4/17/2019 #PIP3146D: Rough Idle Crank No Start Extended Crank Or Misfire When Cold Due To Sticking Valves Or Excessive Carbon On Top Of T…

Report a problem with this article Rough Idle Crank No Start Extended Crank Or Misfire When Cold Due To Sticking Valves or Subject: excessive carbon on top of the valves

2000-2012 All Passenger Cars with Gasoline Engines Models: 2000-2012 All Light Duty Trucks with Gasoline Engines

This PI was superseded to update recommended field, model years and engine list. Please discard PIP3146C.

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

Condition/Concern: Rough idle, misfires, extended crank, or crank no start when cold. The engine may run rough for up to 5 minutes after starting the engine and may exhibit a P0300 DTC too. This may be caused by sticking valves or excess carbon due to fuel contamination

Note: fuel oxidation and volatility concerns can often cause these issues as well, however they cannot generally be checked in service. Trying a different, high quality fuel is sometimes the best diagnostic.

When the engine is cold, the compression on multiple cylinders may be at 0 PSI. The engine also may pop through the intake or exhaust while cranking and the spark plugs may be fuel fouled when inspected. Some engines may also experience valve damage or cam followers that are out of position as a result of this.

This condition can occur in specific areas of the country for a period of time and then it will no longer occur after the suspect fuel source has been consumed in that area of the country.

Recommendation/Instructions: If the SI Diagnosis leads to a compression loss due to sticking valves, the following information may help:

If there is no sign of valve damage or cam followers that are out of place, perform the following procedure to free up sticking valves and to prevent the valves from sticking again. If valve damage is present or if there are cam followers that are out of place, perform engine mechanical repairs as necessary to correct the concern and then perform the procedure below to prevent the valves from sticking again.

1. Clean the fuel system by following the applicable "Fuel System Cleaning" procedure outlined in SI. 2. Add fuel injector cleaner "GM Fuel System Treatment PLUS, P/N 88861011 (for U.S. ACDelco, use 88861013) (in Canada, 88861012)"... see This PI was superseded to update recommended field, model years and engine list. Please discard PIP3146C. bulletin # 05-00-89-078B, to the fuel tank in the approved quantities. 3. Refill the fuel tank using fuel from a high volume, high quality filling station. 4. Clean the induction system using GM Top Engine Cleaner. Follow the directions on the can but DO NOT force the engine to stall since forcing the engine to stall with liquid Top Engine Cleaner could cause the engine to https://www.motologic.com/car/32f9e7b0-176f-012e-32ba-19005f6e69db/article/5f9dd390578676498085f789209ed0a1?returnPath=%2Fcar%2F32f9e… 1/2 4/17/2019 #PIP3146D: Rough Idle Crank No Start Extended Crank Or Misfire When Cold Due To Sticking Valves Or Excessive Carbon On Top Of T… hydro-lock. * If available use an atomizer with Top Engine Cleaner through the throttle body. 5. Advise the customer to change fuel filling stations. They should use fuel from only high volume, high quality filling stations or they should use a Top Tier Detergent Gasoline if available. See 04-06-04-047I (U.S.) or 05-06- 04-022G (Canada) for details regarding Top Tier Detergent Gasolines. ADDITIONAL SI KEYWORDS:

None

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

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 WE SUPPORT vehicles, or to provide information that could assist in the proper service of a vehicle. VOLUNTARY Properly trained technicians have the equipment, tools, safety instructions, and know-how TECHNICIAN to do a job properly and safely. If a condition is described, DO NOT assume that the CERTIFICATION 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.

https://www.motologic.com/car/32f9e7b0-176f-012e-32ba-19005f6e69db/article/5f9dd390578676498085f789209ed0a1?returnPath=%2Fcar%2F32f9e… 2/2