For 1990-2009 cars

# Crank No Start When Cold Due To Compression Loss - keywords cylinder cylinderhead extended hard head lifter loss

Subject: | Crank No Start when Cold due to Compression Loss

Models: | 2000-2007 All Passenger Cars with Gasoline Engines

| 2000-2007 All Light Duty Trucks with Gasoline Engines

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

### Condition/Concern:

Crank no start when cold. The engine may crank over very fast, as if there is low/no compression. It may also 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 due to fuel contamination. 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 will normally 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 lead 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 bulletin # 05-00-89-078A, 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 hydro-lock.
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 04-06-04-047F (U.S.) or 05-06-04-022B (Canada) for details regarding Top Tier Detergent Gasolines.

Note: If the condition is not eliminated chemically, it may be necessary to remove the valves to manually clean the stems.

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.