KNOCK SENSOR ISSUE ON BRAND NEW ENGINE 05 TAHOE

[KennyRob05]

I have an 05 Tahoe 4x4 LT that I recently installed a new Engine and Transmission from Frasers Engines & Transmission (With 3 yr No Fault Warranty). Once initial bugs were worked out with bad grounds, I got truck running and began driving around and its very under powered, burning through a ton of gas and I have tapping. I also keep getting knock sensor codes (P0327 & P0332). Im on my third set of knock sensors. Ive tried dealer parts, AC Delco and Dorman and all trip the same codes. Looking for yalls advice I've put approx 300 miles on new engine and want to make sure its not a lifter or internal issue before I reach back to Frasers for a new motor. Appreciate any feedback. Thanks guys

 

[Fless]

Carefully inspect the engine mounts and the transmission mount, as well as the tranny crossover bolts for tightness. If the block is moving around any the knock sensors could be picking that up.

 

[strutaeng]

Are you sure it's not actually detonating? It sounds like it could be based on your description (?) If it is, the next question is why? Maybe create a video on YT and then post the link here.

Was the engine the same type as your old one? Like, matched the RPO code?

 

[OR VietVet]

Welcome to the forum from Oregon.

Did you replace the engine yourself?

Recheck all your work and tensions and make a noise video and post here. Sounds like the "under powered" is because the existing knock sensors are doing their job. I would assume Fraser's Engines would want you to take to a qualified shop and have it diagnosed.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving clarifying questions and sage advice from the knowledgeable folks on this Forum.

 

[KennyRob05]

Carefully inspect the engine mounts and the transmission mount, as well as the tranny crossover bolts for tightness. If the block is moving around any the knock sensors could be picking that up.

Thanks for the advice. My brother suggested the same thing. I will double check mounts.

 

[KennyRob05]

Are you sure it's not actually detonating? It sounds like it could be based on your description (?) If it is, the next question is why? Maybe create a video on YT and then post the link here.

Was the engine the same type as your old one? Like, matched the RPO code?

Yep I ordered the exact same motor compatible with RPO codes. 5.3L. I was reading another thread about that as well. I agree with you. I’m thinking I’m will have to drop off for diagnostic thanks for advice

 

[rockola1971]

Compression check. Please tell me you didnt reuse plugs, wires, sensors and coils on a new block. Verify ALL engine wire harnesses are where they are suppose to be and not pinched between tranny and block and anywhere else possible during engine install and final assembly of bolt ons.