LIM Gasket Replacement [Archive] - GrandAmGT.com Forum

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kornfox
11-14-2010, 07:56 PM
Hi guys, (and girls)

I'm doing the failed LIM gasket on my 2001 Grand Am GT. I have the LIM off of the car but I am having a heck of a time cleaning the gasket area around the coolant ports. It seems that no matter what I do, I cannot get these areas "shiney". They are all a darker color and seem mildly pitted (especially near the failure location.) I've tried brake cleaner, acetone, razor blades and a detailing wire brush without luck. How perfect do these spots need to be? Do I need to bring this sucker to a shop to get machined?

Any advice would be great. If necessary, I can try to get some pics if it helps. I just couldnt find my digital camera. Thanks!

edit: pics added

http://i34.photobucket.com/albums/d115/kornfox/2010-11-14_21-20-23_229.jpg

http://i34.photobucket.com/albums/d115/kornfox/2010-11-14_21-21-00_725.jpg

silverbulletO5
11-15-2010, 08:20 AM
It doesn't need to be a perfect machined flat surface to seal but the smoother the better, back when i worked at the dealership we had a tube of filler that looked like gray silicone but it dried hard allowing you to fill in the pits then use a razor blade to scrape the excess off giving you a smooth surface. This was only necessary on intakes that had badly pitted areas though, if anyone knows what I'm talking about please chime in with a brand name etc. This could probably be done using JB Weld also but use at your own risk sort of thing.

kornfox
11-15-2010, 12:17 PM
Would I be able to lightly coat the gasket with some RTV on both sides? Will that be effective?

slw240sx
11-15-2010, 02:59 PM
a two part epoxy would also work, one that's made for bonding to aluminum.

silverbulletO5
11-15-2010, 03:39 PM
I've heard of guys using RTV to fill in the pits, use a razor blade to remove excess then letting it dry before installing the gaskets and LIM. It's you car just use your best judgement, If it were me I'd fill it in with JB weld or similar aluminum/metal epoxy.

AaronGTR
11-15-2010, 06:35 PM
Yeah, that looks too badly pitted to get a good seal to me. You could try using RTV on both sides of the gaskets, but it would be imperfect and might not seal well. I'd try the JB weld route, or see if you can get another type of epoxy meant specifically for aluminum (I know they are out there, might have to order it though). Fill in the pits then sand it down smooth, and you should be able to get a tight seal from the gasket. Next best thing would probably be just buying new parts.

kornfox
11-16-2010, 03:35 PM
Should I be putting the RTV on the gaskets themselves, or on the manifold so I can get it in the pitted areas better?

I'll drop by the parts store today and look into a metal filler as well.

AaronGTR
11-16-2010, 04:48 PM
Well, if you wanna go that route, I would put it on the outside edge (away from the coolant port) of the gasket itself. You don't want too much extra sealer in there that might come off and get in the coolant and gum things up. Also you'll have to let it dry overnight before you fill it with coolant and start it up if you do that. Otherwise the RTV will not set up and seal.

350rs
11-16-2010, 05:34 PM
its deff not recommended that you put ANYTHING on those gaskets. Use the smallest amount of any RTV you choose to use. I would look for this mystery product that fills the pits in aluminum. As long as it holds up to heat? Otherwise... maybe take the heads to a shop and have them machined a little so the pits are at least less of a problem. Would give you a chance to replace head gaskets too. Its probably an unnecessary step, but a little insurance goes a long way in my eyes.

AaronGTR
11-16-2010, 08:01 PM
Yeah, I really wouldn't go with RTV either. I'd fix the surface with something or get new parts or get them machined.

There are several high tech epoxies you could use, but honestly... I'd just try JB weld. I've used it in my upper intake manifold and it's still holding strong. It's resistant to 500 degrees so... should be fine. Just make sure the surface is very clean and rough before applying, and use as little as possible to limit the amount of sanding you'll have to do. IE try and spread it very smooth with a razor blade or similar item. And of course make sure you adequately cover up the oil galley and head ports before doing any sanding. Don't want that crap in your engine. ;)

stonemason90
11-17-2010, 03:44 AM
Yeah, I really wouldn't go with RTV either. I'd fix the surface with something or get new parts or get them machined.

There are several high tech epoxies you could use, but honestly... I'd just try JB weld. I've used it in my upper intake manifold and it's still holding strong. It's resistant to 500 degrees so... should be fine. Just make sure the surface is very clean and rough before applying, and use as little as possible to limit the amount of sanding you'll have to do. IE try and spread it very smooth with a razor blade or similar item. And of course make sure you adequately cover up the oil galley and head ports before doing any sanding. Don't want that crap in your engine. ;)

jb weld is your best bet. rtv isnt even really worth touching. itll just fail again in like 10-15k miles if that.