| Subject: | Roar from Engine Area On Cold Starts |
| Models: | 2007-2009 Chevrolet Colorado |
| 2008-2009 Chevrolet Trailblazer models |
| 2008-2009 GMC Envoy models |
| - Applies to any model listed above equipped with any one of the following engine RPO codes... LL8 (I6), LS2 (6.0 V8), LH6 (5.3 V8) LLV (2.9 I4) and LLR (3.7 I5) |
This PI was superceded to include 2008 model year. Please discard PIT4528.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may comment of a roaring type noise from the engine compartment. This typically will occur on cold starts and goes away as the engine reaches normal operating temperatures. This is the result of a new bi-metallic cooling fan that is used
on the engines and models listed above.
Recommendation/Instructions:
Fan roar is normal during cold engine start-up and should go away as the engine reaches normal operating temperature. No repair attempts should be made. This information is available in the customer's owners manual in section 5, "Service and Appearance
Care", "Cooling System".
2007-2008 Chevrolet Colorado, GMC Canyon and Hummer H3. Service Information owners manuals select - Service and Appearance Care - Checking Things Under the Hood - Description and Operation - Engine Fan Noise - Document 835016.
2008 Chevrolet Trailblazer, GMC Envoy and Saab 97x. Service Information owners manuals select - Service and Appearance Care - Checking Things Under the Hood - Description and Operation - Engine Fan Noise - Document 1490779.
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.
