Disgusting spark plugs from my "new" CJ7

[AKR]

When I bought this CJ7 about 5 weeks ago, they said "The motor was just rebuilt!" Stupidly, I believed him. I should have taken one of the plugs out and said "Really, you guys are lying." Well today I took out the plugs and this is what they all look like. The second plug in from the right I cleaned with a brush, but it looked as bad or worse than the rest.
But compression tests show: 150psi to 140psi.

 

[mtnwhlr]

But compression tests show: 150psi to 140psi.

So you have good compression by the way the plugs look I think you have worn valve guides. I wonder if they just did the bottem end and didn't do anyting to the head.

 

[tarry99]

When I bought this CJ7 about 5 weeks ago, they said "The motor was just rebuilt!" Stupidly, I believed him. I should have taken one of the plugs out and said "Really, you guys are lying." Well today I took out the plugs and this is what they all look like. The second plug in from the right I cleaned with a brush, but it looked as bad or worse than the rest.
But compression tests show: 150psi to 140psi.

Disgusting.................Yep to say the least.

If it was all oil they would be black......Look for contaminated fuel, overheating, to lean & perhaps pre ignition.

They said the motor was just rebuilt? When? ......20 years ago!

I would drain and flush the fuel tank, change the filter, check the timing, run a pressure check on your cooling system to see if you have a head gasket issue or leak .............then put a new set of plugs in there and run it for a while and then check again.

 

[Les]

Yep, I'm thinking mtnwhlr might be right. If the engine was recently rebuilt, and your compression is good, they might have just re-faced the valves during the rebuild and the valve guides might indeed be leaking. Most people would tend to assume an oil leak would create black, sooty plugs, which would be the case with leaky rings. However, when you get a leaky valve guide, the amount of oil tends to be much less, so it gets flash cooked in the cylinder and leaves whitish deposits behind on the plugs which consist of calcium, sulfur, zinc, etc.. The fact that they are white and crusty, instead of just white, would seem to rule out the possibility of a overheat or lean condition.

One easy way to check for leaks, would be for someone to follow you as you drive the Jeep. Step on the accelerator, get the engine up to a fairly high rpm, then take your foot off the pedal and coast. Have the person following watch your exhaust pipe and if they see a puff or two of smoke, then the engine is sucking oil around one or more of the valve guides.

If this is the case, all is not lost, because you can probably have the valve guides knurled to eliminate the problem. If I remember correctly, it can correct a guide that is up to .006 out of spec. At least, that's what I remember from using the kits from Hastings, back in the day.

 

[IOPort51]

AMC 258 i6 / 4.2l heads like to crack between the valves, I have never had one foul at more than two cylinders. And it does not show up with compression test, just fouled plugs. replace them and check them every 100 miles to get an idea of how big a problem you have.

 

[AKR]

I did put in new plugs today and ran it for a few hours. It really idles nice and smooth now. Before it was missing pretty bad. Also, I was out Saturday (before I replaced the plugs) and I stopped and let it idle. While looking at the exhaust, there was a lot of blue smoke...
Also, when I put in the new plugs, the #1 cylinder started "ticking". I added more oil and that made it stop. But also there was a lot of black water spots coming out of the exhaust just a few minutes after I put in the new plugs. I think that the #1 cylinder was not firing at all.
The carburetor is the Weber 32/36 DGAV. The guys were really excited about "how much better it was than stock" , but I think it runs too lean. I doubt they even had it tuned up correctly.

They were those guys who had the attitude "Just throw on whatever, it'll be cool."

 

[Les]

I did put in new plugs today and ran it for a few hours. It really idles nice and smooth now. Before it was missing pretty bad. Also, I was out Saturday (before I replaced the plugs) and I stopped and let it idle. While looking at the exhaust, there was a lot of blue smoke...
Also, when I put in the new plugs, the #1 cylinder started "ticking". I added more oil and that made it stop. But also there was a lot of black water spots coming out of the exhaust just a few minutes after I put in the new plugs. I think that the #1 cylinder was not firing at all.
The carburetor is the Weber 32/36 DGAV. The guys were really excited about "how much better it was than stock" , but I think it runs too lean. I doubt they even had it tuned up correctly.

They were those guys who had the attitude "Just throw on whatever, it'll be cool."

Uh oh, it's starting to sound more and more like you do have head issues. While I previously posted that you may have valve guide problems, IO was saying you might have cracking between valves. I just had a thought that both possibilities might be accurate, because I have seen something like this in the past. I ran across another AMC 258 i6 / 4.2l several years ago that had been partially oil starved, from a malfunctioning oil pump. The primary parts of the engine that were damaged were up in the top end, where the valve guides and rocker arms got scored, as well as cracking being detected during a magnaflux after the tear down......But, in your case, I really hope I'm totally wrong on this. However, it might have been the event that caused the engine to be torn down for rebuild in the first place?

Also, if you have a Weber carb that is running lean, you probably have the only one on the planet that has that problem. Every single one of those I've seen, always seem to have to be re-jetted because they run rich....lol......I finally junked mine and went to the MC2150 carb awhile back. I literally tried every single mechanical procedure I knew to make it function properly.......adjusting....re-adjusting...re-re-adjusting..re-jetting.....re-sealing......yelling.....cussing.....throwing things.....etc.....nothing worked...lol

 

[AKR]

Uh oh, it's starting to sound more and more like you do have head issues. While I previously posted that you may have valve guide problems, IO was saying you might have cracking between valves. I just had a thought that both possibilities might be accurate, because I have seen something like this in the past. I ran across another AMC 258 i6 / 4.2l several years ago that had been partially oil starved, from a malfunctioning oil pump. The primary parts of the engine that were damaged were up in the top end, where the valve guides and rocker arms got scored, as well as cracking being detected during a magnaflux after the tear down......But, in your case, I really hope I'm totally wrong on this. However, it might have been the event that caused the engine to be torn down for rebuild in the first place?

Also, if you have a Weber carb that is running lean, you probably have the only one on the planet that has that problem. Every single one of those I've seen, always seem to have to be re-jetted because they run rich....lol......I finally junked mine and went to the MC2150 carb awhile back. I literally tried every single mechanical procedure I knew to make it function properly.......adjusting....re-adjusting...re-re-adjusting..re-jetting.....re-sealing......yelling.....cussing.....throwing things.....etc.....nothing worked...lol

I forgot to mention that the oil pressure is all over the place as well. Idle is 18 psi, cruise is 15, then up to 40. Sometimes back to 18psi. Revving at idle it won't go past 25psi, and tries to go up when I let off the gas and down when I accelerate. (Gauge is brand new as is sending unit)

 

[Les]

I forgot to mention that the oil pressure is all over the place as well. Idle is 18 psi, cruise is 15, then up to 40. Sometimes back to 18psi. Revving at idle it won't go past 25psi, and tries to go up when I let off the gas and down when I accelerate. (Gauge is brand new as is sending unit)

While the oil pressure gauge in a CJ tends to jump around a bit, because it does not have the electronic dampening that modern cars have, some of the oil pressure numbers you mentioned do seem a little low. As a reference, I rebuilt my AMC 258 i6 / 4.2l about 20k miles ago, and on a hot, Summer day, I get 40+psi on startup, then once it is warmed up, I get anywhere from 30-40psi, depending upon RPM.

So, in addition to your spark plug issues and if your gauge is working properly, you may have oil bypassing internally somewhere inside the engine. This is also assuming that there is nothing wrong with the oil pump itself. I'm starting to not like the guy that rebuilt your engine.

 

[AKR]

While the oil pressure gauge in a CJ tends to jump around a bit, because it does not have the electronic dampening that modern cars have, some of the oil pressure numbers you mentioned do seem a little low. As a reference, I rebuilt my AMC 258 i6 / 4.2l about 20k miles ago, and on a hot, Summer day, I get 40+psi on startup, then once it is warmed up, I get anywhere from 30-40psi, depending upon RPM.

So, in addition to your spark plug issues and if your gauge is working properly, you may have oil bypassing internally somewhere inside the engine. This is also assuming that there is nothing wrong with the oil pump itself. I'm starting to not like the guy that rebuilt your engine.

Yah , maybe I should transplant with a new V8 now...

 

[rocmoc]

Don't feel too bad, you are not by yourself. I got burned by a nice little older couple, mid-70s, saying the Transfer Case had be rebuilt, NOT! And that was only the start, Hang in there!

rocmoc n AZ/Mexico

 

[Les]

If, your engine does prove to have big issues other than just needing work on, or replacement of the head, upgrading is always an option, but will cost quite a bit. However, if you want to avoid extra expense, you could just drop in a rebuilt. For instance, I know several people that have installed an exchange engine from ATK. They are available from several of the 4x4 sites, including quadratec. Here is the link:

http://www.quadratec.com/products/51107_0001.htm

The cost of the engine (long block assembly) is about $2k (less the core charge), with the core only having to be the same kind of engine, no visible damage and having the ability to turn over when you give it to them. It comes with all the gaskets and you just have to swap over your accessories onto it, such as the starter, alternator, carb, etc.. The warranty on the engine is 3yr/unlimited miles.

Here's hoping all that I just said won't be needed though.

 

[tarry99]

I did put in new plugs today and ran it for a few hours. It really idles nice and smooth now. Before it was missing pretty bad. Also, I was out Saturday (before I replaced the plugs) and I stopped and let it idle. While looking at the exhaust, there was a lot of blue smoke...
Also, when I put in the new plugs, the #1 cylinder started "ticking". I added more oil and that made it stop. But also there was a lot of black water spots coming out of the exhaust just a few minutes after I put in the new plugs. I think that the #1 cylinder was not firing at all.
The carburetor is the Weber 32/36 DGAV. The guys were really excited about "how much better it was than stock" , but I think it runs too lean. I doubt they even had it tuned up correctly.

They were those guys who had the attitude "Just throw on whatever, it'll be cool."

AKR
Well it sure looks like there is other issues...........black spots is normally carbon which sometimes tells you the combustion cycle is being mixed with water ( head gasket or cracked head ) and the resulting super heated water is steam cleaning the carbon off the pistons which in up in your exhaust.
Variable oil pressure @ variable rpm's could be several issues but most of the time look to rod or main bearings being warn.
If you do not have the ability to check these issues out take it to a reputable mechanic in your area for an opinion. Rebuilding what you have is always an option.............

 

[AKR]

As far as the oil/water/black "spewage". the only time this happened was after I put in the new plugs. I think that one of the cylinders was not firing at all and then when I put the plugs in, it started firing.So there could have been a build up of moisture in there. Because now the oil/water "spewage" has stopped...Of course, where did this "moisture" come from?

And one more thing: That thing sure makes me smell terrible, even after driving it for 5 minutes. It is as if I stood directly behind the exhaust pipe for those 5 minutes. I do have the top and doors off, but it smells just horrible.!

and two more things: I went to a friends house and the lower radiator started leaking. Hahaha.

 

[AKR]

If, your engine does prove to have big issues other than just needing work on, or replacement of the head, upgrading is always an option, but will cost quite a bit. However, if you want to avoid extra expense, you could just drop in a rebuilt. For instance, I know several people that have installed an exchange engine from ATK. They are available from several of the 4x4 sites, including quadratec. Here is the link:

ATK Replacement 4.2L I-6 Engine for 75-80 Jeep® CJ-5, CJ-6, CJ-7, Cherokee & J Series Pickup - Quadratec

The cost of the engine (long block assembly) is about $2k (less the core charge), with the core only having to be the same kind of engine, no visible damage and having the ability to turn over when you give it to them. It comes with all the gaskets and you just have to swap over your accessories onto it, such as the starter, alternator, carb, etc.. The warranty on the engine is 3yr/unlimited miles.

Here's hoping all that I just said won't be needed though.

Looks like I could drop in a 5.9L V8....

 

[Les]

As far as the oil/water/black "spewage". the only time this happened was after I put in the new plugs. I think that one of the cylinders was not firing at all and then when I put the plugs in, it started firing.So there could have been a build up of moisture in there. Because now the oil/water "spewage" has stopped...Of course, where did this "moisture" come from?

And one more thing: That thing sure makes me smell terrible, even after driving it for 5 minutes. It is as if I stood directly behind the exhaust pipe for those 5 minutes. I do have the top and doors off, but it smells just horrible.!

and two more things: I went to a friends house and the lower radiator started leaking. Hahaha.

Ugh...your Jeep doesn't even belong to me, so why am I feeling like I need a drink?

Sorry to hear about all your difficulties....

 

[Al Lindner]

JEEP..... JUST EMPTY EVERY POCKET It will get better