Page 1 of 2

Better intake manifold gaskets??

Posted: Thu Aug 15, 2013 7:43 pm
by 96B-Mike
Ive heard berettas are well known for failure of intake manifold gaskets..true or not..ive dealt with the pain. Before i swapped out the motor..my 3100 blew intake gasket around..70k?..got a new one then 30k later the motor blew..swapped a 3400 in (refurbished motor) with still the 3100 upper/lower intake..so 15000miles later..again the intake manifold gasket blows?? im not stressing it too much since i am going to put in the 3400 upper and lower intake..

so my question is..is there a better gasket out there so i can prevent this from happening again!?

thanks!!

Re: Better intake manifold gaskets??

Posted: Thu Aug 15, 2013 7:53 pm
by heavywoody
Get the updated metal ones; they should all be that at this point.

Re: Better intake manifold gaskets??

Posted: Thu Aug 15, 2013 8:59 pm
by woody90gtz
Metal Fel-Pros are a must...

Image

Re: Better intake manifold gaskets??

Posted: Fri Aug 16, 2013 8:22 am
by 3X00-Modified
I still run GM 3500 plastic ones... never had a problem.

Biggest problem is don't over torque the bolts, and use LOCTITE so they don't loosen up.

Re: Better intake manifold gaskets??

Posted: Fri Aug 16, 2013 9:01 pm
by Money pit Beretta
Blue or red locktite?

Re: Better intake manifold gaskets??

Posted: Sun Aug 18, 2013 10:00 am
by 3X00-Modified
Blue, I use red only on the torque converter bolts.

Re: Better intake manifold gaskets??

Posted: Sun Aug 18, 2013 11:01 am
by Money pit Beretta
Yeah red would be overkill.

Re: Better intake manifold gaskets??

Posted: Sun Aug 18, 2013 9:52 pm
by 96B-Mike
aight cool, thanks guys

Re: Better intake manifold gaskets??

Posted: Tue Oct 15, 2013 4:16 am
by Rettax3
Yes, I realize this is an older thread and the OP's issue has already been resolved... But I wanted to put it out for the community that the Dorman metal gasket sets are decent too. I've only used one as yet, but when I start working on my Z-26 again, I will be getting another set to update its' engine with metal LIMGs, (and the small-port 3100 in my '86 Fiero GT too) -the Z has blown the plastic sets twice since I've owned the car, before I swapped to the 3400 intake. And yes, I torqued the bolts exactly to specification -it didn't matter because GIGO (old-school computer lingo here :wink: ), and making engine gaskets out of plastic is definitely a garbage idea...

For the M-code 3100s, as issued to the '95+ Berettas with ball-type rockers, the Dorman part # for the complete set is 615206, and it even includes new bolts (with thread-locker :wink: ), valve-cover gaskets, and a selection of EGR gaskets.

For 3400s and J-code 3100s, Dorman's part number is 615205.

Rock Auto carries these sets for ~$40, about 2/3 the price of Fel-Pro (who p!$$es me off just be selling the plastic-crap still, and inflating the price of the metal gaskets so much that people think, "Hmm, maybe I'll try those plastic gaskets again..."). Worth every penny, IMO.

Just FYI...

Re: Better intake manifold gaskets??

Posted: Tue Oct 15, 2013 8:57 am
by 3X00-Modified
Still rocking stock 3500 GM PLASTIC gaskets... ;) I can't use these metal ones because I ported my intakes to match the GM ones which have larger openings...

Re: Better intake manifold gaskets??

Posted: Tue Oct 15, 2013 1:54 pm
by Rettax3
3X00-Modified wrote:Still rocking stock 3500 GM PLASTIC gaskets... ;) I can't use these metal ones because I ported my intakes to match the GM ones which have larger openings...
As stated before, I don't have experience with the 3500 -I've never had to work on one. They may actually be designed better than the 3100/3400 sets, or maybe they are just built better. It is also possible that you've just been lucky. I'll bet more of these gaskets don't fail over the course of the engine's life than do fail, but the point is that it is a weak-point in the design, and there have been so many LIMG failures in the 3X00 series that should not have failed. It is almost impossible to blame installer-error exclusively as many of these gaskets failed from the factory before any other major work was required on the engine. The 2.8/3.1 MPFI engines did not have this problem, so GM took a step backward with the newer and more powerful 3X00 engines, and that is intolerable to me.

I am glad you haven't had a problem though, and hopefully you won't have one in the future. :good: Could you use the metal gaskets and use a hobby-knife to open up the rubber seals to match your ports? (Out of curiosity -if you have no problems and have confidence in the OE style, then use what works for you. :beer: )

On the LG5-3.1/LA1-3400 hybrid in my '90 Turbo 'Retta, since I have the MPFI heads and intake, I had to use the MPFI gaskets, which work great. My heads/intakes are all ported out beyond the gasket size, and the gaskets are slightly opened up too. Normally, the gasket is one piece connecting across the engine through the lifter valley, but on my engine it was cut into two halves and then pinned in place with small pieces of crushable hollow plastic tubes to keep the gaskets from shifting during installation of the lower intake plenum. I'm sure with all the work I did to it, that top-end probably flows almost half as well as a stock 3400 intake... :roll: But at least it doesn't use plastic gaskets... :wink:

Re: Better intake manifold gaskets??

Posted: Wed Oct 16, 2013 12:27 pm
by Slinky
I have a set of 3400/3500 lower intake gaskets i will sell, they are plastic unused, and as Jon said they will work fine if installed properly.

pm me if interested

Re: Better intake manifold gaskets??

Posted: Wed Oct 16, 2013 12:59 pm
by 3X00-Modified
3400/3500 gaskets are not the same so they are one or the other... lol

Re: Better intake manifold gaskets??

Posted: Wed Oct 16, 2013 1:47 pm
by Slinky
I got so many gaskets and engine parts laying around ill have to check which ones they are ha

Re: Better intake manifold gaskets??

Posted: Wed Oct 16, 2013 2:11 pm
by Rettax3
Slinky wrote:I have a set of 3400/3500 lower intake gaskets i will sell, they are plastic unused, and as Jon said they will work fine if installed properly.
Well darn, if only someone told the assemblers at GM that... :D Several thousand (or tens of thousands?) of engines could have been saved from oil-contamination and probable bearing damage. But hey, the ~60k mile 3400 block in my '90 turbo 'Retta only cost me $60 at the junk-yard several years ago, complete with all accessories computer and wiring harness, because they had already sold it once and it came back with 'blown head gaskets' that were actually the failed LIMGs, so I'm not saying I haven't had good opportunities. Too bad the crankshaft was eaten by the lack of actual oil because of the plastic LIMGs... :roll:

Slinky, are your gaskets the updated OE ones with the brass inserts around the bolt-holes, or are these first-run types without the bolsters? The brass insert ones are supposedly an acceptable replacement because the plastic has some better support that keeps them from cracking under the pressure of (correctly torqued) LIM bolts and the repeated heat-cycles of routine engine operation, although I personally would still go with steel gaskets, but GLWTS either way.