Gasket Questions

I am not sure about the head gasket sealer, I don't use any and didn't on mine and two others and they all run good.

Is there any reason you need to change the intake or exhaust manifold gaskets? I sure don't bother removing them just to pull off a head. I only undo the exhaust pipe and the linkages and lift it all off together.

I have only seen the one piece gaskets though.

I use RTV 'ultra' or sensor safe silicone and put a skim on both sides of the cork after making the cover and edge of head spotless first. Really spotless. I am leak free. The cork does weep enough to be damp like it should, but no drips or runs. One big trick is to let it set for the 24 hours it calls for a cure before breathing on the crap.

Mike

Joe and Joann wrote:

I also have a 93 yj with the 4.0 with a noisy lifter, my question is: will the lifters come out without removing the cylinder head? My factory manual claims it can be done both ways, true??

What kind of noise does a "noisy lifter" make? I'm curious because my '02 TJ

/Peter

Mine has been making intermittant lifter noises for 100K miles. I just left it alone. It passes smog. KH

It makes a tapping/clicking noise. A valve only opens once every second engine stroke so a valve tap is slower than say piston slap which happens every stroke. If you put a timing light on, the valve will tap every second flash.

Some of those 4.0 engines do suffer from the occasional piston slap when cold. This won't hurt anything and cannot be repaired without a total engine job.

Mike

Peter P>

Ok, thanks. It's not a 'when cold' thing though - if anything it happens more when the engine is warm than when it is cold. The sound seems to occur about four or five times per second when idling at 500 RPM, which makes it 1 sound per 2 rotations of the crank. So, more likely a valvetrain thing than piston slap, right?

Can much harm come from ignoring it?

/Peter

consistently

A noisy valve normally won't hurt anything. If it gets worse, it needs attention.

Mike

Peter P>

Yes, "knock" is a pretty good description of the sound. I can feel it in the pedals too, not just hear it. This is not the NV3550 tranny noise by the way, this definitely comes from the engine.

/Peter

/Peter

Will do if I ever get a chance. The trouble being the intermittent nature of the problem. It won't do it if I'm ready for it with a stethoscope in hand or mechanic nearby. It's usually a stoplight at a busy intersection or something like that where it crops up.

/Peter

Mike Romain did pass the time by typing:

An exhaust leak back at #6 will also sound quite a bit like a lifter ticking. Best method for determining the noise source is a mechanics stethoscope.

That's typical of lifter noise. BAD on cold start_up ... goes away when oil pressure surges ..... then re_establishes when oil temp comes up and viscosity goes down.