is just too hot at the conditions you described.
How is your coolant temp when this happens??? You'll need something
OTHER than the factory gauge to tell you the Real Temp !!!!!
If trans is original, My Guess would be the torque converter clutch is
going, if not already gone and just not locking up... That will produce excess
heat by itself...
So, You'll need a decent scan tool to tell your RPM slip when TC is commanded ON
and to check the real temp of your cooling system.. Your radiator/water pump/ t-stat
could be the actual issue

 

[swathdiver]

IMO 216* is just too hot at the conditions you described.
How is your coolant temp when this happens??? You'll need something
OTHER than the factory gauge to tell you the Real Temp !!!!!
If trans is original, My Guess would be the torque converter clutch is
going, if not already gone and just not locking up... That will produce excess
heat by itself...
So, You'll need a decent scan tool to tell your RPM slip when TC is commanded ON
and to check the real temp of your cooling system.. Your radiator/water pump/ t-stat
could be the actual issue

I can see torque converter slip with the Torque Pro app on my phone and the OBDII adapter.

 

[John18A]

Wow thanks guys, all great information. I'll definitely check out the Torque Pro app. Sounds like a great tool to have for a lot of reasons.

I have a small spacer lift with Bilstein 5100s. Tires are 275/70R18s, KO2s. Those temps were taken after about 30 minutes of driving, and I stayed on the interstate for at least another 30 minutes with no change in temp.

John

 

[Trilla_one]

John,

How long after you got up to cruising speed did you take this temperature reading?

Do you have a lift and oversized wheels and tires?

I would say she is quite hot and that you ought to have the flow rate of your cooler tested with the TransFlow machine which GM dealerships have.

I'll caveat the above statement by saying that to me, the temperature seems abnormal for a healthy, stock truck. These trucks can easily handle this temperature however. The warning don't come on until over 260 degrees.

Here are photos from mine from 2018-2020. The last one, she was towing a lightly loaded 12-foot U-Haul trailer. Today, at 218K miles, she runs about 5 degrees hotter in the same temperature and she's at the end of her fluid change interval.

View attachment 469378View attachment 469379View attachment 469380View attachment 469381View attachment 469382

These photos are taken after being at speed on the highway after about 30 minutes.

My RPMs used to be below 2k like yours anywhere between 70 and 85mph. Ever since I did a trans drain/fill and filter service 7 months ago, i'm over 2k. My oil pressure made the same jump from just under 40psi to just over. It didn't start doing this right after the service. It started after I made a 300 mile trip the following week. Transmission temp is in the 180s to 190s around town and up to 215 after driving 1hr+ on the highway under 70mph. Picture is after 10 minutes on the highway then getting off. Before the service I never saw it above 175.

I thought something got loose in the fluid change and was causing a restriction so I went back to the shop that did the service. They checked and couldn't find a problem. They said there is TC lockup and no TCM codes so nothing they could do. Truck drives the same albeit a little rougher due to the higher RPMS at those speeds so I keep it at 65mph now, which is just about 2k RPMS.

My CEL is P0430/P0420 for both cats. I'm not sure if that is related since i'm going on over a year with them on. I plan to swap them out next.

Trans is at 248k and still shifts as normal as can be expected with a 4l60.

 

[Marky Dissod]

... '13 Suburban Z71, 172,000 miles, all original drivetrain with the towing package with auxiliary cooler.
On a flat interstate, 75 mph, not towing, no load, 85F, I am running a consistent 216F according to the DIC. If I hit any hills, it will creep up.
Transmission shifts just fine, no other symptoms.

Took it in to a local shop for transmission service.
He flushed the fluids, said there were no blockages in the cooling system, but found a small amount of metal particles on the magnet. No change.

Should I worry about this? Is this excessively hot, or am I over thinking it?

If your 6L80 has made it 172,000 miles, and has not yet been suicide bombed by the torque converter's clutch,
you may want to seriously consider a torque converter replacement/upgrade, before the aging clutch fails & takes out the entire 6L80 with it.

 

[swathdiver]

My RPMs used to be below 2k like yours anywhere between 70 and 85mph. Ever since I did a trans drain/fill and filter service 7 months ago, i'm over 2k. My oil pressure made the same jump from just under 40psi to just over. It didn't start doing this right after the service. It started after I made a 300 mile trip the following week. Transmission temp is in the 180s to 190s around town and up to 215 after driving 1hr+ on the highway under 70mph. Picture is after 10 minutes on the highway then getting off. Before the service I never saw it above 175.

I thought something got loose in the fluid change and was causing a restriction so I went back to the shop that did the service. They checked and couldn't find a problem. They said there is TC lockup and no TCM codes so nothing they could do. Truck drives the same albeit a little rougher due to the higher RPMS at those speeds so I keep it at 65mph now, which is just about 2k RPMS.

My CEL is P0430/P0420 for both cats. I'm not sure if that is related since i'm going on over a year with them on. I plan to swap them out next.

Trans is at 248k and still shifts as normal as can be expected with a 4l60.

View attachment 469408

View attachment 469409

View attachment 469410

View attachment 469411

View attachment 469412

View attachment 469413

Those RPMs are normal for a 4-speed truck with stock size tires and 3.73 gears. The trans temp may also be normal for that cruising speed, depending on the ambient temp.

Get a new Y-Pipe and cats as soon as you can. I went with a Magnaflow Y-pipe and cats almost eight years ago, still running strong. Before you spend the coin on that, make sure you have no large exhaust leaks before the cats and that the O2 sensors are screwed all the way in. BTDT!

 

[Trilla_one]

Those RPMs are normal for a 4-speed truck with stock size tires and 3.73 gears. The trans temp may also be normal for that cruising speed, depending on the ambient temp.

Get a new Y-Pipe and cats as soon as you can. I went with a Magnaflow Y-pipe and cats almost eight years ago, still running strong. Before you spend the coin on that, make sure you have no large exhaust leaks before the cats and that the O2 sensors are screwed all the way in. BTDT!

Thanks for the insight and recommendations. Someone else recommended Magnaflow as well so I may go that route.