New used 04 kj, few issues

[norm6269]

Hello all, first off I absolutely love my used 2004 kj. 5 speed 3.7 is super fun to drive. Anyways the previous owner didn't keep up with maintenance so now I'm trying to bring it back to full health. I drained and replaced the coolant and noticed the rust sludge in the tank. What is the best method in cleaning it out? Tank removal or can I just run a garden hose thru it? Notice a small miss so I changed plugs and coils. Still has a miss but it is not triggering a CEL. Any thoughts? I thought a vacuum leak would get a CEL. Also it seems the engine is very loud, not complaining but is the 5 speed louder than the automatic? I was a diehard Isuzu owner but this thing is converting me. Thanks to all that have insight.

 

[profdlp]

When you did the coolant did you use HOAT anti-freeze? If you're not sure then you almost certainly did not. That is responsible for all manner of problems and since you tell us that the previous owner was not all that responsible it is probable that they did not use HOAT either.

The preferred method is to let the dealer flush it. It's one of the few things they do well and don't charge an arm and a leg for. You could also try the method in this post:

http://www.jeepkj.com/forum/f196/i-broke-my-radiator-can-fixed-57473/#post649876

When draining the radiator I would remove the lower drain plug completely and check the O-Ring. I just did mine ten days ago and needed to replace it. I bought a whole new drain plug for $9 which worked well. The reason I mention this is that the aperture for the drain is tiny and big clogs won't make it through. Taking the whole lower drain plug out allows for more crap to get out of the radiator. The plug itself is easy to remove. Once you've loosened it just keep backing it out until it's wobbling around, then pull. Thanks to Itd02 for confirming this. (See post #39 here: http://www.jeepkj.com/forum/f196/water-pumps-n00bs-57502/ ).

I just flushed my cooling system and followed the advice I've just given you. I plan to do it again in a few months to give it another thorough cleaning. Like you, I bought mine used and can't really be sure what the previous owner had done to it. One thing I have learned here is that you do not want to overheat these 3.7L engines. A couple gallons of HOAT several times through to purge any non-compliant coolant is cheap insurance.

 

[tommudd]

3.7s are a little noisy to some
Radiator needs a good power flush if there is a lot of junk in there. Then new hoses/ thermostat etc and be good on cooling with approved coolant
What plugs did you go with? Only copper core NGK/ Champion none of the " designer type" plugs
If not much has been done then front and rear diff changes are needed , just use plain old dino oil
Transfer case as well of course
If you want to see how much its sagged ( KJs have very weak springs and shocks from the factory) . Measure from middle of the wheel to bottom of the flare in front, would of been 19-19.25 brand new.
There is a good nights work for you to start spending quality time with her. :icon_lol:

 

[twowings]

I know what you mean....I love my '04 3.7L 5-speed too! Previous owner was well-to-do wife (but probably not a mom or grandma since interior is spotless LOL) who had all regular maintainence performed and put about 8,000 miles/year on it....undercarriage is spotless so must have been garaged/washed regularly...hope you continue to enjoy yours for years to come!

 

[norm6269]

Thanks all, I will use the advice and flush out...I used Champion plugs. Also will do the diff fluid swaps and probably replace the rear shocks, they do make a bit of noise

 

[norm6269]

Flushed the radiator 2 times, filled with HOAT. Lots of gunk but it blows some hotter air now. Any recommendations on rear diff oil and shocks?

 

[tommudd]

Flushed the radiator 2 times, filled with HOAT. Lots of gunk but it blows some hotter air now. Any recommendations on rear diff oil and shocks?

2 wheel drive ? if 4 wheel drive better do front and rear diffs . Just use regular dino, no synthetic . Do you tow anything on a regular basis if so weight of oil would be different
As far as shocks go, unless replacing springs as well, going to be a waste since the sagged springs will over work the new shocks and wear them out faster . New springs better ride and handling

 

[norm6269]

Just 2wd. No towing either. Ok so will replace shocks and springs, I guess non OEM would be the best idea going forward?

 

[ElCheapo]

Hello all, first off I absolutely love my used 2004 kj. 5 speed 3.7 is super fun to drive. Notice a small miss so I changed plugs and coils. Still has a miss but it is not triggering a CEL. Any thoughts? I thought a vacuum leak would get a CEL. Also it seems the engine is very loud, not complaining but is the 5 speed louder than the automatic? I was a diehard Isuzu owner but this thing is converting me. Thanks to all that have insight.

Check plug wires, they might need replaced.
Vacuum leak won't throw a CEL, as it's a mechanical issue. CEL is only for issues that can be detected in the electronic system by the 'puter. You may get a code for some type of air/fuel issue, which you will need to determine the cause.



Also, thanks tommudd, I was wondering how to check my springs for sagging.

 

[libertybob]

Small miss?

A miss can be caused by the 3.7L throwing a rocker arm off a valve. Would be a consistent miss on one cylinder and is usually accompanied by very rough running. You can Google this problem. Not likely your problem if it is an intermittent small miss, but mention it just in case you can't find another reason.

 

[tommudd]

Check plug wires, they might need replaced.
Vacuum leak won't throw a CEL, as it's a mechanical issue. CEL is only for issues that can be detected in the electronic system by the 'puter. You may get a code for some type of air/fuel issue, which you will need to determine the cause.



Also, thanks tommudd, I was wondering how to check my springs for sagging.

Well if its over 6 months old and over 2000 miles then they need replacing!:happy175:
Seriously KJs came with really crappy weak springs and weak shocks. At 20,000 miles I had already swapped mine out since it would bottom out on smooth RR crossings. General rule of thumb is 50-60,000 miles replace at least shocks but with our weak springs both need upgraded
So now in front measure middle of the wheel to bottom edge of the flare ( measure left side since it normally settles/ sags more than the right side
If built before April 12,2002 then it would of been 19.75-20 , if after that date then 19.19.25 we normally just round to 19.
I've had them in my garage with 75,000 miles and sitting over 1.50-1.75 inches lower than new stock. Owner was wondering what the noise was , bumpstops were gone :icon_lol:

 

[ElCheapo]

Well if its over 6 months old and over 2000 miles then they need replacing!:happy175:
Seriously KJs came with really crappy weak springs and weak shocks. At 20,000 miles I had already swapped mine out since it would bottom out on smooth RR crossings. General rule of thumb is 50-60,000 miles replace at least shocks but with our weak springs both need upgraded
So now in front measure middle of the wheel to bottom edge of the flare ( measure left side since it normally settles/ sags more than the right side
If built before April 12,2002 then it would of been 19.75-20 , if after that date then 19.19.25 we normally just round to 19.
I've had them in my garage with 75,000 miles and sitting over 1.50-1.75 inches lower than new stock. Owner was wondering what the noise was , bumpstops were gone :icon_lol:

Didn't mean to derail the thread, but I'll check them when I leave for work today. Is any brand preferred, or just get Monroe?

 

[tommudd]

Didn't mean to derail the thread, but I'll check them when I leave for work today. Is any brand preferred, or just get Monroe?

If you want to upgrade then OME or Ironman, if you want cheap and need replacing in another 50,000 then monroes and stock springs
But I hate , no wait really hate the ride of a stock KJ compared to aftermarket springs and shocks, handles and rides so much better
Mine with 213,000 and aftermarket springs and shocks rides 100 times better than my Stepfathers with 80,000 miles and it was a one owner babied KJ when I picked it up for him

 

[norm6269]

I already replaced the coil packs, I'll hunt for a vacuum leak, thanks

 

[Leeann]

Check plug wires, they might need replaced

What plug wires??

 

[tommudd]

What plug wires??

Oh so you have missed those have you ?
Ya really have to look close to find them :icon_lol::gr_grin:

 

[ElCheapo]

Am I missing something? Doesn't the 3.7 have plug wires?:shrug:







My liberty measures 18.5" from center of wheel to outer edge of fender flare.

 

[nullptr]

Am I missing something? Doesn't the 3.7 have plug wires?:shrug:

Nope, it has coil on plug. I mean, there are wires running to the coils, but they aren't plug wires in the traditional sense and are really part of the engine wiring harness.

The 2.4 has wires?

 

[tommudd]

Am I missing something? Doesn't the 3.7 have plug wires?:shrug:







My liberty measures 18.5" from center of wheel to outer edge of fender flare.

the 4 cylinder does have plug wires, the 6 does not
you're 1/2 to 3/4 of an inch lower

 

[ElCheapo]

the 4 cylinder does have plug wires, the 6 does not
you're 1/2 to 3/4 of an inch lower

Correct, about 6" long replaceable plug wires.

How low before the springs need replaced?