2020 Tahoe Help - Limp Mode

DOUG75 · May 30, 2021

I haven't had any good luck for a while now. The wife went to town last night; about a 1 mile away and almost didn't make it back.

A 2020 Tahoe with 12,000 miles went into limp-mode at the bottom of the driveway, again, a short trip and the engine wasn't even hot.

Checked the oil, right where it should be, and it was changed a few months ago.

A few weeks ago we were at a dealer and said that we thought the transmission might be doing something strange and they test drove it with ultra soft care (like it hade a 20hp engine).

We don't tow, race around, etc., and no other drivers except the two of us. This seems very usual, we had a 2015 Tahoe with the same engine/trans and never had a issue.

Well anyway, we are stuck now, miserable timing with the holiday weekend.

Tried to restart it today, no change. The engine revs a bit, although sounds like 1/2 the spark plug wires are missing.

On top of this, the dealer is 15 miles away and the route is on a 70mph highway, I can't drive it there!!

Any quick fixes, things to check?

2020 Owned 1 year

Engine 5.3

Trans 6 speed

Engine light is on

* Glad she didn't break down somewhere else!

Edited May 30, 2021 by DOUG75
details

Jac365 · May 30, 2021

Trouble codes??? If it sounds like "half the plug wires are missing" meaning skipping, rough running etc. sounds like it may have dropped a lifter or two. Several threads here pertain to this issue. More information needed though.

JimCost2014 · May 30, 2021

7 hours ago, DOUG75 said:

I haven't had any good luck for a while now. The wife went to town last night; about a 1 mile away and almost didn't make it back.

A 2020 Tahoe with 12,000 miles went into limp-mode at the bottom of the driveway, again, a short trip and the engine wasn't even hot.

Checked the oil, right where it should be, and it was changed a few months ago.

A few weeks ago we were at a dealer and said that we thought the transmission might be doing something strange and they test drove it with ultra soft care (like it hade a 20hp engine).

We don't tow, race around, etc., and no other drivers except the two of us. This seems very usual, we had a 2015 Tahoe with the same engine/trans and never had a issue.

Well anyway, we are stuck now, miserable timing with the holiday weekend.

Tried to restart it today, no change. The engine revs a bit, although sounds like 1/2 the spark plug wires are missing.

On top of this, the dealer is 15 miles away and the route is on a 70mph highway, I can't drive it there!!

Any quick fixes, things to check?

2020 Owned 1 year

Engine 5.3

Trans 6 speed

Engine light is on

* Glad she didn't break down somewhere else!

First thing, since it is still under warranty, don't drive it, call roadside assistance and have them come and put it on a flatbed, it is a free service.

Then let the dealership figure out what is wrong, another part of the bumper to bumper warranty.

DOUG75 · May 31, 2021

Thanks, we will be contacting them first thing Tuesday morning!!

Don't think it's a head/valve problem, tried staring it a few times, the engine sounds good for about 30 seconds then goes back into Limp-Mode.

I'll let you all know what happens next.

DOUG75 · June 3, 2021

So as not leave this open, we did get the Tahoe back the next day. A wire shorted out on the inside the wire harness and the fuse blew. They said the right side of the engine was dead and only running on the opposing four cylinders.

Well good news I guess, they spiced the wire and it runs fine again.

DOUG75 · June 4, 2021

"A few weeks ago we were at a dealer and said that we thought the transmission might be doing something strange and they test drove it with ultra soft care (like it hade a 20hp engine)."

Pfft took this Tahoe out today, it never ran better. I remember it sounded a bit strange @ WOT, but not now!!

The wire must have been sparking long ago, probably getting better gas mileage also.

Maybe my luck is changing (o;