Engine and trans mounts replaced. Other issues?

**SinisterFootwear** · 03-30-2016

05 GP GT, 105k miles. In December I replaced trans mount and lower left engine mount. Both had deteriorated rubber, but no oil contamination. No oil leaks. This week I had to replace the upper right torque mount bracket, as it had failed at the weak points, in front of each of the back bolts into the cylinder head. I replaced the stock aluminum bracket with a Dorman cast iron one, which is a lot heavier/sturdier. Wondering if there could be another issue why almost all the mounts would fail in a short amount of time, or is it just time/miles, and if I should be looking for further issues contributing to mounts blowing out. I've owned this vehicle for 15 months, prior owner was the only other owner. By all accounts they had taken care of the vehicle very well, as have I, and it runs and drives practically like new. I have a 98 firebird that I've owned for 18 years and its still on the original mounts, so that's one reason I'm questioning it. Have never had a mount issue with any other vehicle I've owned til this one.

Thanks for your help!

**Impala131** · 03-30-2016

It might just be a domino effect... one mount goes out, and it puts additional stress on the remaining mounts, causing them to fail faster.

And the factory aluminum engine mount is junk... snapped one on my Impala, replaced with a junkyard one, broke that too. Replaced with a junkyard L67 (cast iron) mount bracket, no more issues.

**SinisterFootwear** · 03-30-2016

That's kinda what I'm assuming. Well, only 2 other mounts can go on it! The upper right bracket was a ***** because of that one bolt that angles towards the upper IM and has practically no clearance to get a wrench on it with the injector right next to it and angled over the top of the bolt head. The others appear rather simple to replace... so there's that...

**kuhnzoo** · 10-27-2016

Originally Posted by Impala131

It might just be a domino effect... one mount goes out, and it puts additional stress on the remaining mounts, causing them to fail faster.

And the factory aluminum engine mount is junk... snapped one on my Impala, replaced with a junkyard one, broke that too. Replaced with a junkyard L67 (cast iron) mount bracket, no more issues.

I just picked up a cast iron mount / coil bracket to replace the broken passenger side bracket on my 2000 Impala. Any tricks to this swap? Or does it bolt right in? Thanks!

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**SinisterFootwear** · 11-06-2016

Originally Posted by kuhnzoo

I just picked up a cast iron mount / coil bracket to replace the broken passenger side bracket on my 2000 Impala. Any tricks to this swap? Or does it bolt right in? Thanks!

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Did you get the bracket for the supercharged 3800 or the N/A 3800? The one that installs on the supercharged is fairly simple as it bolts up under the coil pack module. The one that bolts over the valve cover onto the manifold is kind of a *****. That is the one I replaced, and even though I have no issues with valve cover gasket I wish I had done the gasket too because I will not look forward to removing/reinstalling that mount again.

**kuhnzoo** · 11-06-2016

I think it's from a sc 3800 since it bolts to the end of the head. However, when I took THE ICM and coils off the OEM aluminum ICM mount, it does not bolt right onto the cast iron mount.

My coils and ICM are held on the OEM mount with 6 little bolts on the coils.

Any ideas?

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**kuhnzoo** · 11-06-2016

Here is the cast iron mount. It is the combination motor mount and coil pack bracket.IMG_20161106_173534294.jpg

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**kuhnzoo** · 11-06-2016

The bracket bolts on the end of the head.

View of the col pack mount area. My ICM and coils will not mount to the three holes shown.

IMG_20161106_173541755.jpg

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**Scottydoggs** · 11-06-2016

re drill the coil mount. i had to re drill all 3 holes when i modded mine and moved the icm over a 1/2 inch or so.

**kuhnzoo** · 11-06-2016

Problem is that my ICM does not bolt to the mount in the OEM configuration. It is sandwiched between the 3 coil packs and the OEM coil pack mount. Each coil pack is fastened with two small diameter bolts that go through the ICM and thread into the OEM mount.

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**Scottydoggs** · 11-06-2016

so your icm plate dont look like this is what your saying? if so you'll need to grab one up i guess.

**kuhnzoo** · 11-06-2016

Yep. I just found that setup doing a Google search. Apparently, I need this adaptor baseplate and the bolts.

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**Scottydoggs** · 11-06-2016

its just a supercharged icm plate. i guess they are not all the same. you'll want to grab the three nuts and bolts too when you snag another one. and maybe the coil bolts.

**kuhnzoo** · 11-06-2016

The NA 3.8 in my 2000 Impala does not have this baseplate. The oem aluminum mount on the end of the head acts as the baseplate and the coils bolt to it (sandwiching the ICM).

Now I need to find this baseplate and bolts. Or make one from some aluminum plate.

Thanks for the info. Have a spare baseplate and bolts by chance?

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