Author Topic: Need Engine Help  (Read 2990 times)

storch

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« Reply #45 on: March 03, 2007, 07:24:05 AM »
Quote
Originally posted by Gunslinger
Well it seems I'm curing the symptoms and not the disease.  It's happening again.  It's not as bad as before but I think I ruined the CAT in the process cause it sounds like a bunch of marbles in a tin can.  

Now I know I have an exhaust leak that I'm fixing this weekend but it seems to have fouled up another plug.

The first cylinder isn't firing.  It comes and goes but it's here to stay now.  I'm gonna pull the plugs again tomorrow and look at them.  I think the Jeep has bested me this time and its gonna take a professional to diagnose the problem.  

anyone have any other idears?

Everything else is good.  no major leaks except the rear main.  They seem to allways go in jeeps.
how old is that jeep again?  the cat probably has a cooling sleeve that surrounds it.  sometimes the vibrations fatigue the steel that holds them about 1/2" off of the cat and the perforated steel piece is just laying atop of the cat giving you your annoying rattle.  check that first.  with the cat cool just reach above it and cop a feel.

how do you know it's not firing?  how did you test to be sure?  did you replace the dist cap rotor and wires?  pull the plug and check gap also check for fouling.

Offline mora

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« Reply #46 on: March 03, 2007, 08:36:33 AM »
If he has driven any considerable length with the engine running like it was, then the cat is most likely busted. For every percentage of CO in the exhaust gas it's operating temperature will initially raise by around 100 degrees Celcius. Even small unnoticeable misfiring or slightly rich mixture may cause damage to it, and noticeable misfiring will definately cause damage.

If you replace the cat make sure that it's intestines haven't blocked the muffler behind it.
« Last Edit: March 03, 2007, 08:41:54 AM by mora »

Offline Gunslinger

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« Reply #47 on: March 03, 2007, 09:39:27 AM »
The Jeep is a 93 but the motor is only about 5 years old.  It's a remanufactured long block.  I replaced all the plugs wires rotor and cap.  The thing ran smooth for a week and now it's doing it again.

Offline SirLoin

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« Reply #48 on: March 03, 2007, 09:56:56 AM »
Could be EGR valve..that would cause a rough idle.Engine diagnostic would find that out.
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Offline SteveBailey

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« Reply #49 on: March 03, 2007, 10:56:01 AM »
Gunslinger, another possibility is that the cat is done... plugged up.(it happens)
This is a simple test.... yank the cat and run the motor.

Offline Masherbrum

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« Reply #50 on: March 03, 2007, 10:58:42 AM »
Quote
Originally posted by Gunslinger
Well it seems I'm curing the symptoms and not the disease.  It's happening again.  It's not as bad as before but I think I ruined the CAT in the process cause it sounds like a bunch of marbles in a tin can.  

Now I know I have an exhaust leak that I'm fixing this weekend but it seems to have fouled up another plug.

The first cylinder isn't firing.  It comes and goes but it's here to stay now.  I'm gonna pull the plugs again tomorrow and look at them.  I think the Jeep has bested me this time and its gonna take a professional to diagnose the problem.  

anyone have any other idears?

Everything else is good.  no major leaks except the rear main.  They seem to allways go in jeeps.


$20 says you have a blown ring in the cylinder.    You have blow-by in the cylinder that isn't firing.

Is this a 4.0L HO or a 4.2L?   I'm guessing you have the 4.2L, and if so, this has been your culprit all along.
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Offline SteveBailey

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« Reply #51 on: March 03, 2007, 11:13:34 AM »
Quote
Originally posted by Masherbrum
$20 says you have a blown ring in the cylinder.    You have blow-by in the cylinder that isn't firing.

 



I'll take that bet.

Offline Gunslinger

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« Reply #52 on: March 03, 2007, 11:30:00 AM »
Quote
Originally posted by Masherbrum
$20 says you have a blown ring in the cylinder.    You have blow-by in the cylinder that isn't firing.

Is this a 4.0L HO or a 4.2L?   I'm guessing you have the 4.2L, and if so, this has been your culprit all along.


It's the 4.0L HO.  That link that nirvana posted has been pretty insightfull.  

Steve I don't think the cat is plugged.  I think it's a symptom and not the problem.  Either way I have my new exhaust sitting right next to me with the exception of the header.  That got lost in Dallas and ended up in mesquit, TX.

I'm just a little too hung over to do much right now.

Offline Gunslinger

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« Reply #53 on: March 03, 2007, 11:57:12 AM »
Pulled the plug on the number 1 cylinder and it's not good news for me.





EDIT:  In case you havn't read the whole thread, these are brand new  (well 2 weeks old)

So that's not oil but completly coated with a layer of carbon.
« Last Edit: March 03, 2007, 12:00:00 PM by Gunslinger »

Offline SteveBailey

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« Reply #54 on: March 03, 2007, 12:08:26 PM »
Hmmm, Well if it's limited to one cylinder, you are probably talking about a sticking valve/bad seal or maybe stuck(closed), blocked, malfunctioning injector.   What do the other plugls look like?


Of course w/ the advent of onboard computers to screw up, I mean monitor, everything that's always a possibility.

Offline Gunslinger

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« Reply #55 on: March 03, 2007, 12:29:12 PM »
I'm pulling the rest of the plugs now but it gets worse.  Here's the oil fill cap and the breather from the valve cover.



would that be coolent mixing with oil?

Offline SteveBailey

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« Reply #56 on: March 03, 2007, 12:31:09 PM »
Quote
Originally posted by Gunslinger
I'm pulling the rest of the plugs now but it gets worse.  Here's the oil fill cap and the breather from the valve cover.



would that be coolent mixing with oil?




Now you're getting somewhere.. and it's not looking good.  It looks like the fluids are mixing but I can't say for sure since I'm not there.  What does the coolant look like?

Offline john9001

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« Reply #57 on: March 03, 2007, 12:40:53 PM »
you have coolent in your oil , time for a leak down test, and compression test.

storch

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« Reply #58 on: March 03, 2007, 12:41:25 PM »
that looks like you are making oil.  maybe a head gasket maybe a cracked block.  does the starter turn over slugglishly in the morning?  what does the dipstick oil look like when you check it cold?
« Last Edit: March 03, 2007, 12:53:09 PM by storch »

Offline Gunslinger

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« Reply #59 on: March 03, 2007, 12:53:14 PM »
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Originally posted by SteveBailey
Now you're getting somewhere.. and it's not looking good.  It looks like the fluids are mixing but I can't say for sure since I'm not there.  What does the coolant look like?


The coolent looks brown and foamy