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Deep Vibration at idle on 2003 TB

71K views 52 replies 28 participants last post by  Anto3 
#1 ·
I have a deep vibration at idle and in gear. When I place it in neutral or park the vibration used to go away. Now it is there but not as bad as when in gear. When I accelerate it goes away. I have cleaned the throttle body. It is not that type of vibration. I have had two shops check it. The shop its in now is about to check the cam shaft pulley. They also replaced two motor mounts which did not stop the vibration. They did say something about the exhaust being tight. Any guesses or suggestions?
 
#35 ·
Other ideas

Could be motor mounts. There are several references to bad motor mounts causing the vibration. Especially if it occurs in Drive, but goes away in Park and Neutral. I have the same issue and Motor Mounts (OEM replacements only) are my next item to replace.

You may also want to look at rocks in the transmission mount. That sometimes is a cause.
 
#37 ·
Motor mounts

The vibration on my Bravada was worse in the winte. The mounts compress and get harder in cold weather. As it has warmed up or the outside temp increases, the vibration is less. Replacing the mounts with OEM parts was the answer in my case. Maybe in yours too?
 
#38 ·
I had the same problem. It was my motor mounts. I ordered some new ones from gmpartsdirect and swapping them out stopped about 95% of the vibration while at a stop in drive.

I have a new transmission mount that should be delivered today so I'll swap it out after work and hopefully that will resolve the small amount of residual vibration left.
 
#39 ·
I will add my resolution. Had rough idle for a while, with mostly 300 code. Went to dealer and they "found" compression in cylinders 1 and 2 is less than on others. They had only one solution - replace head.
Went to a friend in local Big 10 Tires and explained to him exactly whats going on. Misfiring mostly when I stay on Drive at light or begin to drive.
he recommended to try and replace thermostat. According to him, engine is getting more gas to increase the temperature because thermostat is telling it is not warm/hot enough. This is causing a misfire on low rpm.
After replacing thermostat, everything back to normal. My 130K miles engine is quiet as new at 600 RPM idle and even MPG improved.
:thumbsup:
 
#40 ·
i was gonig nuts yesterday....we had some decent rain here in san diego, so i decided to make a big splash behind the sonic burger....i get home, rinse the truck (while on) and shut it off....i get in the truck about hours later and i get that damn vibration while in a moving gear...it would come and go as it pleased....i dumped some fuel injector cleaner and filled up (needed it anyways) and it was still there, and drove me nuts....
thank god we have trailvoy.com, i bet some rock is jammed up in the mount, although i did see other things on this link about a cam-position sensor... which i may change anyways only bucks at autozone and im going to clean the tbody again after the mobile 1 change on friday...i just hope there are rocks in the mount...that would make my life easier
GO TRAILVOY!
 
#42 ·
SOLVED! engine vibration when in drive

Have been dealing with engine vibration on my 02 Envoy (134k miles) for some time that just kept getting worse. At first it was noticeable only in drive but later became evident upon start up, worse in drive, and least in reverse. Replaced engine mounts/transmission mount to fix my problem. My mechanic first replaced transmission mount but it failed to solve the issue. Next replaced engine mounts and all vibration is now gone. Would recommend reversing the order after you check for other vibration sources. My mechanic has also encounted vibration noise on Envoy/TrailBlazer due to vibrating heat shields/etc under the body. Mine were all tight. Good luck!
 
#43 ·
Vibration In Drive, Not Reverse....listen to this

So I take my car into the dealer BOB KING, Wilmington, NC or should I say "Rip Off King". I tell them I'm 100% sure it's the motor mounts, please have a technician look at it and if he agrees replace them. They call me later in the day...."nope the mounts look fine, we are convinced it's the Throttle Body". As luck would have it I had just cleaned the throttle body 3 weeks in advance so I know that part of the engine well. I told them if they were 100% go for it, $478 later....I start the vehicle at the dealer and pull it right back into the service shop, still vibrating. Now I'm getting hot! Well, it's a Friday evening and no one of any significance is around. So I leave it over the weekend to assure they don't try and blame me for their inadequacy. Bright and early I'm in there Monday morning and meeting with the service manager. I'll never forget the quote, "I don't see as I owe you anything". Okay, now I'm white hot! After arguing for a solid 30 minutes, he agrees to put my old throttle body back in and refund my money. I agree, but not until I've personally seen my old throttle body, I could tell it was mine due to the fact it had some scotch brite marks on the flapper. The mechanic says, "See it's locking up in this position." I look him straight in the eye and said, "Can I borrow a torex screw driver that fits the screws in the flapper?" He agrees, so I turn the throttle body flapper to the sticking point, losen the screws, then tighten them back down. It opens and closes smoothly, I hand it back to him and say, "Fixed, now put it back in and do it right". Finally they get it back in, I go out to the car to check they put it back on right before I leave, and they left the bottom hose connection off!!!! Now I know it will take me days to calm down!! Back into the shop I go. I stand there while they fix it this time, I go into the parts department, buy the motor mounts and will install them this weekend. I have lost all faith in this once bankrupt company!!! Imagine the anguish had my wife or most other people I know taken the car in for this repair!?? BOB KING, WILMINGTON, NC total crooks!!!
 
#46 ·
Well, it was a marathon, but at least I finished the race!

Well, I have to thank you folks, had it not been for your detailed coaching I would never have had the confidence to dig into my vibration issue.

Unfortunately, my motor mount/new plug change took about 16 hours total. I'd have to say the main reason it took me so long is I don't have a great mechanics ratchet set, I spent too long trying to force the mounts in vs. giving up and just removing the upper support bracket, the fan shroud is a pain, oh and the wire way over the first plug (closest to the front of the car) is a piece of work as well.

With respect to the mechanics ratchet set, just be sure you have deep and shallow sockets for metric sizes up to 21mm. I had a couple of trips to the store to buy the next size up. Oh, and go ahead and get a breaker bar while you are at it. I relied heavily on a pipe to cheat my undersized 3/8" ratchet.

Jacking the engine up seemed to go fairly smoothly, but I could have saved a lot of time if I'd jacked it up an appreciable amount and then just taken the upper brackets off the motor mounts. I ended up going that route after realizing I had essentially take the top of the engine off and was still not able to get the new mounts in place.

The good news is the mounts worked. My ride is much smoother. If I sit in drive and am very quite, I can still feel a very slight vibration, but nothing close to what it was before. I have to wonder if it has anything to do with the oil I found on the threaded portion of the old plugs on cylinder #5 & #6?

After fighting the fan shroud, I'm scared of the fan clutch replacement everyone's talking about. Hopefully mine will hold out long enough for me to build back my confidence.

Oh, by the way, my "faulty throttle body" that the dealer wanted to replace with a new one is operating flawlessly! Again, if you find your throttle body sticking at any position, turn the "flapper" to the stuck position, loosen the two screws holding it, and then tighten them back. It cured my sticking problem and saved hundreds!
 
#47 ·
Vibration issue

I read your post Eagle Scout. I found out the same when it comes to the mounts. The engine required elevation to the point it would have hit the firewall. I (and my buddy who's a 30 year mechanic) just took off the top mount brackets and it made it a whole lot easier. We didn't even remove te fan clutch, just loosened things and detached the oil lines from their clips on the radiator. The tranny mount was a separate issue and we conceded to another time. Seems there are frame issues on my Bravada which wreak havoc with this replacement. The manual does not reflect this and it is better to have the SUV on a lift. Garage workshops are a challenge. Congrats on getting your mounts done!!! :tiphat
 
#49 ·
Same vibration

I have had the same on my TB EXT W/ 107k vibration in drive or reverse but only when stopped brake applied or coming to red light or stop sign specially when driving through rough streets with pot holes. I replaced most of the suspension in the front, upper control arm, lower with brackets, links tie rods, shocks and nothing did it, i just could not figure it out so i finally gave in today and took it in to the Stealership since my warranty expires soon (still have to come out of pocket almost 300) they are going to replace both mounts and i will let you know if it does the trick i hope this is it will let you all know tomorrow.
 
#50 ·
Problem solved

:woohoo:SO like i said i took it in and new OE mounts and my TB is like new, runs, drives, idles, even cranks smoothly. I am glad i did not go with aftermarket mounts and i would have never known they were not cracked or loose like other mounts i have changed before but you can notice the difference from the old ones to the new one on how they were compressed. :woot:
 
#51 · (Edited)
New member, same issue

First off, hello to all and thank you for having such a great forum with informative information.
Yesterday, my wife left for work in our 2006 TB, up the long washboard gravel hill like she does every work day. Only this time when she reached the top and stopped at the stop sign of the first intersection, she noticed that the entire vehicle was vibrating. She didn't feel anything when she pulled out, so she drove about 1500ft to the second stop sign where the main road was, and it still did it. She then called me at home and said she was turning around because she didn't know what the issue was "all of the gauges are fine, no low tires (we get that quite often due to the gravel), so I am coming home to have you check it". When she got home I just told her to take my car to work and I would drive the TB to work and check things out.
She wasn't kidding about the ENTIRE car vibrating. Holy smokes! Well, I talked with a co-worker and told them that it seemed sort of strange that it happened all of the sudden, while going up a washboard gravel road (which is beating our car up pretty bad). I even commented about the vibration being similar to my full sized blazer (wheeler) when I tore the trans mount in half and it was sitting on the cross member.
After doing a very quick search on the internet for "Trailblazer vibrate idle", I got your link. I am hoping that the OEM engine mounts and Trans mount (for good measure) will cure this problem.

Thanks again for the pages of data and useful information on this site!!
 
#53 ·
Had the Same issue for about 2 months
Replaced Motor mounts, plugs, clean throttle body, relearned ECM
Idler pulley , belt tensioner, exhaust mount.
After scratching my Head I decided to sepperate the engine from the trans
The vibration stopped. I learned that the Torque Convertor was no good
One. Of the weights fell of causing the vehicle to vibrate. Replaced the Torque
Convertor and the Flywheel and all was perfect. Like new.
 
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