keeps fouling #2 and #8 sparkplugs

[cblock]

Hi, i have a 71 c10 with a 350 v8, recently put in an hei distributor with new cap,rotor, spark plugs and wires. When I removed the old sparkplugs i noticed that #2 and #8 were prety bad , so i ran a compression test ,#3 had 60 psi, #7 had 90 psi and the rest have 120 psi, a few days later I blew out my 350 tranny, while removing it I saw that it was sucking transmision fluid through the modulator. It now has a 700r4 transmision from a 92 astro. But about every 100 miles it keeps fouling #2 & #8 sparkplugs, i take them out, clean them and it'll run fine till it fouls them up again, I dont know if its unburned gas or oil, any comments are greatly appreciated. Thanks

[Grumpy old man]

Sounds like it's time for a rebuild or engine replacement .

[hugger6933]

Check the spark plug wires you may have a couple of them breaking down under a load. If nothing else move the 2 and 8 wires to another place they will fit and see if the plug fouling moves with the wires. That is the cheapest way to start looking for the problem. Jim

[hamjet]

Originally Posted by hugger6933

Check the spark plug wires you may have a couple of them breaking down under a load. If nothing else move the 2 and 8 wires to another place they will fit and see if the plug fouling moves with the wires. That is the cheapest way to start looking for the problem. Jim

Plus switch the two plugs to different cylinders and keep track of where you put them. cleaning does'nt always fix plugs that are on their way out..

[Grumpy old man]

Left bank has low compression on 2 non adjacent cylinders

Right bank has oil fouling on 2 non adjacent cylinders

recently blown turbo 350 sucking tranny fluid thru engine

I'd like to see a picture of the inside of the valve covers and the engine in general

[Lanman1972]

I had a corvette that would foul/oil soak the same plugs. It always had the puff of smoke on start up and after I had the heads redone all this went away. Valve guide seals were shot and valves needed work. I think HEI needs the plugs gapped wider.

[5567Cruiser]

Sounds like bad valves to me or the need for some head work.A temporary fix would be to go to a hotter range spark plug for example R44T to R45T A/C plug.Just an idea, good luck.

[cblock]

Thanks to everyone for there feedback, the sparkplugs are new ac delco r45 gapped at .45,
the cables are also new and when it had the old points system it messed the same 2 sparkplugs, the truck sat for 10 years so i'm slowly geting into daily driver conditon. Has anybody used sparkplug extenders?

[trac209]

If this truck sat for ten years it is possible some of the rings are sticking. What you can do is pull all the plugs and put some trans fluid or marvel oil into the cylinders. Let that soak overnight and then turn engine over with the plugs out to get rid of the oil. This has worked for me in the past to unstick a ring or two stuck from sitting.

[Grumpy old man]

marvel mystery oil can work wonders on stuck rings and valves . We have used it (unapproved by the FAA) to raise low compression readings on air cooled piston type aircraft engines that can build up lead deposits on valve seats . we would pull the top spark plug (2 per cyl upper and lower ) and pour in marvel and let it sit overnite ,next day DRAIN the cylinders and using a large dead blow hammer we would smack the top of the valve stem and when the valve slapped back it would bust loose the lead deposits and allow the valves to seat better thus raising compression readings and avoiding pulling the jugs (cylinders) for a valve job , Just don't tell the FAA inspectors they know it works but Marvel refused to divulge the ingredients and FAA refused approval . try it (the Marvel oil not hitting the valve )it's less than $10.00 and may help your problem worst case is your out $10.00 and your engine compartment is coated in Marvel. MAKE SURE YOU REMOVE ALL SPARK PLUGS AND CLEAR THE CYLINDERS BEFORE YOU TRY TO START IT TO AVOID THE LOW CHANCE OF HYDROLOCK . check with your local parts store for acceptable hotter plugs .

[leftybass209]

Let's say this is a stuck ring issue. You've already ran the engine a significant amount of time with stuck rings, so you've had the pistons bouncing and vibrating off the cylinder walls a good amount of time. I guess in your case it doesn't hurt to try something else, but be prepared for an engine rebuild or replacement soon.

[Grumpy old man]

Originally Posted by leftybass209

Let's say this is a stuck ring issue. You've already ran the engine a significant amount of time with stuck rings, so you've had the pistons bouncing and vibrating off the cylinder walls a good amount of time. I guess in your case it doesn't hurt to try something else, but be prepared for an engine rebuild or replacement soon.

That's what I said, But may as well chase the cheap easy cures before pulling the engine lift out of the garage . A picture would answer a thousand questions and provide some solid opinions .

[trac209]

Originally Posted by leftybass209

Let's say this is a stuck ring issue. You've already ran the engine a significant amount of time with stuck rings, so you've had the pistons bouncing and vibrating off the cylinder walls a good amount of time. I guess in your case it doesn't hurt to try something else, but be prepared for an engine rebuild or replacement soon.

I'm gonna say that's very very doubtful,and a rings job is not to prevent that in the first place.

[leftybass209]

Originally Posted by trac209

I'm gonna say that's very very doubtful,and a rings job is not to prevent that in the first place.

Doubtful, maybe, but I've seen direct evidence of this happening in quite a few engines . I know what the job of the Rings are, btw.

[GASoline71]

If it's the original 40+ year old engine... it's probably just plain worn out. Like G.O.M. said in the first response, it's time for a rebuild or replacement.

Everything else is just a band-aid prolonging the inevitable.

Gary

[Al1957]

Put AC 46 plugs in the cylinders that are oil soaked, they will last longer, sure it's a temp fix, but will keep you on the road.