Vibrating noise coming from engine while sitting at light. Stops if I hit the gas and hold the brake at the same time. I just had the engine/transmission mounts replaced and this did not solve the problem!
2005 Trailblazer: For the past 1 ½ years it has made a loud vibrating noise that no one has been able to identify. It is not a valve and apparently not the motor mounts. When I come to a stop and the engine is engaged, it loudly vibrates. When I put it in neutral or park, it quiets down. It seems worse if I am on even a slight incline. Neither our mechanic or the dealership have figured out what it is. The dealership would LOVE to figure it out by fixing everything that isn't broken first.
I experienced this problem. Had a dealership look at it several times and told me I was crazy. Basically, when sitting at idle while in drive the engine would rattle as if a rough idle. I started taking my vehicles to a smaller repair shop. They found that my Trailblazer was 25 computer updates behind and that after updating it corrected the problem.
Check engine light would come on for a while then go off. It finally stayed on all the time. The engine vibrates when idling in gear, but no vibration at all when I put it in park or neutral. The vibration was worse when the a/c was on. I replaced the a/c idler pully but still vibrates. No driving issues and rpms arent affected. Took it to autozone to let them diagnose it but they couldnt get a reading. I've had a few people tell me it could be the 02 sensors but I wanted to get more feedback before I try to replace it.
Found the problem!
I started having this problem last week. My 05 trailblazer would jump and stutter when I was idling. It got better when I put it in park or neutral but this only helped for a day. It got worse and the check engine light came on. I had a repair done and I was told that Chevy reported issues with the seal that keeps water out of the engine. We had a huge rain storm the day the issue started and the faulty seal allowed water to pool around the spark plugs. The fix (from Chevy) was to check spark plugs and coils for signs of water damage and if there was any they needed to be replaced. I had to have multiple spark plugs and coils replaced but this DID fix the problem. They also replaced the seal to prevent this from happening again.
With so many people having a similar issue I'm wondering if it is being caused by the same thing? If so I'd sure like to know how many people are affected and why Chevy isn't doing a recall for this problem.
Just replaced transmission motor mount and both engine mounts , had the throttle body cleaned and I still have a very bad vibration from the engine. My steering wheel shakes bad and you can feel it through the whole truck. Sometime my idle drops then revs up. I have taken it to a mechanic several times and they tell me they can not figure out why it shakes!
my trailblazer is crazy my temp gauge goes from 100° to 310° and after a while it goes to normal and wen that happens my check gauge light comes on and in the starts reading idle engine and engine coolant hot any body has an idea of wat this could be email me with answer at firstname.lastname@example.org please i would appropriate it