GM What's the deal with your engines?

[sumo]

i complained about the oil consumption. It was a pain. In the end i was able to get the dealer to do a decarbon of the engine, Replace valve covers and install a shield in the lower part of the engine that surrounds the active fuel management solenoid.

 

[llllljrlllll]

i complained about the oil consumption. It was a pain. In the end i was able to get the dealer to do a decarbon of the engine, Replace valve covers and install a shield in the lower part of the engine that surrounds the active fuel management solenoid.

What does the shield do in this case? Decarbon the engine? What does this
for the active fuel management?

---------- Post added at 01:00 AM ---------- Previous post was Yesterday at 11:15 PM ----------

So I found this thread, this is the same exact thing that happened to me, with the cylinder 1 failure http://www.tahoeyukonforum.com/forum/showthread.php?t=50089. Read up on it, it will enlighten your mind....Keep Hoeing

---------- Post added at 01:35 AM ---------- Previous post was at 01:00 AM ----------

So I have found out upon reading all the threads that it's the active fuel management system that ruined my engine, if you read this, try to get bb to turn off the afm of your hoe, before the same thing happens to you. http://www.tahoeyukonforum.com/forum/showthread.php?t=43966

---------- Post added at 01:43 AM ---------- Previous post was at 01:35 AM ----------

And another on Sumos thread http://www.tahoeyukonforum.com/forum/showthread.php?t=44321&page=5

---------- Post added at 01:54 AM ---------- Previous post was at 01:43 AM ----------

And another, same issue, different description http://www.tahoeyukonforum.com/forum/showthread.php?t=44689

---------- Post added at 02:28 AM ---------- Previous post was at 01:54 AM ----------

another one http://www.tahoeyukonforum.com/forum/showthread.php?t=28322

 

[llllljrlllll]

Interesting to know that just by switching over to engines and tranny and all traffic for this thread stops.

 

[sumo]

What does the shield do in this case? Decarbon the engine? What does this
for the active fuel management?

---------- Post added at 01:00 AM ---------- Previous post was Yesterday at 11:15 PM ----------

So I found this thread, this is the same exact thing that happened to me, with the cylinder 1 failure http://www.tahoeyukonforum.com/forum/showthread.php?t=50089. Read up on it, it will enlighten your mind....Keep Hoeing

---------- Post added at 01:35 AM ---------- Previous post was at 01:00 AM ----------

So I have found out upon reading all the threads that it's the active fuel management system that ruined my engine, if you read this, try to get bb to turn off the afm of your hoe, before the same thing happens to you. http://www.tahoeyukonforum.com/forum/showthread.php?t=43966

---------- Post added at 01:43 AM ---------- Previous post was at 01:35 AM ----------

And another on Sumos thread http://www.tahoeyukonforum.com/forum/showthread.php?t=44321&page=5

---------- Post added at 01:54 AM ---------- Previous post was at 01:43 AM ----------

And another, same issue, different description http://www.tahoeyukonforum.com/forum/showthread.php?t=44689

---------- Post added at 02:28 AM ---------- Previous post was at 01:54 AM ----------

another one http://www.tahoeyukonforum.com/forum/showthread.php?t=28322

Its like a chemical tune up. They let it a fluid sit in the engine for some time and what it supposed to do is breakup the carbon deposits that form on the valves, on the pistons and in the intake. they say if carbon forms around the valves, it can prevent the valves from fully closing causing oil to sneak by and get burned up. The shield in around the afm solenoid is to prevent oil spalshing past a certian point and getting burned up. Theres a bulletin that explains that but i have to hunt for it.



Here it is

If it doesn't correct oil consumption issue they must replace piston and rings! WOW

#10-06-01-008B: Engine Oil Consumption on Aluminum Block Engines with Active Fuel Man
xTooltipElement
Service Information
2009 Pontiac G8 | G8 Service Manual | Bulletins By Category | Technical | Document ID: 2596962
--------------------------------------------------------------------------------

#10-06-01-008B: Engine Oil Consumption on Aluminum Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder) - (Mar 7, 2011)


Subject: Engine Oil Consumption on Aluminum Block Engines with Active Fuel Management (AFM) (Install AFM Oil Deflector and Clean Carbon from Cylinder)


Models: 2007-2009 Cadillac Escalade, Escalade ESV, Escalade EXT

2007-2009 Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe

2007-2009 GMC Sierra 1500, Sierra Denali, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL

2008-2009 Pontiac G8 GT

Equipped with Aluminum Block V8 Engine with Active Fuel Management (AFM) (RPOs LC9, LH6, L76, LFA, L92)

with Greater than 45,000 km (28,000 mi)




--------------------------------------------------------------------------------

This bulletin is being revised to add the 2009 model year and new Correction information for the 2009 model year - left rocker arm cover replacement. Information has also been added after step 9. Please discard Corporate Bulletin Number 10-06-01-008A (Section 06 - Engine/Propulsion System).


--------------------------------------------------------------------------------

Condition
Some customers may comment about engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi). Verify that the induction system is assembled correctly and that there is no evidence that the engine has been ingesting dirty air due to a mis-assembled induction system. Also verify that the PCV system is functioning properly. If diagnostic procedures indicate that oil consumption is piston/piston ring related, verify that oil consumption is less than 3,000 km (2,000 mi) per liter/quart. If these conditions are met and oil consumption is less than 3,000 km (2,000 mi) per liter/quart, perform the service indicated in this bulletin.

Cause
This condition may be caused by oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not cause a problem. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption.

Correction
2009 Vehicles Only
Important: This left rocker arm cover is NOT to be used on 2007-2008 vehicles because of the calibration of the PCV orifice being different in 2007-2008.

A new left rocker arm cover has been released for 2009 engines. Technicians should replace the left rocker arm cover with GM P/N 12642655. This rocker arm cover has relocated PCV drain holes that prevents PCV pullover into the intake manifold. Refer to SI for Valve Rocker Arm Cover Replacement - Left Side.

2008-2007 Vehicles Only


To correct this condition, perform the piston cleaning procedure as described in this document, and install a shield over the AFM pressure relief valve per the procedure outlined in this document. Monitor oil consumption after this repair to ensure oil consumption has improved to acceptable levels. If this repair does not correct the condition, it may be necessary to replace the piston assemblies (piston and rings) with new parts.

Important: It is critical in this cleaning process that the engine/fuel injector cleaner remain in the cylinders for a minimum of 2.5 hours to fully clean the components. The cleaner solution must be removed before a maximum of three hours.

Verify the oil consumption concern following Corporate Bulletin Number 01-06-01-011F. If oil consumption is found, continue on with this bulletin.
Remove the spark plugs and ensure that none of the pistons are at top dead center (TDC).
Clean the pistons by putting 118-147 ml (4-5 oz) of Upper Engine and Fuel Injector Cleaner, GM P/N 88861802 (in Canada, use 88861804), in each cylinder. Allow the material to soak for at least 2.5-3.0 hours, but no more than three hours and then remove the cleaner. A suggested method of removing the cleaner is cranking engine over. Make sure to unplug the ignition coils and fuel injector before cranking the engine over. Also make sure that the painted surfaces are covered so no damage is done.
Remove the oil pan. Refer to Oil Pan Replacement in SI.



Remove the AFM valve (1).



Install the new shield (1), GM P/N 12639759, and tighten the AFM valve to the oil pan to 28 N·m (20 lb ft).
Important: Ensure that the engine cleaner is thoroughly removed before reinstalling the spark plugs. Failure to do so may result in a hydro-lock condition.

Reinstall the spark plugs. Replace the spark plugs if necessary due to full of carbon. Refer to the parts catalog.
Reinstall the oil pan. Refer to the Oil Pan Installation procedure in SI. Replace the oil pan gasket if necessary. Refer to the parts catalog. Replace the engine oil if necessary.
Re-evaluate the oil consumption. Document on the repair order. If the oil consumption is still greater than 0.946 L (1 qt) in 3,200 km (2000 mi), replacement of the pistons and rings will be required.







Important: Some minor scratches may be noticed on the cylinder walls during piston and ring replacement. If the scratch cannot be felt when running your finger nail over it, the scratch is considered normal wear and the block or engine should not be replaced.

Parts Information
Part Number
Description
Qty

12639759
DEFLECTOR-OIL PRESS RLF VLV (quantity of 3 per order) (07-08 Models Only)
1

88861802 (in Canada, use 88861804)
CLEANER, F/INJR 16 OZ LIQUID POUR (Upper Engine and Fuel Injector Cleaner) (07-08 Models Only)
3

12642655
COVER ASM-VLV RKR ARM (09 Models Only)
1


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

J7555*
Install AFM Oil Deflector and Clean Carbon from Cylinder
3.5 hrs

Install AFM Oil Deflector and Clean Carbon from Cylinder (4WD)
4.5 hrs

Install AFM Oil Deflector and Clean Carbon from Cylinder (G8 Only)
10.5 hrs

J7561
Rocker Arm Cover- Left Bank - Replace- (For 2009 Only)
0.6 hr

*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© 2011 General Motors. All rights reserved.

 

[llllljrlllll]

Wow, I complained to my service tech about the oil consumption before my 100k mark, I had it in to replace a motor mount. And of course he said that it was normal for it to happen. In my case, I do a lot of driving in my truck, I work about 30 miles from home, and with LA traffic I'm siting in traffic from 1hr to 1 1/2. And I used to go to Vegas a lot. So my truck has a lot of highway miles which would explain the failure in my piston. This TB just pisses me off. This could of been prevented if he would of looked at his terminal for any TB.

 

[GM Customer Service]

I bought my truck brand new in 2007, and I've never had such a bad experience with buying a new vehicle. I thought that GM Trucks were reliable and strong vehicles. That as long as I maintained it, oil change, good gas, tune up, that this engine would last me past the 200k mark...I would never had thought that at 138k the engine would throw me a curve. I've had the same problem as everybody else, with oil consumption on this engine and GM saying that it is normal for oil to burn on this engines, Specially since I've just found out that my LS has a 5.3 engine so I figured it's normal. I've also read somewhere online that GM while building this engines they didn't align the rings how they needed to be on the piston causing that famous burning oil. Which would make sense, oil slipping through rings= burning oil. But can anybody explain to me why at 138k I need to have my Tahoes engine rebuilt. I was driving to work, when my engine started sputtering and knocking, stabilitrak off, CEL ON, hooked up my machine to it and it gave me P0301, I took it to the mechanic, misfire on cylinder 1. Mechanic checked my spark plugs, wires, coils, everything OK, still the knock, then he hooked up the compression machine to check compression on the engine, and guess what!!!! NO COMPRESSION, he explained to me that is very common for GM engines to have this problem, and unfortunately his diagnose for my Tahoe was to have the engine rebuilt. WHAT!!!!! $3k to have it done, GM can you explain to me why I have to rebuild and engine at 138k, I knew that at some point I would have to do that, but at 138k come on, your consumers buy your product thinking that they have a quality USA product, I've had quite a few problems with my trucks as some as you guys know, in case you didn't here are a couple of threads I've started. http://www.tahoeyukonforum.com/forum/showthread.php?t=21252 , http://www.tahoeyukonforum.com/forum/showthread.php?t=21570 but this is just BS, yes, I know in this case I turn to our GM people and asked them what can you guys do for me in this case. Should an engine need a rebuild after it has been taken care of. And at 138k, any help would appreciated it.

Hello,

I am sorry to hear that you are experiencing an issue with your vehicle's engine. I understand that you feel frustrated. I cannot guarantee anything but I would like to look into your concern. Please private message me.

Best regards,

Jennifer T.
GM Customer Care

 

[cparedes]

I had this oil consumption problem a year and half ago I only had 88k, problem turned out to be a bent lifter and a bunch of other major stuff, in short my whole engine was flooded with oil. Dealer quoted me $3k repairs, cuz I needed a engine & tranny rebuild. Tranny (stability track problem thing) But they talked to GM for me and GM reduce the quote which came out to $1800. The funny thing is, since I had all these problems with my Tahoe, I wouldnt trade it for anything else...

 

[Fast55]

Much of this became a problem when GM stopped sizing pistons to bores on an individual basis and started the "any piston fits in any bore" method of building engines. Within a specified range, any piston does in fact fit in any cylinder. Given that too tight of a final clearance is far worse than too loose, many engines will have one or more pistons that pretty much flop around in the bore. Worse still is that piston skirts have gotten shorter and ring tension lower in the name of fuel economy.

Do a search for "piston slap". No matter what they say, it is NOT a good thing to have a piston bang around in the bore, even if it you can only hear it when the motor is cold (typically goes away when warmed up). It's not just GM, and it's NOT just motors with AFM, not that it helps you fix your motor.

 

[GM Customer Service]

I had this oil consumption problem a year and half ago I only had 88k, problem turned out to be a bent lifter and a bunch of other major stuff, in short my whole engine was flooded with oil. Dealer quoted me $3k repairs, cuz I needed a engine & tranny rebuild. Tranny (stability track problem thing) But they talked to GM for me and GM reduce the quote which came out to $1800. The funny thing is, since I had all these problems with my Tahoe, I wouldnt trade it for anything else...

Hello cparedes,

I apologize for any trouble you have had with your vehicle. That is great to hear GM was able to help out with your situation. I am glad to hear despite of all the issues with your Tahoe, that you still love the vehicle! We can be reached via private message if any other concerns or questions arise in the near future. Continue to enjoy driving your Tahoe!

Sincerely,

Laura M.
GM Customer Care

 

[07Burb]

JR...I'm a little late to this but I had a VERY similar issue to yours just a few weeks back. My burb has 135k on it and I lost compression on cylinder #4. The issue was caused by a bad lifter and was a direct result of the crappy 4/8 cylinder mode crap. So I had them replace all the lifters on that side and now I've had that AFM tuned out so hopefully I'll be good going forward. If your shop is automatically jumping to needing the motor rebuilt I'd be questioning that!! It's most likely just a lifter that crapped out.