Jump to content

Factory Rev-limiters

Thumper

Recommended Posts

Thumper Enthusiast

Thumper

Posted
Posted

Title and description pretty much says it all.

 

I just took my 2002 2500 Avalanche in for some warranty work since it runs rough on acceleration and fuel mileage is real bad (7).. I romped on it and when it got up to 4500 RPM is started really choking and puking until about 4700 and then it reved freely to 5200. Mind you, I rarely romp on this truck but I could not even outrun a newer Isuzu Trooper on a freeway on-ramp! (2 lanes narrowing to one about 1/8 mile away).. Guys - that Isuzu about kicked my butt!!! If anything I got the jump on him from the red-light!

 

Something is wrong with this truck. The service writer at the shop just called and told me that the rev limiter on that truck is 4,000 RPM and it will not go any faster than that. Seems odd that I was able to get it to 5200 if that was the case...

 

Does anyone know what the factory rev limiter is set at for this engine and the 6.0 as well? I am just about ready to trade her in on a Crew-Cab 6.0 if this is the way this truck is gonna be.

 

Thanks!

AZ1500 Enthusiast

AZ1500

Posted
Posted

The dealer is stroking you. If the rev limiter was set at 4000 rpm, the engine would never be able to produce it's max rated hp. Go to the service manager and/or the general manager and don't let up until they find the problem. :)

496Cubes Enthusiast

496Cubes

Posted
Posted

The 8.1's rev limiter is set at 5,000 RPM. The rev limiters are not only for neutral or park, it's all the time. I would guess the 6.0 is at least 5,000 or higher.

tmf6902 Senior Enthusiast

tmf6902

Posted
Posted

Yeah I know I have had mine well above 4k many times.....I havn't really watched the shift, when WOT, but I am pretty sure the needle goes all the way before it shifts.

Thumper Enthusiast

Thumper

Posted
  • Author
Posted
The dealer is stroking you.  If the rev limiter was set at 4000 rpm, the engine would never be able to produce it's max rated hp.  Go to the service manager and/or the general manager and don't let up until they find the problem. :smash:

I am a wrench myself (30+ years) but I typically don't like to work on my own stuff when it is in warranty..

The service manager told me that they found the problem. Apparently the programming in the ECM was not picking up the crank trigger therefore the timing was off.

 

Yup - more smoke. If the ECM could not pickup the crank trigger, the engine would not even run because it has no distributor!

 

I had a talk with the owner of the dealership and asked him to have the shop re-flash the ECM with all the latest updates from GM. He did. I will try the truck again and see what's going on.

 

One of the other issues I had was the plastic ring that encases the rear window has broken (shrunk) in two spots. This lets in water when I wash the truck. The rest of the water leaks in through the gasket at the base of the mid-gate and soaks the carpet. He (Service mgr) says that they will have to remove the midgate when the new window comes in anyways so he will wait until then to fix the mid-gate leak. Evidently the new window requires a new type of seal on the mid-gate.

 

BTW - losing a drag race to an Isuzu Trooper when you are driving (at the time) Chevrolet's most powerful truck, really SUX!!!

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • DustMcGrath
      Transmission Temperature Hitting 220s

      By DustMcGrath · Posted

      First of all sorry, I know there are a ton of transmission temperature threads...   My truck is a 2025 LZ0 High (10l89 10-speed) High Country with NHT max trailering package. The NHT package is supposed to have "enhanced cooling."   Normally the trans temp sits around 200. It seems like with any real stress it quickly jumps into the 220s (for example climbing a grade unloaded at lower speeds). I haven't towed much with this truck, but I'm concerned if it gets this hot unloaded.    I've tried a few different things to keep the temps down (tow/haul mode, sport mode, low range when that makes sense) and nothing seems to affect it.    I'm curious if others are the same behavior or if anyone has found techniques to keep the temps down. It seems like it just can't handle reduced airflow at lower speeds, even with relatively light loading.    Thanks!      
    • cautious optimist
      2027 3.0 l Duramax

      By cautious optimist · Posted

      I'm at 105,000 miles on my baby Duramax. No issues yet. I hit 31 mpg's traveling through hilly terrain to a project in Colorado. I will buy another 3.0. I'm not concerned.
    • cautious optimist
      Which 2027 engine will you choose?

      By cautious optimist · Posted

      I'm glad you have 14,000 trouble free miles. Frankly though, that's a really low bar. A bare minimum of 80,000 trouble free miles as the norm (rare exceptions always exist) across the whole model year should be a starting point. Good maintenance habits should push these past the 100,000 mile mark with only the most minor of issues. Let's hope GM truly leveled up the quality game with these new engines and exploding engines under 50,000 miles are gone. 
    • Atlas
      Slate Electric Truck

      By Atlas · Posted

      This is exactly the reason our EV has consumed so much of my driving. I don't want to fire up a cold diesel or gas engine just to drive 2 miles up to the store. It's arguably terrible for an engine. If I'm not driving at least 10 miles and don't need to do truck things, the truck stays parked.   Enter the EV. It's immediately heating or cooling the cabin as needed (heat pump). An engine doesn't need to warm up or be driven gently. I can tear off in it with ZERO guilt. Move the car 1/4 mile from store to store and not think "gee, I'm short-cycling a lukewarm engine".   It doesn't idle in a drive-through. Doesn't idle at stop lights. (OK, neither would the diesel, if I let stop-start have its way, but I don't).   Even moving it out of the garage to wash it... HA! It doesn't need to be started just to move 40 feet. I have cars that I will actually put in neutral and push (no start) in/out of the garage or shop if they absolutely HAVE to be moved. My nice Camaros.
    • ducky911
      side view camera

      By ducky911 · Posted

      Some trailer plugs don't work. This one worked for me. Been using it for two years no issues. Amazon.com: Reese Trailer Plug Adapter, 7-Way Male Plug to 7-Way Female Plug, LED Lamp Out By-Pass, Plastic, Black, Each : Automotive

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...