Steam cleaning your 4.0
 

I'm sure from time to time y'all see somebody mention steam cleaning your engine. You may wonder what that mean exactly or be skeptical of doing that, thinking it must be a joke.

Rest assured, it is not a joke at all.

Let's start with my jeep, it's a 99 XJ with 4.0 that has 150,000 miles on the clock. The engine has never been cleaned internally. To add to the description, I replaced the intake manifold at approximately 125,000 miles and I saw really thick gunk that was coated inside the intake and exhaust ports of the head.

I used my borescope to look inside the cylinders and the intake manifold & took pictures so you get the idea of what it look like before the steam cleaning.


(The scratches on the piston was caused by my camera when I put it in too far)
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This is the internal wall of the intake manifold runners where it's about to enter the intake port of the head
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This is the intake valve chamber, you can clearly see the intake valve stem here
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The procedure/method that I used is really simple.

1: remove the hose from the air filter box leading into the throttle body.

2: start the engine

3: rev up the engine to approximately 2,500 rpms and keep it there. (I used a washer in between the throttle butterfly shaft and the screw on the bottom of the throttle body).

4: slowly dribble water from a 32 ounce container (large size drink cup from a fast food establishment works well)

VERY IMPORTANT NOTE; DO NOT DUMP THE WATER ALL AT ONCE!!!!

5: when the engine bogs down & the rpms drops, ease on the water until the engine catches up then resume.

6: continue until 32 ounces of water is gone.

7: turn the engine off once the rpms catches up.

8: put the hose back on the top of the throttle body.

Here's the "after" pictures.



See how there's no black gunk or build up anywhere? It's all pure grey metal, it's like it's almost new!
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Ah one single remaining carbon spot!
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You now can see the cross hatching marks on the cylinder wall! Great success!
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See how clean the piston is?
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The conclusion. The steam cleaning method is in fact a proven method of cleaning the engine internally.

(I did this twice in half hour total with 1/2 gallon of water). A total of a gallon.

VERY IMPORTANT NOTE; DO NOT DUMP THE WATER ALL AT ONCE!!!!

Excellent post man! A good portion of us know this works already, but it's good to SEE the evidence of it working... plus for those who are leery about doing it, this can help set their minds at ease that what they're about to do is a GOOD thing.

:thumbup:

:confused1:


Wouldn't it be better to run the engine at 4000 RPM and dump the water in all at once? I mean, more is better, right?


/ducks/



:D



Excellent write up! :thumbup1:

Bet there still at least one person that dumps it in all at once, then posts "Jeep won't start after steam cleaning it!" Lol

Or uses the garden hose....

What, you're NOT supposed to use the soaker setting on the hose nozzle? :dunno:

Forget the garden hose. Take it to your local firehouse and borrow their pumper. Pressure wash them babies. Add a little sand to get them all nice and shiny.

Just kidding. DONT DO THAT! :no:

I've done a seafoam treatment but pulled the vac line off the booster. boy did that sucker smoke for a bit after the shut-down and restart. #mesquitorepellent.

I'd also like to add that the 4.0L is prone to carbon build up. If you've never done a top-end cleaning, than it's highly recommended especially higher mileage engines. To prolong carbon buildup in the future, take your XJ for a high RPM run down the highway time to time.

EDIT* notice I said high RPM run... I feel the need to correct that and mention that this does not mean high speed! Simply wind out first or second gears. You can keep the RPM's high by keeping her out of OD too.

in the old days I did this with tranny fluid...boy did it smoke but ran great after.going to try with water this time.

haha yes I was waiting for someone to mention tranny fluid! I just don't know how o2 sensors would like burnt tranny fluid passing by them which is why I didn't try it on my xj.

I've done the steam clean before. It was on my 1967 Mustang with the straight 6. Ran like a champ after that, but I havn't done it to my Jeep yet.

What would be the advantage of Trans Fluid over Water? Is there a chemical make-up that cleans better, or other type of more thorough cleaning property?

I need to try this, been using seafoam. Is seafoam worse then water would be?