Service Bulletin: #07123A Engine Intake Valve Seat/Misfire

[xronx]

Disclaimer
The community here at 355nation.net urges you to please use caution and seek professional assistance when performing modifications to your vehicle. Before attempting any modification it is advised that you refer to your Colorado or Canyon service manual or contact a certified mechanic as not all GMT355 trucks are the same. The staff and the associated members are in no way responsible for any damages, injuries or other harm inflicted to your vehicle or yourself which may result in attempting these modifications. The posts and content presented on this site reflect in no way the views of 355nation.net or it’s ownership.




The Following is a GM direct letter to owners of the Colorado's and Canyon's listed years 04-06, both 4 cylinder 2.8L and 5 cylinder 3.5L trucks. Breakdown of specific Vin inclusion as follows.

Note: This condition may be diagnosed through several DIY methods.

(1) let the truck sit at idle for about 30min. if equipped with aux. and access. equipment such as A/C, systems, lights ect. Enable all. Observe trucks idle; a rough idle should lead to further diagnosis.

(2) A compression check can be used, though more invasive than a cylinder leak-down test. Either will work. Observe compression/pressurized cylinder for a decline in pressure within, be sure the cylinder is at TDC on the compression stroke as you are testing it.

***WARNING*** If you are not experienced in performing these tests bring you truck to a dealer, leave it to them. It is free as covered in attached Scans of the GM direct Recall, and letter to owner.



LETTER TO OWNER




RECALL INFORMATION







V.I.N. Locations are on various parts of our trucks. the simplest to find is underneath the glass, by the drivers side of the windshield; If difficult to read as it sometimes becomes, another copy of the VIN is on the inside of our drivers side doors. I believe a third is also in the Glove Compartment where our vehicle specific information is held.

[swamp_rat]

mine is starting to tick AGAIN. POS!

[Southbound Cenla]

Wut about isuzu!?!?!?

[BMFP]

Old thread but, does anyone know what the repair process is on this? Is it valve replacement or regrind or what?

[John D]

Originally Posted by BMFP

Old thread but, does anyone know what the repair process is on this? Is it valve replacement or regrind or what?

On my 2006 Canyon, 4 cyl., they replaced the whole head. I wasn't noticing much in the way of problems so I waited until I had 99,900 miles on it and took it in. They verified that it was affected and took care of it.

[FixxxerKH202]

I've got an 07' 3.7L that had 2 bad valve seats, they swapped the head and it took 3 days.

[pappawheely]

I just bought a used '04 engine and the dealer had no record of the repair. I wonder if it's good or not?

[05 bow tie]

i have about 82,xxx on mine and it worries me cause mines an 05 so its 6 years old no way i can afford it if it doesnt happen before hand any one know if there is a way to get ahold of gm to talk to someone

[rastok]

do you guys know it they could refuse to do the job if my first cat is gutted ??

[xronx]

i dont see any way they would know, and thats post valvetrain... dont say anything, if they question you, deny any knowledge of it...

also to know if you have the issue, they will perform and cylinder LEAK DOWN test, it's a fairly simple, not so invasive procedure, however they will charge diag time. if the issue is not present.

[rastok]

ok.. im 99% positive i have a bad head.. i have a jumping iddle every so ofen, a cel that go on and off, it's leaking oil from all over the head... im just scared to take it in and they dont find nothing and after im stuck with all my problem... i would like to make sure they will change everything before a take it in... question for you.. do i have to take it in while ther cel is on or it dosent mattter...

[xronx]

Doesn't matter if the cel is illuminated, if there was a cel there will be a memory (history) code.... also if its intermitten a possible Pending code... they will find the code if it is there, the leaking around the head could be multiple things... also if you have the "lobby" rough idle, take it in, at the worst it costs you a lil. bit of money. If you wait til you pass your warranty, you'll be kicking yourself.

I personally haven't looked into the issue on my own vehicle... i work on cars all day long, if it starts and drives, i could care less... for someone who isn't willing to spring out the full cost for repair out of pocket, or do it in their driveway... just take it in.

[rastok]

Ok, good info thanks alot, for info i have a 2006 with 67000 km on it and im not thé original owner of it. Seriously, im f***** scared. LOL

[05 bow tie]

mines gonna be cutting it close if it doesnt happen soon, but my question i bought mine used will they still do it and how can i get ahold of gm to work somethin out if somethin happens after the time limit

[brady]

I'm pretty sure that this is the problem I'm having...how do i take advantage of this recall...what do i say when i call the dealership?

[xronx]

This is simple. Whether you are first second or third owner, the warranty covers the vehicle, not the owner. Also if you are over the limit by even a mile, they can reject your claim for warranty work, hoever if you are in good standing and a regular customer, they do have some swing with GM, beyond that your looking at getting the service departments DIRECT number to GM to inquire upon after warranty work performed for warranty labor.

If you call up your local dealer, just explain to them you became aware of a TSB for intake valves on xxxx through xxxx year colorado's and they will ask for your vin, also they will tell you to schedule it in so they can perform the cylinder leak down test. Also they should tell you if no issue is present you will be charged the labor/diagnostic charges.

[parkerb]

I have a question for anyone that has had this done. I was going to bring mine in and have it done, already talked to my service advisor and he said he would check it out. The one thing I was worried about though is if they reflash the computer after replacing the head. I have a tune and don't want it wiped out.

[xronx]

I doubt they will, unless the vehicle calls for an update already, which is doubtful.. most likely they will reset the KAM so the sensors can relearn their values and strategies accordingly to adapt to the correcting factors, such as air flow, volume... ect.

[barman84]

Do you think they will void this claim if you have oversized tires?

[rastok]

how do the leak down test is done.. also could they say something is i have a gutted cat '' manifold '' and a flowmaster serie 44