Important

The intake plenum gasket is the gasket that seals the thin sheetmetal cover over the hole on the underside of the intake manifold where it covers the lifter valley. The plenum cover is thin stamped sheetmetal from the factory so the gasket likes to sag out and suck up oily air from the crankcase, they blow out often and there is an aftermarket kit out there that stiffens up or replaces the stock cover so that the gasket doesn't pop out or lose seal anymore. Iirc the kit including all needed gaskets is 140 or so.

so its the intake gasket?

mac 'readers digest' gyvr
 
In the past when I have dealt with blown head gaskets the oil was frothy and the vehicle was blowing white smoke out of the tailpipe.

I checked the oil. It does not appear to be frothy and doesn't appear to be brand new...it definitely needs changed. I also followed Chaz as he drove it across town for me. There was nothing that came out of the tailpipe. So I'm hopeful a flush will fix...will do that this week.

Also I could smell antifreeze when it was running...but I didn't see any on the ground or anywhere.

I'll have to do some more checking when I flush it.

I want to flush it and get it to the trans shop this week.

mac 'ready to start racing around town in it' gyvr

Like Josh said with the 6.0, the head gasket was cracked on my Subaru to where the hot air from the exhaust side was blowing into the coolant passages and superheating the coolant. There are ways the headgasket can fail without having frothy oil, That's just the most common sign in Jeeps.

Flexd'I'm sure you know most of that'XJ
 
It's not the intake gasket. The bottom of the intake manifold is removable for reasons I don't know. But because of that it has a gasket that tends to leak
 
It's not the intake gasket. The bottom of the intake manifold is removable for reasons I don't know. But because of that it has a gasket that tends to leak

so to get to it you have to pull the intake? and replace the intake gasket?

how would one check to see if this is bad?

Is everyone running these 5.9s always putting premium fuel in them? I know that they call for it...but...

mac 'research' gyvr
 
Keep a eye on oil level and look for smoke under acceleration. Spark plug knock is another indication of plenum gasket leak. Intake would come off and intake gaskets would need replaced too.

The 98 needs premium because of the tune on the PCM it advances the timing so if lower grade fuel is used it will ping and tick. A SCT tuner from hemifever tuning can fix it to run on lower octane and make the jeep wake up quite a bit!
 
so to get to it you have to pull the intake? and replace the intake gasket?

how would one check to see if this is bad?

Is everyone running these 5.9s always putting premium fuel in them? I know that they call for it...but...

mac 'research' gyvr

Google Fu

http://www.kevinsoffroad.com/techarticles/59_pingandpredet.html

Looks like some good info.

If I was going through all the trouble to take the intake off to fix that gasket, I'd put an intake on it that was gasket free.
 
You'll be putting premium in it or it will ping like a mutha. It's not a 5.9 thing. It's a Jeep 5.9 limited thing. Has to do with how they have the timing set. Performance ya know?
 
So I am looking to replace all the bearings and seals in my d44/9inch. Is there a company out there that sells a "whole" kit instead of buying them piece by piece? I have looked around and there are kits out there but not an entire axle kit unless I missed something.
 
Also, the only gadget that I have found to not work is the passenger's side seat heater, the rear wiper has issues, and the rear drivers window needs a motor or something cause the window doesn't stay up.

mac 'guessing game' gyvr


I'll have pictures on how to fix your passenger sie seat heater element next week. Assuming you hit te button and the light just flashes. Very good writeup on it @ NAGCA.

window needs new motor and regulator, the teeth are probably stripped, so it sags until it hits the next good teeth.
 
Missed that.

Curious about the write up on the seat heater as they don't work in my dads either.

if you hit the button and the "hi" light flashes it's telling you there's no continuity in the element. It seems as it's usually the wires that connect the wiring to the element. Someone at Chryco put them on the side of the seat nearest the door, so the connectors get broken/burned from asses sliding over them. You've got to pull the seat bases, pull the upholstery and solder the wires back. I plan on moving the connection and splicing stranded wire over the "corner" where they come up the seat.
 
It's not the intake gasket. The bottom of the intake manifold is removable for reasons I don't know. But because of that it has a gasket that tends to leak

I believe it is done to simplify the casting process, but not sure. Easier to chip sand/plaster out through a big hole in the bottom than it is to try and get it all from the manifold ports.

They should have simply built the plenum plate properly the first time (larger stiffening flange, or from thicker metal, or a machined aluminum piece like some of the aftermarket fix kits have) but apparently it did not fail in testing, just actual use after a few years.
 
So I am looking to replace all the bearings and seals in my d44/9inch. Is there a company out there that sells a "whole" kit instead of buying them piece by piece? I have looked around and there are kits out there but not an entire axle kit unless I missed something.

A phone call to someone who knows what they're talking about (Randy's, etc., pick your shop) will get you everything you need.

I actually got better prices on my ford stuff at Jeff's Bronco Graveyard than I did at any of the offroad shops.
 
I believe it is done to simplify the casting process, but not sure. Easier to chip sand/plaster out through a big hole in the bottom than it is to try and get it all from the manifold ports.

They should have simply built the plenum plate properly the first time (larger stiffening flange, or from thicker metal, or a machined aluminum piece like some of the aftermarket fix kits have) but apparently it did not fail in testing, just actual use after a few years.

A new style M1 or hughes air gap will be the fix on mine. No plenum gasket and a lot better flowing.
 
A phone call to someone who knows what they're talking about (Randy's, etc., pick your shop) will get you everything you need.

I actually got better prices on my ford stuff at Jeff's Bronco Graveyard than I did at any of the offroad shops.


james duff is here in knoxville...they might have all that stuff too
 
A phone call to someone who knows what they're talking about (Randy's, etc., pick your shop) will get you everything you need.

I actually got better prices on my ford stuff at Jeff's Bronco Graveyard than I did at any of the offroad shops.


Yes, I think a phone call is going to be the way to go. I checked a couple websites and they have bearing and seal kits but most of them are for ring and pinion installs, and I need EVERYTHING. :D
 
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