hurst2001

Ok just a update : I had my p0304 code keeps coming back when the car is cold at start up, so i cleaned my throttle body put a new new plug and coil on cylinder 4 and still comes back ...Well then tried a trick at the tail pipe with a dollar bill and it does push it strong i know if it sucks it in theirs a problem ..tail pipe has carbon build up ,also had injection cleaner too and still know help.. Well took it to my mechanic friend and had a compression test done cylinder 1-3 were 150 and 4 was 140 ... Ok the motor is getting a little tired and we omh out the injector on cylinder 4 and it matches with the rest.. So i was thinking of run some carbon cleaner thru the intake some how and if that does not help,then i think the exhaust valve is burnt ..also check the plug on cylinder 4 no oil on it but had carbon built on it outside of the ring of the plug and electrode looked tan and a little white ... So if i can run some cleaner thur the intake is there a vacuum line were it will suck in while running? Sorry for the long post

firemangeorge

With #4 compression being that close to the other cylinders, I wouldn't be thinking a burnt valve.

And fwiw. The dollar bill test may have worked back in the day but on todays modern engines/exhaust system setups, it is not a reliable test.

Lucky

Did your replace the injectors? If not I would swap injector #4 with #1 and see if the problem moves to that cyl.

If you have already done that I would think you may have a carbon build up problem causing a misfire.

donbrew

I just poured Sea Foam into the PCV hose, following the instructions from Sea Foam for the introduction phase. Then let it sit overnight to do the "start up and spirited drive" portion. I did it twice put some in the oil some in the tank, that seems to have fixed the oil burning problem I had. My theory was a stuck oil control ring, thus the overnight soak.

Don't go all cowboy and dip the hose into a tub of the stuff, you will be sorry you did.

hurst2001

yes i had switch them and same problem so i ruled out injectors ..Ok last question were do you feed the sea-foam at ? thru the throttle body or were ? thanks again

Lucky

Here is a tsb that may give you some more info on carbon build up and misfires.

#PIP5029B: Engine Misfires Due To Major Carbon Deposits On The Intake And Or Exhaust Valves - (Sep 24, 2012)

Subject:

Engine Misfires Due To Major Carbon Deposits On The Intake And Or Exhaust Valves

Models:

2009 - 2013 Buick Enclave
2009 - 2013 Buick Lacrosse
2008 - 2013 Cadillac CTS, STS
2010 - 2013 Cadillac SRX
2013 Cadillac ATS, XTS
2008 - 2010 Chevrolet Cobalt SS, HHR SS
2009 - 2013 Chevrolet Traverse
2010 - 2013 Chevrolet Camaro, Equinox
2012 - 2013 Chevrolet Impala
2009 - 2013 GMC Acadia
2010 - 2013 GMC Terrain
2007 - 2010 Pontiac Solstice GXP
2009 - 2010 Saturn Outlook
2007 - 2010 Saturn Sky Redline

With any of the Following Direct Injected Gasoline Engines:

2.0 (RPO LNF)
2.4L (RPO LAF, LEA, or LUK)
2.8L (RPO LAU)
3.0L (RPO LF1 or LFW)
3.6L (RPO LFX or LLT)
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
This PI was superseded to update photo and part numbers. Please discard PIP5029A.
--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern


Some customers may complain of a MIL and engine misfire. In some cases, the misfire may be more apparent on a cold start, may count on a single cylinder or several cylinders, and may or may not be felt by the driver. Upon inspection, the technician will find one or more misfire codes (DTC P0300-P0306) stored in the ECM and SI diagnosis may or may not isolate the cause of the misfire depending on whether the intake/exhaust valves are sticking at the time of the diagnosis.

This may be the result of major carbon build up on the intake and/or exhaust valves as shown below so the misfires should not have appeared until at least 5,000 miles or more.













Recommendation/Instructions


If this concern is encountered, perform SI diagnosis. If SI diagnosis isolates a valve sealing concern and/or eliminates everything else external to the engine, decarbon the engine with Upper Engine and Fuel Injector Cleaner by following the guidelines below:
Important: Extreme care must be taken not to hydro lock the engine when inducing the cleaner, especially if it is induced without Kent Moore Tool # J-45076 / J-35800-A or equivalent. If too much cleaner is induced at too low of a RPM, or if you force the engine to stall by inducing too much cleaner at once, the engine may hydro lock and bend a connecting rod(s).





1. In a well-ventilated area with the engine at operating temperature, slowly/carefully induce a bottle of GM Upper Engine and Fuel Injection Cleaner into the engine with RPM off of idle enough to prevent the engine from stalling (typically around 2,000 RPM or so). Depending on the engine configuration, induce the cleaner through the throttle body or an engine vacuum hose/pipe. For best results, it is suggested to induce the cleaner through the throttle body with Kent Moore Tool # J-45076 / J-35800-A or equivalent (shown below).

2. Turn the engine off after inducing the cleaner and allow the cleaner to soak with the engine off for 2.5 to 3 hours (Do not let cleaner soak for more than 3 hours as remaining deposits may start to harden back up again).

3. Add a bottle of GM Fuel System Treatment Plus to the fuel tank and fill the vehicle with one of the Top Tier gasolines listed at http://www.toptiergas.com and/or in the latest version of 04-06-04-047 (USA) or 05-06-04-022 (Canada). See Bulletin 05-00-89-078 for more details on GM Fuel System Treatment Plus.

4. Test drive the vehicle extensively to circulate the GM Fuel System Treatment Plus.

5. Re-evaluate the concern to determine if it is repaired or improved at all. If the concern is improved but not repaired, it may be necessary to perform the above decarboning process a 2nd time.

6. To complete the repairs, advise the customer to only use one of the Top Tier Gasolines listed at http://www.toptiergas.com and/or in the latest version of 04-06-04-047 (USA) or 05-06-04-022 (Canada) to minimize future deposits. It can also be recommended to add a bottle of GM Fuel System Treatment Plus at every oil change as mentioned in the latest version of 04-06-04-051.


Kent Moore Tool Kit # J-45076
1. Pressurized Canister from J-45076 is shown - J-35800-A is similar

2. Throttle Body Cleaning Adapters J-45076-46 and J-45076-55 Shown (Equivalent Adapters Acceptable)

Notice: J-45076 was originally released to Cadillac dealers for decarboning Northstar engines but it has since been discontinued. This kit came with the pressurized canister and throttle body cleaning adapters shown above. As mentioned above, the J-35800-A is another pressurized canister that can be used. It was originally released in the 1990s for cleaning fuel injectors on the 4.3L, 5.0L, and 5.7L truck engines. If these tools are not available, it is also acceptable to use equivalent tools to perform this decarboning procedure.

Parts Information

Upper Engine and Fuel Injector Cleaner
1 - 88861013 Fuel System Treatment Plus

P0301 P0302 P0303 P0304 P0305

Lucky

I moved these posts into its own thread under problems/repair so it may help someone find it in the future.

hurst2001

thanks lucky you are very informative on the subject

Oldblue

let us know the outcome of this, Hurst2001.

hurst2001

yes i am still working on it but temps have been cold ..just a question were would you feed the seafoam at ? I want to feed it thur the intake to clean the valves ,i know the throttle body but want to go threw a vacuum hose ...Thanks