Fouled spark plugs?

[rikubot]

Hi guys, beginner mechanic here. I've got a somewhat simple question. I recently pulled my spark plugs to see what kind of shape they were in since they were really rough since the last time I changed them. I found that half of them were very fouled, and the other half looked pretty good. The fouled ones had a tar-like substance on a good amount of the curved metal pin thing. Does this mean my rings are bad? I have been messing around with tuning my carb, but I thought it was doing alright. I want to say I probably have less than 500 miles on these new plugs. Anyway, thanks in advance for your input. Oh and I forgot to mention that I don't ever see grey smoke...

[c00nhunterjoe]

Pic of the plug.
When were the plugs pulled? I am assuming after it sat and idled? Very specific ways to read plugs.

[rikubot]

I pulled the plugs today after it was driven for a little bit. I'll upload the pic I took earlier when I get to my desktop.

[crj1968]

http://www.aa1car.com/library/spark_plug_fouling.htm

Likely it's from rings or valve stem seals...   

[rikubot]

I had a feeling it was rings. Is that a tough fix? I think I already know the answer...

[c00nhunterjoe]

Your response is what i figured it would be. To check your plugs for a "cruise reading" you should shut the car down and coast to the side of the road and pull them. If you went for a cruise, then drove home, accelerated up your driveway, idled and then shut the car down, your cruise readings are gone.

Also, which "half" of the plugs were fouled vs which ones were clean? All on 1 bank? Which cylinders?

[rikubot]

I'm pretty sure 6,2,5 and 1 were decently tar-like while the others looked more less okay.

[myk]

Please post pictures if you can.  Fellas, couldn't this be an ignition issue as well?

[rikubot]

Sorry that took so long. Here's a pic:

[crj1968]

Is the gap filled in with gunk? Hard to tell from pic.

[rikubot]

Yeah it had a good amount of it in there. Oddly enough that picture was taken with good lighting. And I lightened it a little. Sorry for the poor pic but yeah, it was gunked haha

[XH29N0G]

Do you have another picture across the gap?  I find it surprising that the porcelain is not completely covered, but am not an expert in this matter.

[rikubot]

I don't and I cleaned it up before I put it back in. I did find it strange as well that the gunk was only on the one side. It seemed concentrated on the side of the little curved pin.

[crj1968]

Well if it was me (and I'm no expert on the matter either) I think I'd go get a set of hotter plugs, maybe make the gap a little bigger, check timing and see how it goes.

It's obviously oil getting in...but you know, maybe you can get through the summer. 

You can also do a compression test and that could tell you if it's rings or valve seals.

[rikubot]

I see. I'll try to get my buddy to stop by and get his timing light on it. Any reason my rings or valve seals crapped out on me? I'll check my compression ASAP too so I can narrow it down. I'm looking for the gauge you put in the plugs and crank the motor? Should I stop driving it?

[rikubot]

Worst case scenario, my rings need replaced, can I do this with the motor in the car by pulling the heads and dropping the oil pan to get to the piston rods and pull the cylinders through the top?

[crj1968]

I don't see any reason to stop driving it. Worst it could do is foul a plug.

Yes a gauge you screw in to the plug hole and crank over- it has a check valve in it so it wont suck the gauge back down when on the intake stroke.

Probably would really be easier in the long run to pull the engine and go through it all if it needs rings.
 

What is the history of the motor? Sat a long time? Mileage? 

[rikubot]

She's got low mileage after the rebuild. It sat for a year or so, maybe a little longer. It got started every few months for about 5 or so years just sitting. I'd say less than 5k miles after the rebuild which took place around 2003-2004.

[PlainfieldCharger]

She's got low mileage after the rebuild. It sat for a year or so, maybe a little longer. It got started every few months for about 5 or so years just sitting. I'd say less than 5k miles after the rebuild which took place around 2003-2004.

If you were starting the car for short times and not driving it that will cause the plugs to foul..... Get some new plugs and go drive it about 20 miles and then pull the plugs and check them...

[rikubot]

Ok I'll pick up some new plugs next time I go out. I did want to say that my car does burn oil at a semi slow rate, but I have always had problems with leaky valve covers. I need to pull them tomorrow and get them fixed up. I don't skimp on gaskets either so I'm not sure what the heck I'm doing wrong.

[crj1968]

Oh man there's a whole thread somewhere about trying to seal up valve covers.

I FINALLY got mine to seal up with ultra copper sealer, on both sides of the gasket. lightly tighten, as not to squeeze out sealer.
Let set overnight, tighten further the next day.

It only took me 3 tries on the right side. 

[myk]

I couldn't solve my valve cover leak.  F**k it lol...

[rikubot]

I don't feel as bad about my leaky covers if you guys had issues as well. I always doubt my skills or lack there of.

[myk]

We've all been there/are there.  I'm not saying it's right, but it seems that sealing these things is more difficult than it should be...

[XH29N0G]

I keep thinking about writing this and then the description of tar-y substance makes me stop to think my experience is not relevant, but I will put it down anyway.  I had a black carbon fouling (and do have some oil on some plugs) with a recently rebuilt engine.  A lot of the carbon fouling went away once I properly tuned my car at idle.  I also had spent a considerable amount of time at idle trying to tune it for best vacuum.  My engine has a larger cam than I think you have, and wanted 20-22 degrees initial for highest.  I have an Air fuel gauge and I also saw that the best idle ended up considerably leaner.  I also found that the plugs have cleaned up.  I still have the oil, but it is on the back cylinders (not spread around like you describe) and I am suspecting the PCV. 

[MoParJW]

If oil is getting in your cylinders through the pcv system, an ''oil catch can'' will help in keeping your plugs (and valves) clean.

[rikubot]

I really appreciate the input. Funny thing is I've also spent a lot of time at idle tuning and fixing vacuum leaks, and I'm sure i had the mixture way to rich for a while too. This is the first carb I've ever tuned so I'm sure I have been doing a less than perfect job haha.

I'll slap myself just for the stupid question, but is the PCV valve the thing on the cover going to the carb?

[crj1968]

Yes. 

[XH29N0G]

.

[rikubot]

I borrowed a compression gauge from a friend today and could only check the passenger side before it got dark. I got around 75 on all four, and I only pulled one plug at a time and didn't have the carb all the way open, which I just read was wrong. Would doing this the correct way make that big of a difference from the high numbers I've been reading online?

[rikubot]

Thanks for the graphic! I'm not quite sure how it works though...

[myk]

.

Hmm....mine is set up so that the PCV goes into the carb, and the breather goes into the air cleaner.  Is that right?

[rikubot]

That's exactly how mine is set up as well.

[XH29N0G]

I borrowed a compression gauge from a friend today and could only check the passenger side before it got dark. I got around 75 on all four, and I only pulled one plug at a time and didn't have the carb all the way open, which I just read was wrong. Would doing this the correct way make that big of a difference from the high numbers I've been reading online?

75 seems very low to me.  It is not clear to me if the 75 was just the first bump, or was after 3 or 5 or after it stopped rising. I suggest redoing the check for all (the others will be a reference) with the carburetor wired open, paying attention to how much it rises with the first bump and then getting the final reading when it reaches a maximum.  If there is a difference then people here can guide you through other tests.

Other thoughts:  From what I understand, there is an effect of the carburetor being open, but my guess is probably not all the way to 75 psi.  I read 120-130 psi on an engine that I know had no more than 135-140 psi so I don't think it is too much of an effect.  I have also read high readings pulling only one plug, so I think that is OK unless it really slows the cranking speed.  Cranking speed apparently can have an effect.

One other important thing.  If you get a crazy reading, check the gauge to make sure it is reading correctly.  (Or buy a second one to check against.)  I checked mine using a bicycle pump and it would probably have taken less time to buy a second one.

[rikubot]

I probably should have cranked it longer. I am certain I didn't do a full 3 second crank of the motor. Ok, so when I get off work I'll do it again. I'll take all plugs out just in case that effects the cranking power, and wire the butterflies open on the carb. I might go get another compression gauge as well. How tight should I screw in the gauge? I didn't go to tight because I was afraid to chew up the O-ring on my buddy's gauge. Again thank you all for all the advice so far!

[PlainfieldCharger]

I probably should have cranked it longer. I am certain I didn't do a full 3 second crank of the motor. Ok, so when I get off work I'll do it again. I'll take all plugs out just in case that effects the cranking power, and wire the butterflies open on the carb. I might go get another compression gauge as well. How tight should I screw in the gauge? I didn't go to tight because I was afraid to chew up the O-ring on my buddy's gauge. Again thank you all for all the advice so far!

Get a battery charger on your battery too..

[crj1968]

.

Hmm....mine is set up so that the PCV goes into the carb, and the breather goes into the air cleaner.  Is that right?

Yeah it's right- the image just shows PVC going into intake...same thing

[XH29N0G]

I probably should have cranked it longer. I am certain I didn't do a full 3 second crank of the motor. Ok, so when I get off work I'll do it again. I'll take all plugs out just in case that effects the cranking power, and wire the butterflies open on the carb. I might go get another compression gauge as well. How tight should I screw in the gauge? I didn't go to tight because I was afraid to chew up the O-ring on my buddy's gauge. Again thank you all for all the advice so far!

Get a battery charger on your battery too..

Also watch the needle bump up until it stops rising.  You can to 4 or 5 bumps, but that is also close to where it stops rising.  Good luck.  The gauge needs to make a seal.  If you tighten it in by hand until it stops, I bet it will seal fine.   I don't think it needs to be tighter.  That is all I have done.  I would only get another gauge if you want one for yourself or you suspect a problem with the one you are using. 

[c00nhunterjoe]

Engine at operating temp, All plugs out, throttle wired wide open, fully charged battery. 1st needle bump should be minimum 90 psi on all cylinders. 5 bumps on each cylinder max. Report back numbers.

[Sublime/Sixpack]

Engine at operating temp, All plugs out, throttle wired wide open, fully charged battery. 1st needle bump should be minimum 90 psi on all cylinders. 5 bumps on each cylinder max. Report back numbers.

This 

[rikubot]

Ok thank you for the checklist. Any tips on not burning my hands off?

[c00nhunterjoe]

Most headers shouldnt be a big deal. I can have all 8 plugs on the fender in about 5 minutes with my $100 set of hedmans. Some use a ratchet with no extension, a few use a short extension, and 3 use the plug socket and a stubby wrench.

[rikubot]

I see. I'm more worried about threading in the gauge to be honest haha. It was kind of a pain in a cool motor. Should I just man-up and figure it out?

[crj1968]

I see. I'm more worried about threading in the gauge to be honest haha. It was kind of a pain in a cool motor. Should I just man-up and figure it out?

Gloves.    

[rikubot]

Haha I'll try my best. I'm damn near useless with my gloves 

[XH29N0G]

The headers will cool quicker than the engine.  Other's may say otherwise, but I think it is OK to wait for them to cool a little first.  I also doubt the 75 reading is just a warm/cold phenomena, but could be wrong.   I used those work gloves with Velcro from some place like home depot, they seem to give enough dexterity to manipulate and warning before burning.  Good luck

[Sublime/Sixpack]

At least have the engine fairly warm when doing the test.

[rikubot]

Got it checked up today after work. Thanks for all the help guys. My numbers were all around 95lbs give or take a few lbs per cylinder. I threw new spark plugs in it while I was at it. 

[XH29N0G]

Some quick clarifications:  

   What is your altitude? 
   How fast was the engine turning over?
   Is this for 5 or more bumps of the gauge, or just the first rise?  
   Was it 95 for all 8 cylinders?  If so was there any variation?

If it is 95 and there is no other reason for a low pressure (cranking or altitude - I think this could be equivalent to ~110-120 if you are in the mountains) , I would check the gauge and then see what others say.  

[rikubot]

Looks like my altitude is 4692 feet. I think the gauge bumped up at about 1 Mississippi. The driver side was closer to 97 consistently while the passenger side was closer to 93 consistently. How do I check the gauge for accuracy?

[crj1968]

found this:

150 at sea level = 125 PSI at 6000 ft.

I think you are probably OK for compression... 

[XH29N0G]

Looks like my altitude is 4692 feet. I think the gauge bumped up at about 1 Mississippi. The driver side was closer to 97 consistently while the passenger side was closer to 93 consistently. How do I check the gauge for accuracy?

I am still not 100% clear if you saw the gauge bump right up to 97 and the stay there through later bumps, bump to lower levels like 65, 80, 90, and ultimately level off at 97 after the engine turns over 5 or more times? 

Let me ask another question, does  the gauge have a valve that works so it stays at 97, or does it just bump up and the drop back down.

For what it is worth, the pressures you measure should convert to about 110-115 psi at sea level which is low, but consistent cylinder to cylinder.  This suggests to me that the oil you see and the compression are not related.  It is still low, so it might deserve some more checking. Someone on here will know if that is an issue.

I would just see if you can borrow another gauge and if you get the same reading.  I checked my gauge for accuracy using tubing and hose clamps to connect it to a bicycle pump that also had a gauge and checked to see if they matched.  If there is a source of compressed air and another gauge you could use that too, but the simplest might be to borrow or buy another gauge.
   
 


 

[rikubot]

Sorry about that, I replied this morning in a hurry and realized that I forgot to answer that part of the question. It was on the 4th or 5th jump of the gauge and it would hold until I hit the release valve. Any clue why my compression would be low-ish? She's pretty low miles.

[c00nhunterjoe]

What cam is in it? If its bone stock, then you probably have a 7:1 motor which sounds way off. Redo the test with a small spray of oil in the hole and see if the numbers jump up 15 or 20 psi.

[rikubot]

I'm actually not sure what cam is in it. I can't find all my paperwork from the rebuild, and I don't remember what they put in it. I want to say that it's bone stock besides the edelbrock. You mean way off as in way too low?

[firefighter3931]

What plugs are you running in this 440 ?  The dynamic (cranking) compression is low(er) than expected due to the mile high elevation. For every 1000ft of elevation you loose approx. 3.5% cylinder pressure. 

This is why cars that race at elevation are slower ; they're making less cylinder pressure and consequently...less power than at sea level. 

I'm not a fan of PCV valves....they will put oil vapor into the combustion chamber. I prefer to run a breather on each valvecover.

I would try a set of NGK XR4 plugs gapped at .035 and try running it with two breathers. Get the idle mixture as lean as the engine will tolerate and set the total timing to 40*.

You should have a nice blue/white spark....dull orange/yellow indicates resistance in the ignition system and a weak spark.

As for the low cranking compression ; it could be low static compression, a cam that's too big or a cam that was installed retarded.



Ron

[XH29N0G]

I just decided to try a check using one of the online calculators
I ran the settings in the image below through the dynamic compression calculator at Wallace racing:  http://www.wallaceracing.com/dynamic-cr.php
The cam specs are from http://victorylibrary.com/mopar/mpcam-tech-c.htm


It looks like it the stock cam (image) at 4500 ft with 9.0:1 compression would give 112 psi.  At a static compression ratio of 8.5:1 the calculator gives 103 psi for the stock cam. If your static compression is 9:1 or 8.5:1 then your numbers may not be that crazy.  A later closing intake like the 484 or 509 will drop the compression by by 5 to 10 PSI at these conditions.  Other variables could reduce the dynamic compression ratio.


So after thinking about it some more, you might be fine and the gauge may be fine too.  I would assume the gauge has a few psi uncertainty.

I am at sea level so am used to seeing higher dynamic compression numbers.  See if C00nhunter and Ron think this makes sense b/c they know more than me.  

[c00nhunterjoe]

Wow, i completely bombed that one... i thought i read "692" feet.... 
100 psi at nearly 5000 feet is about right for tye typical low cost, low comp pistons so since they are all within reason of each other, the bottom end is ok. Had the cylinders that had oil on them been considerably lower then the others, you would have had a probable answer for the oil, so now it is pointing more towards pcv or intake gasket sucking oil.

[rikubot]

Thank you all so much for helping me to pretty much eliminate the rings as the culprit. I'm really not worried about the oil much at all anymore. I have learned more about motors in this thread than anywhere else. Timing, compression, oiling processes, and more. Your extensive knowledge is highly impressive and I appreciate the time you all spent finding data and posting it. I learned a little more last night about heads and Pistons, so now I have a REAL question: should I get new Pistons, rods, and a cam???  

[c00nhunterjoe]

You shouldnt give up just yet. Definatly should pinpoint the plug problem. Oil Fouled plugs is never good. Are your valve covers baffled? Try as ron suggested and run with open bresthers for a few cruises and recheck the plugs to see if they stay clean.

[rikubot]

Yeah they are baffled. I think I have a spare breather to use as well. Should I disconnect the driver side to the filter?

[c00nhunterjoe]

Just for the test, yeah, run 1 breather in each cover, fresh plugs, drive, then recheck plugs. This will confirm or clear the pcv system as the culprit.

[rikubot]

I should mention that I was running M/T aluminum valve covers that had a very little baffles on them. I'm now running the original stamped steel covers. Think that would make a difference? And just today I finally got them to seal up! Lol

[rikubot]

I can post a pic of the bottom of that valve cover if needed.

[c00nhunterjoe]

I ran the mt fovers for years with pcv and never had oil problems. You might be sucking oil past the valley gasket.