Engine Rattle - Help!

try2k · #1 (**permalink**) 11-07-09, 08:42 AM

I have a 2006 STS-V with relatively low miles (27k) and have suddenly developed a rather loud rattle in the engine. It happened after rapid accelleration upon passing a couple of cars yesterday. I didn't notice it until I was back in town traffic. It occurs only when I release the gas pedal to decelerate. It is quite noticeable upon slight accelleration, such as in traffic, when closing a gap and then releasing the throttle, to coast a ways. Also when pulling away from a stoplight and decellerating after reaching cruise speed. I have tried to duplicate it in the garage and I can still hear something, but it doesn;t seem to be as noticeable as it is when under the load. It almost sounds like valve train noise. Has there been any complaints of such a problem that I have missed on the forum, and if so, what was the ultimate diagnosis. I can't take the car in until Monday, and I would love to give them a direction to take, since they are not all that familiar with the V's here at my dealership. I get the feeling that they 'EARN WHILE THEY LEARN' on mine. Any help would be greatly appreciated. Thanks.

Indyblue98 · #2 (**permalink**) 11-07-09, 11:33 PM

On my 2007 there was noise that sounded like the bearings gone bad in the power steering or alternator. Turned out it was the catalytic convertor

I didn't believe it but 3 weeks later when the parts arrived & installed ,the noise was gone. The car had about 30K at the time. I made a post at the time and a few others had already been thru it. Hope your that lucky.

LITTLEELVISDAN · #3 (**permalink**) 11-08-09, 12:34 AM

Ask if they have a certified V tech in house. They should have at least one that was trained if its a Caddy dealer. If not call around to other Caddy dealers.

try2k · #4 (**permalink**) 11-08-09, 04:31 PM

Thanks Indyblue98. I sure hope it is something as simple as that. I would be so happy if they did not have to disassemble the motor, I did talk to a cadillac Tsch (Not certified V) and he thought it might be a lifter.

try2k · #5 (**permalink**) 11-08-09, 04:34 PM

Littleelvisdan: I doubt that they have a certified V technician here. Until a couple of months ago this dealership was strictly Chevrolet, but they bought out the Cadillac franchise and became the only Cad dealer in town. There is a Caddy dealer 50 miles north and another 40 miles south, so I will ask tomorrow when I take it in. Thanks.

LITTLEELVISDAN · #6 (**permalink**) 11-08-09, 04:47 PM

eek!!! i WOULD BE VERY WARY OF A CHEVY DEALER!!! mine was running hot one day so i drove it right into a big chevy dealer in the area. The techs and senior techs looked at it and laughed. They were never trained on a supercharged motor and wouldn't touch it.. Its worth your time and drive to take it to a proper Caddy dealer. Hell, most Caddy dealers have trouble with our cars, I would NEVER, EVER take it to a chevy dealer.......

LITTLEELVISDAN · #7 (**permalink**) 11-08-09, 04:54 PM

Addition>. I would let chevy change breaks, tires, oil. BUT and engine rattle or rattle anywhere around that engine HELL NO. They think its a Vette engine in there and it is FAR from it. Especially if they say lifter already. That tells me they don't have a clue about a North Star motor and you should run.