When I bought my GV from the dealer, I noticed some weird knocking noise coming from the engine. I spoke with the Suzuki dealer service department, and they told me that it is the fuel injector doing its job and all is normal.
A year later and 22K miles, the knocking was getting worse and I was getting worry too. I took my GV again to the same dealer, and met another service manager who was very knowledgeable. He knew what the problem was and showed me the service bulletin. Moreover, he got me out of there in 25 minutes without any more knocking noise!! Sweet
Problem: Engine knocks at idle when fully wormed up.
Problem area: Drive belt tension change.
Model year affected: ALL Grand Vitara 2006 to 2008.
Affected Vin(s): Vehicles up to production date of July, 9 2007.
Condition: After the engine completely worms up, a knocking noise can be heard from the bottom of the engine.
Cause: Mis-adjusted drive belt tension will cause the engine crank shaft to be abnormally oscillate which can produce an audible knock sound similar to excessive bearing clearance noise (bottom end knock.
Failed part number: 17521-66J00.
Complaint Code: 84.
Defect Code: 48.
Correction: Suzuki has issued a technical bulletin (TSB NO. TS 22 09197). Please take your GV to the nearest Suzuki dealer for defect code # 48, or mention the bulletin number above.
The dealer will adjust the belt tension, or replace your the tension belt with new one and apply correct adjustment.
Time to correct issue: 10-30 minutes (while you wait).
Cost to you: ZERO $$$ /$$$$ NONE / $$$$00000000000000000
Dealer will try to tell you any bullsh*t: Call Suzuki.
This issue is covered under warranty and dealer should use authorization code # 48 to bill Suzuki for all work done in regards to this issue.
What if your vehicle is over 36k miles and 36 months? Repair still apply without any cost to you. Suzuki sent those cars on the road knowing they have faulty tension belt adjustment.
Snapfish