LIM Blues

[Nitro23]

I've put just over 5k on new LIM and head replacement. Motor is leaking oil.
At first I thought the A/C compressor was leaking , but A/C still working good. Just did an oil change and thought maybe the filter was screwed up. No such luck. It's taken several days but I pinpointed the leak to the LIM valley behing the PS pump. I must not have placed a good enough RTV bead for sealing the bottom. Talk about shooting myself in the foot. Anyway, I used the GM kit, and perhaps mayby the gasket went bad - won't know till I get her apart.

This is the fifth one I've done and first problem. I just hate doing things twice.

I am going to use the Felpro Pro kit and the new Push Rod tool this go around. Will let you know how it works out.

[merc81]

Ouch.
Maybe it was the rtv bridge that was the problem? I really hated the hand work in getting that thing the right size and shape. I'm not very talented with my hands so squirting that stuff out to the required bead size was a pain for me.
Anyway, I've been burning some time reading over the forums and noticed that nobody really pointed out a good source for the gasket--I got the kit for $39 at 1aauto.com. I'd have to go look in the trash at the box to say if it was felpro or not, but it was metal not plastic and the bolts came with sealant applied already.

Look at the bright side--you're an expert by now and this should only take you 3 - 4 hours!
John

['97ventureowner]

I've heard of better results with the Fel Pro gaskets over the OEM ones. There are many sources for the gasket and it would take a little work to find the best source whether it be local or online, whatever your preferences. You could call your local parts stores and compare prices, and online you could check out various sites that carry the gasket and see their price with shipping, and compare them that way. I've seen some members mentioned that they found their gaskets on amazon.com and that the price of the gaskets qualified them for free shipping. ( Qualifying purchases of over $25 on amazon.com gets you free shipping.)

[meggabad]

Nitro, sorry to hear your seal didnt take, that really sucks! As you know, I have mine tore down to the block right now, and couldnt imagine doing all of this work only to do it all over again in a few months. What a nightmare!

However, since there seem to be several of you here who have done this job, I was kind of wanting to see if there were any reccomendations out there as far as what RTV to use. I was sort of planning on using the permatex high temp copper RTV. I have used it many times in the past and always found that it works well on just about everything. Sort of interested in what others think. Not trying to hyjack your thread or anything, just thought it was a good question to ask since that seems to be what failed on your motor.
-Drew

[Nitro23]

I used some kind of gray GM RTV I got a while back. Not sure what it is. Never had a problem with it. I probably wasn't LIBERAL enough with it. So I blame myself not the RTV for my leak.

The Felpro Pro kit has Black RTV included - not sure if it's the Ultra.
Ultra Black and Ultra Copper would be the best you can use.

[Nitro23]

Problem was lack of RTV at the head LIM joint on the front pass side of the valley. My RTV bead stopped abut 1/4 inch short. Anyway I changed my beading procedure. RTV'd the 4 corners first, then installed gasket and pushrods, then RTV'd corners again, then ran the deck bead. I used the whole tube provided. This sucker is not going to leak oil from the deck again.

I really like the felpro gasket. After putting in the GM Gaskets previously, the Felpro is definitely a better gasket. The one I used was the metal one. I highly recommend using this gasket over all others.

The Felpro RTV is good up to 400 degrees. This should be more than adequate, because if this particular motor reaches 400 degrees it's toast anyway. I think this is equivalent to the Permatex Black RTV, and probably is what the Felpro marked tube is.

Ultra black is good up to 500 degrees.
Ultra Copper is good up to 600 degrees.

With the Felpro, it really seemed to torque down nicer. Took a lot of rotations to get to the final torque specs. Easy to tell the whole LIM was securing properly.

Still took me start to finish 10 hours, but I also replaced rear shocks, water pump, and T-stat. I did the t-stat the hard way - after istalling the LIM. Only because I put the LIM on without the T-Stat housing for easier placement of the LIM on the install. Won't do that again...
Change the T-stat when the LIM is out.

If you are replacing the LIM bolts, the fuel injector rail has to come off.