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LIM gasket metal/plastic


jakegday
09-06-2010, 07:46 PM
hello all. im going to be doing my lower intake manifold gaskets... i was looking at autozone noticed the plastic ones are cheaper then the metal ones. both Felpro brand. i am willing to spend the extra money but dont want to if there is no difference. so are the metal ones actually better, or will i be just fine with the plastics?

richtazz
09-07-2010, 08:49 AM
The metal ones are much better, GM offers them now and has discontinued the plastic framed ones.

BNaylor
09-07-2010, 09:28 AM
Felpro plastic framed is fine. That's all i use.
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jakegday
09-07-2010, 03:21 PM
well crap! 2 different answers from 2 very reputable members. can i get a 3rd?

BNaylor
09-07-2010, 05:41 PM
:lol:

The bottom line is it is your choice. Both work fine but no real proof the GM aluminum framed port gaskets work any better. The FelPro sure look nice too. :grinyes:

http://i5.photobucket.com/albums/y186/lizzywiz/DSC02593.jpg
LIM/UIM Job on our Regal going back 2 years.

jakegday
09-07-2010, 07:44 PM
ok quick question guys. after i replace these, i was told i should refill it with new oil and run it for a very short time, then change it again. do i need NEW oil to do this, or can i just run the current oil a little bit longer, then change?

BNaylor
09-07-2010, 08:48 PM
It depends. Are doing this job as preventive maintenance or do you have an issue with the gaskets?

jakegday
09-07-2010, 08:51 PM
i believe i have an issue with the gaskets. its either these, or a head gasket. i lose about a half gallon of coolant every 4-6 months. and when i cut my used oil filters open, the are warped/wavy as hell, suggesting that a good amount of moisture is getting in there.

BNaylor
09-07-2010, 08:59 PM
Then just to be sure after the job is complete I would use some Seafoam engine treatment added direct to the crankcase to the old oil providing that nothing falls in when you do the LIM gaskets. About 4-6 ounces and run for about 15 minutes then drain. Add new filter and oil.

Seafoam helps pull moisture and antifeeze out.

tblake
09-08-2010, 12:53 AM
I didn't know fel-pro made metal LIM gaskets for the 3800? I thought GM made metal, and fel-pro's are still plastic.

richtazz
09-08-2010, 03:28 PM
Tim, Fel-Pro metal framed intake gaskets- MS98014T

The fel-pro plastic framed gaskets (MS95809-1 for VIN-K, and MS95977-1 for VIN-1) are still an improvement over the OEM, because they have metal compression-stop washers to prevent overtorquing and subsequent cracking. I believe the higher strength vs lateral force of the metal frame over plastic frame make them superior, just as the new metal framed gaskets for the 3.1/3.4 have proven themselves more reliable.

tblake
09-08-2010, 03:54 PM
Dang Rich, if I'd have known Fel-Pro made metal ones for the 3800 I'd have used them in my 3800 instead of the stock GM metal ones. Oh well I guess. So far mine have been just fine.

richtazz
09-08-2010, 04:02 PM
The GM metal ones are just as good as the Fel-Pro brand, so you're good Tim. Unlike the other MS980xxT sets, the 3800 set doesn't come with the valve cover and upper plenum gaskets like the others do. I understand the valve cover omission, as it isn't necessary to remove the valve covers to do an intake on a 3800, but the upper plenum set should be included like they are in the 3.1/3.4 and 4.3/5.7 sets.

jakegday
09-08-2010, 04:50 PM
WOW!!! i cant wait to post pics of these!! they are bad! definitely in need of replacement.

quick question tho: obviously there is supposed to be oil between the lower intake manifold, and the engine. but is there supposed to be oil between the upper intake, and LIM??

danielsatur
09-08-2010, 04:59 PM
I like metal, because plastic is going to age and cause problems.
The oil in the Inake manifold is from a bad PCV valve.

jakegday
09-08-2010, 06:33 PM
hmmm, i put a brand new ac delco PCV valve in about 10,000 miles ago. the old one sounded (it rattled when shook) fine, i just did it as a maintnence thing... from looking at this pic.... do you think my new one is faulty, or is this maybe left over from before??
http://i2.photobucket.com/albums/y31/jakegday/100_4449.jpg


here are the gaskets.... the only question i have in regards to these is, are these stock?? you guys would know better then i would. if they arent, i am goign to wish i had gone with the metal ones....

http://i2.photobucket.com/albums/y31/jakegday/100_4448.jpg

danielsatur
09-08-2010, 06:37 PM
Just because a PCV valve rattles, doesn't mean that it's good.
It's like a check valve, the oil suppose to stay in the block.

jakegday
09-08-2010, 06:39 PM
soooo..... my new one is faulty? or could this be 10000 miles old?

BNaylor
09-08-2010, 06:44 PM
Your PCV could be good. The oil probably came a bad front bank LIM port gasket at Cylinder 1. That is where the crankcase ventilation feed is from. From there through the UIM plenum and to the PCV which obviously is mounted in the UIM plenum.

BNaylor
09-08-2010, 06:50 PM
:shakehead

A factual anecdotal note for fans of the metal framed LIM gaskets whether 3100/3400 or SII 3800. I did a job on a GM car (GA GT) with 3400 V6 engine with the revised GM metal LIM gaskets. The metal portions of the port gasket frames were pitted and corroded. Also, it looked liked electrolysis was taking effect eating away at the aluminum lower intake manifold. We were fortunate a ported and polished LIM was being installed. The old LIM was trash canned.

BTW - When I recommend plastic framed I do it for a reason and not pulling B.S. out of my rear end.


here are the gaskets.... the only question i have in regards to these is, are these stock?? you guys would know better then i would. if they arent, i am goign to wish i had gone with the metal ones....

Your LIM gaskets look like the stock OE plastic GM which are garbage. You can tell by the color of the rubber sealing. Aftermarket FelPro is red.

tblake
09-08-2010, 07:59 PM
Those gaskets are Horrible. All 4 coolant passages are blown.

And I agree with Bob, those are definately stock.

jakegday
09-08-2010, 08:38 PM
so will having that thin layer of solid black hurt anything, and how should i go about cleaning it off?

BNaylor
09-09-2010, 05:55 PM
so will having that thin layer of solid black hurt anything, and how should i go about cleaning it off?

Probably not but I'd clean up as much as possible. Try auto parts cleaner solvent (Gumout) or any spray carb cleaner. On my LIM I took it to a Magic Wand type carwash and hit it with high pressure soap and water. Then rinse and let dry.

Also, the black you see is probably not all motor oil. It could be old residual Dex-cool which bakes due to the engine heat and eventually turns black.

DrRadar
09-13-2010, 08:08 AM
I had a conversation with the local Autozone manager a couple weeks ago about LIM gaskets for my 99 GTP. They carry two different "quality" gaskets - one about $38 and the other about $75. I think he said both were Fel-Pro. He said that DEX-Cool causes typical plastic to deteriorate. The $75 gasket is made with a different type of plastic developed to tolerate the DEX-Cool, so lasts much longer.

I'm no expert here - you may want to investigate further yourself.

Oops...I think I may have stumbled into religion here...

Uh oh. Here we go again.

So, is the claim that DEX-Cool deteriotes plastic considered exaggeration by many of you?

I don't want to start a debate...I just want to understand what the debate has been.

tblake
09-13-2010, 10:06 AM
The main reason GM Gaskets blow is because of the shoddy gasket design by GM. Almost as if they want the gaskets to blow. Refir to my post below about those damn slits in gasket coolant passageways. Blame gets placed on dex-cool because its claim it can withstand 10yrs or 100k miles. Which if your driving in extreme conditions will need to be switched out sooner. Nobody does this. Plus it reacts with air differently and gells up into a brown substance when mixed with air. Which if you have air in your cooling system, you have a leak. I have seen GM owners who switch to the conventional green antifreeze right after they bought the vehicle, and yet the LIM gaskets still blow. Which switching from dex-cool to the green stuff opens up a whole other can of worms.

http://www.automotiveforums.com/vbulletin/showthread.php?t=958284

bjaymo3
09-27-2010, 07:26 AM
I had just replaced my LIM and plenum gaskets about 120 miles ago (yes, very short time). I discovered that I goofed up (way over-torqued) the install of the LIM and started getting coolant leak. Also, I had used the lesser-expensive fel-pro gasket from AZ and the end piece gaskets (light blue) turned out to be too long and very difficult to mount. Therefore, when I replaced again, I went for the high-dollar fel-pro from AZ and discovered the rememdy. There were the blue end pieces but also, two black end pieces with guide pins and were a perfect fit. (still no plenum gasket, however.)

My question is Do I need to replace the plenum gasket again as well. It appears to be in great shape (only 120 miles) but it was somewhat over-torqued as well. (finally figured out my torque wrench for the new installs). I realize that the standard answer is most likely to replace it. But at $33 (rockauto), I'd really rather not replace if not necessary.

Thanks for the adivce!

tblake
09-27-2010, 09:25 AM
If your car runs ok with no vacuum leaks, you should be fine.

I hope you inspected the Upper intake manifold for warps around the EGR valve pipe before you re-installed.

bjaymo3
09-27-2010, 05:59 PM
Thanks for the quick answer. I looked over the manifold pretty well and nothing jumped out as being irregular. Everything is now re-installed and after I let the LIM cure for more than 24 hours, I started her up today. The end result is that it sounds fine. I'll be on the lookout for leaks, of course.

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