Exhaust header, steam clean and Kroil
I thought I'd pass along my experience with some subjects that are commonly discussed on here.
Today I replaced a cracked header with a new aftermarket unit. Before doing that, I bought a can of aero kroil and hit every fastener that needed to be wrenched. I also ran 32 oz of water through the throttle body over the weekend to chase the carbon.
The job took 3 hours. The bolts and nuts released incredibly easy for a 1998 from the rust belt. The intake ports were amazingly free of carbon deposits. Actually saw some new looking surfaces.
It's no hype what the water does to clean up your combustion chambers. And kroil is certainly a better alternative to pb blaster. That's going on my solvent shelf from now on.
Today I replaced a cracked header with a new aftermarket unit. Before doing that, I bought a can of aero kroil and hit every fastener that needed to be wrenched. I also ran 32 oz of water through the throttle body over the weekend to chase the carbon.
The job took 3 hours. The bolts and nuts released incredibly easy for a 1998 from the rust belt. The intake ports were amazingly free of carbon deposits. Actually saw some new looking surfaces.
It's no hype what the water does to clean up your combustion chambers. And kroil is certainly a better alternative to pb blaster. That's going on my solvent shelf from now on.
I wasn't sure if it was as good as the legend suggested. But after using it, I will not go back to the minor league products. It's a little expensive, but when it saves your *** in breaking loose fasteners, it's worth it.
I noticed the same phenomenon when I pulled the manifolds off of my xj for the first time. after breaking the bolts loose with a wrench I was able to use my fingers to remove them. I was very surprised given all of the rust and crud on the engine.
how exactly does one get carbon deposits on the INTAKE ports...?
how exactly does one get carbon deposits on the INTAKE ports...?
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Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I noticed the same phenomenon when I pulled the manifolds off of my xj for the first time. after breaking the bolts loose with a wrench I was able to use my fingers to remove them. I was very surprised given all of the rust and crud on the engine.
how exactly does one get carbon deposits on the INTAKE ports...?
how exactly does one get carbon deposits on the INTAKE ports...?
Seen it a million times.
Open your throttle butterfly and shine a light down there.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Once you use Kroil, you'll throw rocks at PB Blaster.
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CF Veteran
Joined: Mar 2012
Posts: 1,024
Likes: 2
From: Quebec
Year: 1996
Model: Cherokee
Engine: 4.0L
why kroil over pb blaster? not that i don't trust you, but pb blaster is readily available over the counter whereas i'd have to order kroil online at 4x the price on amazon, so is it worth it that much?
can i make my own acetone/atf mix to have comparable results?
can i make my own acetone/atf mix to have comparable results?
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
How often you need to buy it?
With Kroil, you'll use way less to get the job done.
Do you like drilling out studs instead just to save a few bucks on penetrating oil?
This is called VALUE. It's not always price.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Let's not go overboard here. It's a black baked on substance in the intake for crying out loud!!!
It gets cleaned out to a great extent when doing the water trick.
It's just fine to leave it there......
And, carbon takes on many forms.
It gets cleaned out to a great extent when doing the water trick.
It's just fine to leave it there......
And, carbon takes on many forms.
oh...right. 
for anyone interested - installing a catch can in line between the valve cover and intake manifold will keep all that oil from caking itself on the intake runners and throttle body. it does require a bit of maintenance as in occasionally emptying the can.

for anyone interested - installing a catch can in line between the valve cover and intake manifold will keep all that oil from caking itself on the intake runners and throttle body. it does require a bit of maintenance as in occasionally emptying the can.
CF Veteran
Joined: Mar 2012
Posts: 1,024
Likes: 2
From: Quebec
Year: 1996
Model: Cherokee
Engine: 4.0L
i'll try my luck with an acetone/atf homebrew mix. at the junkyard i was able to get every bolt and one of the 2 stud out and only pb blasted once 10 minutes before starting the job.
CF Veteran
Joined: Dec 2015
Posts: 2,139
Likes: 93
From: Syracuse, NY
Year: 1996
Model: Cherokee (XJ)
Engine: 4.0L
I buy Kroil on amazon, and I don't think I've ever paid anything near $50. I do buy the smaller aerosol cans, and my first can lasted over a year, and I use it on almost every job. So the value has been really good. In fact, the original can was getting low on propellant but still had product in it, so I gave it to a friend, because while it does not spray as strongly, it will still be good for probably 50-100 uses.
Once trying Kroil, I don't think I could go back to the others. It is wickedly good. I first got turned onto it when getting prepared to remove the crank pulley bolt from a honda before timing/water pump job. I haven't been without it since.
Its primary advantage is it can get into impossibly small spaces, and rather quickly. For example, extremely tight u-joints. Or seriously old and corroded fasteners.
Once trying Kroil, I don't think I could go back to the others. It is wickedly good. I first got turned onto it when getting prepared to remove the crank pulley bolt from a honda before timing/water pump job. I haven't been without it since.
Its primary advantage is it can get into impossibly small spaces, and rather quickly. For example, extremely tight u-joints. Or seriously old and corroded fasteners.







