Hello and good morning. I have the 2004 Chevrolet Trailblazer LS model ( well-maintained) and it stutters between 55-65 mph only while accelerating; but I have replaced the coils and spark plugs and there is no check engine light. What do you think? Thanks for any help you can offer...Im grateful.
Nancy
When was the fuel filter last replaced?
not too long ago....that fuel filter was replaced.
I would check the fuel filter and also the fuel injectors. They could be clogged up or, depending on mileage, worn out.
Wouldn't hurt to run a bottle of STP injector cleaner through it at the next fill up to see if you notice a difference.
Then I would follow the other suggestions by @mod_man. You could also check the air filter and clean the throttle body and MAF sensor as well if those maintenance items have not been addressed recently. Hopefully it just needs a little TLC and there's not a bigger issue like the fuel pump starting to fail for example. Take care of the simple things first. Good luck.
You're definitely not alone. It may actually not be engine related, it may be your transmission creating the issue.
I googled the following: 2004 Chevrolet Trailblazer LS model stutters between 55-65 mph
Quite a few different sites came up:
https://www.trailvoy.com/threads/hesitation-at-highway-speeds.85198/
https://www.trailvoy.com/threads/chugging-stuttering-at-steady-speed.143290/
https://gmtnation.com/forums/threads/slight-hesitation-or-bucking-in-4th-gear.12273/
You might be on to something there.
The bad thing is that the threads really didn't provide any concrete solutions that solved the problem. I think only a dealer level scan tool that catches the problem in the act will be able to figure it out.
Sounds like the famous bad torque converter shudder for Chevy transmissions.
