I just wondered if anyone had any recommendations on what site to buy new motor mounts from. I would like to get them cheap but still decent because I had heard the after market ones do not fix vibration problems. Anyone who has any expierence please let me know....Thanks.
Recommendations for where to buy Motor Mounts
- Thread starter Lacher
- Start date
floridafitz
Member
Replaced mine at the stealer before I knew better. It is true our most experienced members highly recommend OEM only for this fix. Check out this eBay link and look at other OEM sources.
Chevy GM Olds Saab Trailblazer Envoy Motor Mounts GM C228 FE Qty 2 | eBay
Chevy GM Olds Saab Trailblazer Envoy Motor Mounts GM C228 FE Qty 2 | eBay
jeffro312
Member
Be carefully on eBay lots of fake china stuff on there.
Just go to the stealership there only like 80 a peice I think...
Just go to the stealership there only like 80 a peice I think...
jeffro312
Member
jeffro312 said:
Is there actually a defect of some sort in the design of the other non-oem ACDelco motor mounts? I am curious what the actual problem is. I would think that if the problem is that they are stiffer then to me that would be a good thing because they are made better.
And also, if there is some type of vibration at idle that is really bad then I would suspect an internal out of balance issue rather than engine mounts. I would be looking at compression, spark, etc... For instance, you don't see engines on test stands hopping around the room due to using no motor mounts.
jeffro312
Member
Its a particular 10htz vibration when in gear that signal motor mounts and experience from people who have tried after market have proven factory gm mounts only fix.
Just not made the same probably a bad comparison but we use ac delco plugs because they've been tested and proven so why throw Bosch in if they are known not to solve problem. Get it
Just not made the same probably a bad comparison but we use ac delco plugs because they've been tested and proven so why throw Bosch in if they are known not to solve problem. Get it
jeffro312 said:
Hmm. At idle 600 RPM / 60 seconds equals 10 RPM's per second. A 10 hertz vibration is 10 cycles a second. I think what most people are describing is a 1 Hz vibration or once a second.
The defect is that they are stiffer. Motor mounts are not for simply keeping the engine from departing the vehicle. They were computer designed to damp out a rotational oscillation that depends on the exact mass and resonant frequency of the engine/tranny/driveline/diff/axles/rear brakes. If the resonant frequency of that system is 9 Hz, but the idle RPMs are never below 600 RPM, then the natural resonance of the system is never going to be experienced. The reason that motor mount problems usually (until the mounts are really far gone, collapsed, and stiff) go away in NEUTRAL and come back in DRIVE is that putting the tranny in neutral changes the rotational mass of the system. It disconnects part of the tranny, driveline, and rear axle. So the resonant frequency changes and can't build up to a noticeable level at the 600 RPM idle. For a few weeks while I waited to get my motor mounts in, I just used EFILive to change my idle to 750 RPM and it made me feel better to not vibrate at lights. Not everybody has that tool, though.CaptainXL said:
The aftermarket vendors never seemed to "get it". That's why in this case, OEM GM mounts are the solution.
Lexus_burner
Member
- Apr 30, 2013
- 1
I've used the "RockAuto" Anchor brand mounts. They were better than the bad OEM mounts but still
had a lot of vibration transmitted to the chassis. Get the OEM's from here-->
2002 Chevrolet Trailblazer ENGINE Mounts Mounts GmPartsShop.com
Link is for a 2002 TB. change you year model etc as needed...
had a lot of vibration transmitted to the chassis. Get the OEM's from here-->
2002 Chevrolet Trailblazer ENGINE Mounts Mounts GmPartsShop.com
Link is for a 2002 TB. change you year model etc as needed...
Also are there two or three motor mounts? I have read both just wondered so I can order them for my hubby to do the work.
jeffro312
Member
Lacher said:
You have two motor mounts left and right and a transmission mount. Motor mounts are usual culprit I'm sure it wont hurt to go mount crazy and get tranny mount while your at it although I think that one is more work but not 100%
The vibration is in the same axis as the crankshaft which runs front to back. The engine rotates more than it's supposed to at idle. If you have somebody sit inside with it in gear, and foot on the brake, the vibration should be at maximum. One good place to look closely at the engine is on the intake manifold, at the bolt noted by the yellow arrow. (not my engine - it's way too clean). See how much it looks like a hummingbird wing, moving back and forth. Have the driver put the transmission in neutral and see the amount of fuzziness go down as the amplitude of the vibration gets less. If I remember right, a good engine will vibrate around 1/4" while in DRIVE, and a bad one is 1/2" or more.Lacher said:
Bring a screwdriver near that bolt head, and as the engine vibrates, it will whack into the screwdriver at the 10 Hertz (10 times a second) that we're talking about. Like a mini machine gun noise.
Attachments
Metalastic is/was a good isolator. My Jag had 11 of them- 4 front subframe mounts and 2 motor mounts attached to the subframe. This gave double isolation from the engine to the cabin. On top of that, the 12 cyl engine was naturally balanced so it ran smooth, very smooth.
The other 5 mounts were for the rear cage and xmission mount.
The other 5 mounts were for the rear cage and xmission mount.
Experience over the years on both forums shows that those guys will advertise parts at exactly wholesale price to sucker you into the purchase if you're only looking at the parts price. Then they rip you on shipping charges. Always compare the "as shipped" price on their stuff. I think they make the majority of their profit on the shipping charge.triz said:
The one I buy from is parts4chevys.com, which redirects to GmPartsShop.com - General Motors Parts - OEM GM Parts ? Chevy Silverado Parts - Factory GM Parts. They charge a little more for the part, and a bunch less on shipping, which I believe is a MUCH MORE honest business model that I prefer to encourage.
Compare the two and see if I'm still right.
Mooseman
Moderator
I've dealt with GmPartsShop in the past, great customer service. They're a real dealership in Phoenix and have a real phone number to call a real parts counter person. Such good customer service that when I ordered a camshaft actuator, they emailed me to confirm that was what I wanted instead of the usual CPAS. When there was a delay in the refund for the core of the old actuator I returned, called them up and fixed it right then.
And they ship to Canada, unlike GMPartsDirect. $121 for the actuator vs. $300+ in Canada, well worth it.
And they ship to Canada, unlike GMPartsDirect. $121 for the actuator vs. $300+ in Canada, well worth it.
so,... what about the tranny mount, is it necessary? mine is at 103k miles as of now and i have this vibration so i need to buy the engine ones, but what about the tranny one? does that one gives problems, fail or something?
jimmyjam
Member
- Nov 18, 2011
- 1,634
nah, the trans one isn't going to cause vibration unless its torn. visually inspect it, see if the rubber has cracked and rotted however it should be fine.
The first one to go is the passenger side engine mount, the heat from the exhaust manifold cooks that one way before the driver side.
The first one to go is the passenger side engine mount, the heat from the exhaust manifold cooks that one way before the driver side.