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Lower Intake manifold leak gasket questions

Warrant

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June 14, 2010
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City, State
Layton UT
Year, Model & Trim Level
2000 Sport
This is a follow up to this thread - http://www.explorerforum.com/forums/showthread.php?p=3091399#post3091399, I made a new one since search didnt answer my questions, and someone may have the same questions. I'm working on a 2000 4.0 OHV

I got the lower intake off tonight, definitely a major leak out the back, can see it clear as day with a mirror down the head, and the gasket was deformed/split too.

I have two questions:

The LIM gasket that came off is one piece, interconnected at each end and across the valley in several places. My felpro kit LIM gaskets are separate to each side. Is this correct? the only thing sealing the LIM to the block would be RTV..

-----

The other question is while it was obvious where the leak was to the outside, its not so obvious where its getting into the oil (it could still be the LIM, and I just cant see it), so is the only other possible area for getting coolant into oil along the top edge of the head gasket (into the lifter valley).

Below the top edge of the head gasket (down from the lifter valley to the outside of the block), is just cylinders, and coolant passages right. So if coolant was leaking down there, it would be either into the cylinder, or to the outside of the block, not into the oil. (Unless if its getting past the rings, which I would think would be unlikely since it would get burned before then?)

What I'm trying to figure out is if I need to go farther and pull the heads (which I'm not interested in doing if I don't need to), if my logic is correct, and I see no leaks around the head, and the plugs look good, AND I cant tell if its leaking from the head gasket into the lifter valley, then I should leave the heads alone right?
 



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The newer FelPro LIM gasket kits include a tube
of sealant to replace the rubber end pieces. (The
older end pieces tended to keep pressure on the
LIM and cause leaks, that's why the kit was redesigned.)

Was the engine missing upon cold startup?
Were there bubbles in the coolant resorvoir while running?
Gasoline odor coming from the coolant resorvoir?

If the answers to the above were all no, then the
LIM gasket was probably the only failure, especially
since you found the obvious leak.
 






Thanks for the replys, no indications like you mentioned, is it better to use the rtv vs the rubber ford gasket?
 






Thanks for the replys, no indications like you mentioned, is it better to use the rtv vs the rubber ford gasket?
I like using Ford parts when possible, but my experience
with LIM gaskets has only been with FelPro. I used the
Felpro kit with the black RTV on mine, and it seems to
be doing well so far, with no leaks.

RangerX's repair thread is a good one to go by. Lots
of good info there. One thing to stress is to torque
the LIM bolts in the correct sequence and stages.
That and making sure the gasket surfaces are clean.
 






good deal, that's what I'll do, everything going back together tomorrow.

What do you torque your rocker shaft bolts to?

My ford manual shows 22 lb ft and then an additional 90 degrees, I don't have a torque angle meter but it wouldn't be a big deal to get one (this isnt something I could eye ball is it?). However it would be a bonus just to torque them with a good old fashioned torque wrench. Searching, I've found most say the 90 degree's, but in this thread a guy mentioned his book shows 46-52 lb ft and hasn't had problems with that spec http://www.explorerforum.com/forums/showthread.php?t=104848&highlight=rocker+torque

I also found this http://www.autozone.com/autozone/re...er-Arms-Roller-Followers/_/P-0996b43f802e41f2 showing 46-52 lb ft as well.

Cam across several people who say they've stripped the threads with the rocker bolts and that not a option for me (which I've done before doing the TTY stuff on new bolts) which makes me want to go with whichever is less and call it good. (BTW they were a bear cat to loosen! had to use the megabreaker bar, I'd say it felt like more than 52ftlbs...)
 






I'm not a fan of TTY bolts either. When I did my
head work, I simply used a torque wrench and
watched the angles. The last 90* pull works out
to be about 90-95 ft lbs, so that's what I used
on the headbolts.

For the rocker bolts, I used about 45 ft lbs with
lubed bolts. The bolts aren't that large, and I
was afraid of stripping threads.

It's best to tighten the rocker bolts in stages too,
to prevent warping of the rocker shaft. When
things started tightening up, I went 1/2 turn at
a time on alternating bolts untll the final torqueing.
 






Well its all back together. Going to try to start it up tomorrow.

For the rocker bolts 52ftlbs was a lot less than 22ftlb+90*, so I went to 60ftlb and called it good (still it wasn't quite equivalent to 90*) I used lube as well, and tightened in sequence.

Two things I ran into that I was a little confused about. When torque'ing the rockers the valves that should be closed started to open, I could see the spring depress a significant amount. I put my old rockers and pushrods back on just to see, and they did the same thing. A little confused about that, must have something to do with the lifters because I didn't see them compress

And my felpro gasket kit came with 6 upper intake manifold gaskets, and only 3 is used, Im not sure what the other 3 are for. Makes ya wonder when you have leftover stuff.

Appreciate the help 'Empty
 






That's a mystery to me...if the pushrods were
fully seated in the lifters and rockers, there
shouldn't be a problem...???

Don't know about the extra gaskets either; you're
right only 3 are needed.

Good luck on the start-up, let us know how it runs.
:thumbsup:
 






Well it fired up no problems, no visible leaks, I did break the damn plastic drain screw off inside the radiator, goin to have to figure that one out.

And I just went out and checked coolant level and its down 2-3 inches just as before... It was topped off before going to work, I'm praying its just air bubbles getting out of the system!
 






So how's it running, Warrant?

Did the coolant level stabilize?
 






Looks like it has stabilized. I am still a little worried though because when I get out I can still smell antifreeze burning (its not out the exhaust) so hopefully that's just residual from before.

The other thing is it doesn't seem to be holding pressure in the system, after up to temperature and its been running for a while, I can squeeze the upper radiator hose and there is no pressure at all in the system. Makes me wonder if there is still a leak somewhere.

When its warmed up there should be pressure in the system right? Its been very cold here and has been above freezing for weeks, not sure if that would effect this. Ill keep an eye on it and check oil closely on the next change.
 






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