Truck just revs after driving fine, code P0300

Tiny
SHAWN88
  • MEMBER
  • 2005 CHEVROLET TRAILBLAZER
  • 4.2L
  • V6
  • 4WD
  • AUTOMATIC
  • 180,000 MILES
I bought the vehicle listed above LT and it drove fine for about 40 minutes after buying it. Then I had to put it in reverse then back to drive and then it would just rev when I push the gas pedal. Now after it sat for a while I would try and start it again and see if it would move and it would start rolling again then start to rev again. I also got a code that is P0300, I don't know if that would be a problem for it to not drive like it should or what.
Tuesday, March 15th, 2022 AT 1:06 AM

26 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

I would start by changing the oil and filter in the transmission. The filter may be partially clogged, not allowing pressure to the valve body.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

https://www.2carpros.com/articles/automatic-transmission-problems

The 300 code is for the engine. It is a misfire code. I attached a guide for possible issues causing the code.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 1:39 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Thanks. I'll let you if it worked.
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 1:51 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You are welcome.

Always glad to help.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 1:54 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
I have one more question now. I have the vehicle listed above LT and also, I have a 2004 trailblazer LS the LS blew the rear differential out. Would I be able to use the rear differential off the LT for the LS?
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:00 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Yes, it will but you need to confirm the gears are the same ratio.

Remove the rear cover and check the numbers off the back of the pinion gear.

https://www.2carpros.com/articles/differential-service

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:08 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Okay, I will check it out I know the LS is G80 GU6 just have to check the LT. Thanks again.
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:10 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You are welcome.

Let us know if you have any other questions.

Always glad to help.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:13 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
So, both of the vehicles say G80 and GU6, so that means they are both 3.42 with the locking right?
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 3:30 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Did you remove the back cover and check the numbers on the back of the pinion as I suggested?

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 4:31 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Not yet, taking kids to school and when I get back, I'll do that.
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 4:38 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
We will be here for you.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 8:33 AM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Okay. Sorry, I got a little busy today. So, I took the transmission pan off to check and drain the fluid and there is silver all around in it and the magnet was covered to the max it seemed like. So, I'm assuming the transmission is going out or is bad, right?
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 12:47 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Correct.

You need either an overhaul or replacement. There is no easy fix when it is coming apart internally.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:11 PM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Yea, that's exactly what I was thinking myself. The guy I bought it from said he's willing to get another transmission for it and have it put in or he would buy one and I could put it in. I'm thinking I might have him either buy it and have it put in or just give me the money back.
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 2:56 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
If you are keeping this long-term, I would consider having it overhauled and done correctly. Let him contribute to that cost for you. That way, you have a warranty if there is a problem.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 4:16 PM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
I really appreciate the help you gave me. If I ever need help again, I will be sending it right on this site. Again, I really appreciate everything you have done.
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 4:28 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Thank you for the kind words.

We are always glad to help.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, March 15th, 2022 AT 4:36 PM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
https://www.replicarclub.com/how-to-reset-transmission-control-module-chevy/
Was this
answer
helpful?
Yes
No
Wednesday, March 16th, 2022 AT 2:34 PM
Tiny
SHAWN88
  • MEMBER
  • 15 POSTS
Does this actually work?
Was this
answer
helpful?
Yes
No
Wednesday, March 16th, 2022 AT 2:34 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You can try it but no, it only erases the memory for the shifting points and the modules will relearn the correct shift points.

It has no effect on your current issues.

Roy
Was this
answer
helpful?
Yes
No
Thursday, March 17th, 2022 AT 6:44 AM

Please login or register to post a reply.

Related P0300 Content

VIEW MORE