Jump to content

Running Rough, Spark Plug Oil Fouled, Smoke Pouring From Spark Plug Hole


Recommended Posts

Guys, I need your help badly.

 

Background info.:  1988 Cherokee, 4.7L stroker with HO head (6130 casting), engine has less than 5k miles on it and is just over a year old.

 

Was heading to work the other day on my XJ and the engine started to misfire and go nuts.  Turned back around and hopped into my MJ.  Anyway, I've been trying to diagnose it tonight.  I started with the fuel injectors.  They're all fine.  Checked my dizzy and wires, they're fine (just got all new stuff about two weeks ago). Pulled my spark plugs, all fine EXCEPT the one in cylinder #2.  It was fouled with oil.  Cleaned it off, started it and let if run a minute or two.  Pulled that plug again, fouled with oil again.  However, I noticed this time when I pulled the plug, smoke starting pouring out of the plug hole.  I don't think it was burning oil, as it was not blue in color nor did it smell like burnt oil.  Suppose it could be gas, but didn't really smell like that either.  Anyway, the PCV elbow has some frothy looking oil inside.  I haven't pulled the valve cover yet, but will likely do that soon.

 

My fear is that the piston rings are FUBARed.  I'd like to add that with the engine running, it seems to have a noticeable clanking noise.  Has been doing this for a few weeks now, but I didn't think much of it because the XJ makes lots of strange noises under the hood.  Going to rent a compression tester tomorrow from the parts store and check that.

 

Anyone have any ideas of what might be going on?  If this engine is already FUBARed, I'm going to be pissed. :headpop:

Link to comment
Share on other sites

Get that compression checked. really help a diagnosis. Just off hand I think a broken ring or valve stem seal

 

That's what I was afraid of... But I will test compression and report back here.  I am not looking forward to having to tear into this essentially new engine...

Link to comment
Share on other sites

I'm with Jim on the comp test. I ran into a similar issue on my ZJ's stroker when I first built it and thought bigger was always better. Having said that... What are the specs on your cam? i went with a ridiculously large grind from Comp Cams and made one of my springs bind. Luckily, nothing got seriously damaged. Hopefully, that's what you're seeing with yours.

Link to comment
Share on other sites

Honestly, the guy who built it never gave me a build sheet, despite several requests to obtain one... Anyway, honestly, I think it's just a factory cam.  I know for sure it's got a 4.2 crank and obviously the connecting rods are longer, but I'm beginning to doubt anything else was done to internally... I know it's got OEM pistons.  It really doesn't seem to have much more power than my former stock '96 XJ...  Just guzzles more gas lol.

Link to comment
Share on other sites

Results to my compression test... Each cylinder was tested in the same manner to rule out user error:

 

 

I know cylinder 2 is messed up and reason being is because there is coolant shooting out when the plugs were all removed and engine being turned over... so, what does that mean?  Head gasket?  Cracked cylinder wall?  Something else?  :wall: :headpop:

Link to comment
Share on other sites

Results to my compression test... Each cylinder was tested in the same manner to rule out user error:

 

 

I know cylinder 2 is messed up and reason being is because there is coolant shooting out when the plugs were all removed and engine being turned over... so, what does that mean?  Head gasket?  Cracked cylinder wall?  Something else?  :wall: :headpop:

 

 

One or the other......sorry man.

Link to comment
Share on other sites

Fak. :-\ Sorry, man. Do you know how much overbore is built into your stroker?

 

Not a clue... the guy who built it has been contacted and claims he will be at my house sometime tomorrow afternoon.  We will discuss everything, include options to make this right, in vast detail.  I'm not getting bent over a barrel on this.  The long block was $1850 and with the rest of everything I did to modify and upgrade it to work in my Renix, it brought costs up to about the $3200 range.  That's no drop in the bucket...

Link to comment
Share on other sites

Not yet.  He never showed up on Sunday.  Tried all day to get a hold of him to no avail.  Finally, after blantantly asking him through text if he was avoiding my calls and texts, he replied back saying that he just opened up another shop in Dallas.  Said he was between the two at the moment and has been tied up.  Although, in reality, how hard is it to text back real quick to say you couldn't be at my place because you got stuck in Dallas?  Oh well, he said he'd be here Friday.  We'll see....

Link to comment
Share on other sites

When you pull the head, if you haven't already, try to be careful and not tear up the head gasket. After getting the head off check the gasket for signs of it leaking. If the gasket was leaking, hopefully the block and head well be OK. If the gasket was good then you have either a cracked block or head. It is possible when the cylinders was bored they punched thru on No two. Only a visible inspection will show this. If it is a small enough crack, it will be invisible to the naked eye, making it necessary to magna flux the block and head. I once had a block I suspected was cracked but I could find no trace of one. Magna flux was un availble to me at the time. I closed of the top of the block with a piece of plexi glass and with the block in the horse water trough applied air pressure to the block. The air bubbles showed exactly where the crack was. Good luck guy. Hope you get it going.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...