Topic: Noise

[aka-justin]

I don't know what this is. Iginition / Fuel / or Valvetrain? It's been doing this and getting worse. Seems to be non-existant after warming up, but almost always when it's cold. My feeling is a non-pumped up lifter. I've changed the oil recently too. The strangest thing is how it suddenly goes away then creeps back.

<a href="http://www.youtube.com/v/YxZdwrphad0?version=3&amp;amp;hl=en_US" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/v/YxZdwrphad0?version=3&amp;amp;hl=en_US</a>

[sharpxmen]

i hear 2 distinct noises there, 1 i believe it is a lifter (higher pitch) unless it's one of the exhaust manifold runners either a bolt or a crack and that would explain the low pitch noise as well (you can hear both high/low in that case as when different cylinders are in the exhaust cycle).

[aka-justin]

I do have a small exhaust leak at the cat. Would a compression test confirm the lifter?

[sharpxmen]

I do have a small exhaust leak at the cat. Would a compression test confirm the lifter?

i don't think so, the valve would still open and close

[aka-justin]

Ok, thank you. This will be my next immediate project.

[Jeffy]

The puffing noise sounds like an exhaust leak at the manifold maybe.  The tap could be lifters but I'd say that's normal.

[grumpygy]

The puffing noise sounds like an exhaust leak at the manifold maybe.  The tap could be lifters but I'd say that's normal.

I didn't answer cause I was thinking nthats the way mine sounds and its running good.

[neale_rs]

Normal for the 2.5 but maybe not for the 4.0.  I used to have a 4.0 in a '96 Grand Cherokee and it did not sound like the 2.5. 

[dwtaylorpdx]

Back when I had the stock exhaust manifold ,, mine got a nasty metalic noise,
When I put the header on I found a 1/2 inch hole on the back side of the
manifold just above the collector... It had cracked and a piece fell out..

Dave

[aka-justin]

Tomorrow is D-Day. New lifters arrived yesterday alongside of head gasket, assembly lube, and break in oil additive. I also picked up oil, filter, coolant, head bolts, and spark plugs. I scored a new valve cover gasket and lightly used ignition coil pack for $75 too (busted a pin last spark plug change and shoved it back in, so been meaning to replace it.)

I'm going deep into the unknown so I'll post an update as I progress. Kinda of throwing everything at this - I hate hearing the noise at only 66k. We'll see how bad... I mean... good I do...  

UPDATE: I RTFM and saw I should have picked up a intake/exhaust gasket. I'll have the wifey do that later in the day.

[dwtaylorpdx]

Use a shop vac to suck the water out of the cooling jacket before
you pop the head loose and after to get it out around the sides of
the block. Use a shop vac constantly while cleaning the top of the block.

I put assembly lube on the cylinder walls and a bead around the tops
of the pistons to keep stuff from getting down there while you clean
the top of the block.

Spray gasket remove (Nasty stuff) is good for cleaning the top of the block.
I always take the head to a shop and have it boiled out and I put new valve
seals in and new springs. (Springs are cheap and they lose a bunch of their
"spring" after 50K miles.)

Chase the head bolt holes with a tap before install.

If the head has many miles at all, a good 3 cut valve job is a good investment.

Dave

[aka-justin]

I always take the head to a shop and have it boiled out and I put new valve
seals in and new springs. (Springs are cheap and they lose a bunch of their
"spring" after 50K miles.)

At 66k miles? I'm a little heasitant. If it was 100k+ I'd be game. How much has it run you to get it done?

[sharpxmen]

you're not taking the head off just to replace the lifters?  a $5 magnetic pickup will do the trick just fine and save you about 4 hours of work. I can only hope you're reading this before starting the work in case that's the only reason you plan to do it.

[aka-justin]

you're not taking the head off just to replace the lifters?   a $5 magnetic pickup will do the trick just fine and save you about 4 hours of work. I can only hope you're reading this before starting the work in case that's the only reason you plan to do it.

4.0L supposidly have to take the head off. Look at this 2001 head - the castings are too small to pull the lifters out.  I've also read through the FSM.

[sharpxmen]

4.0L supposidly have to take the head off. Look at this 2001 head - the castings are too small to pull the lifters out.  I've also read throught the FSM.

god, looks like you're right - that's completely retarded. I guess you don't have a choice. The head does look different than the older ones, they are machining the valve cover gasket seat on it which was just raw casting before. downside are the smaller pushrod holes, darn