Vortec Heads Suck...

[SquareRoot]

oil past the valve seals?

Here's the deal:

Noticed a misfire at idle. Started pulling plugs to look for clues. #1=good. #3= oil fouled! Bingo. But the question is why?
This is a new gm crate motor with about 2k miles on it. I swapped new GM Vortec heads on it 1000 miles ago.

So I cleaned the plug with acetone and a wire brush. Swapped plug #1 with plug #3. Drove it for two days. Today I pulled the plugs and #3 is getting oil fouled again (originally plug #1).

Concluded it's not the plug. Inspected and ohmed the plug wires (new Moroso 8 mm low ohm). Wires are good. Swapped in a brand new spare cap, rotor and coil.

Gonna drive it a few days and pull the plugs again. If #3 us going south again I can conclude it's not the ignition.

Therefore, I'm assuming it can only be the valve guide seals or piston rings?

What say you all? I never even looked closely at the valve guide "umbrella" seals. I'm just assuming they have them?
Am I missing something here? I'm having a hard time believing that a new engine would have this condition.

I was hoping I just had a plug go bad but the problem didn't follow the 1-3 cylinder swap.

 

[Frankenchevy]

Odd, I haven’t had any oil burning or fouled plugs and afaik the Vortec era trucks were great—aside from spider injectors and 4l60 1-2 slip.

Mine however is an unmodified L31-r from GM.

 

[shiftpro]

I would say it's the shoddy quality control these days. Were the heads (valve and seats, guide clearances) inspected before they were installed?

 

[SquareRoot]

I would say it's the shoddy quality control these days. Were the heads (valve and seats, guide clearances) inspected before they were installed?

Nope. Bought from Summit. They came in OEM gm packaging. Other than a visual inspection, I saw no reason to dig too deep into inspecting new parts.

Engine has been running great until now. After I swapped plugs I only drove it to work 2 days ( 50 miles at most ). In that short time the clean plug was already showing signs of oil fouling.

That's why I'm thinking a seal went bad?

 

[mtnmankev]

WARRANTY TIME !!!!!

 

[shiftpro]

Nope. Bought from Summit. They came in OEM gm packaging. Other than a visual inspection, I saw no reason to dig too deep into inspecting new parts.

Engine has been running great until now. After I swapped plugs I only drove it to work 2 days ( 50 miles at most ). In that short time the clean plug was already showing signs of oil fouling.

That's why I'm thinking a seal went bad?

Since it ran good the valves are no doubt sealing. But this is not always the case. At the very least it's a good idea to shoot some WD40 into the ports and see if it leaks out past the valves. But you're good here and I just wanted to make this point for all to see.

I would venture the same as you, a seal has taken a crap, or somehow worked it's way partly off the stem.
So you need a valve spring-in-head removal tool or you can make one if you have the junk. Old school way to hold the valve up is by threading a few feet of cotton rope into the cylinder through the plug hole. Gently hand crank the engine until the valve is up tight against the rope.
Or,
pull the head. Eeesh...

 

[SquareRoot]

Agree. Anyone know if the OEM seals on vortecs are umbrella type or the posi lock?

 

[DoubleDingo]

I'd agree on a seal gone bad. As to the type of seal I don't know for sure. I've had good luck with my vortecs thus far

 

[SquareRoot]

Did a compression test tonight. Took readings on 3 cylinders for comparison.

All 3 read right at 120 psi.

On cylinder #3 (where the fouled plug is), I did 3 tests dry, added an oz of oil and repeated. Wet or dry, the psi was 125.

I think that rules out any issues with the rings.

Tomorrow I will pull the valve cover and see what I can see about those umbrella seals.

 

[PrairieDrifter]

They should be umbrella style seals.

 

[SquareRoot]

Update:

I'm a *******.

Not sure why I was using the Accell plugs other than they were the shorty version for header's.

Didn't realize the threaded side was about a 1/4 short. To add insult to injury, the porcelain side is less than an 1/8th inch shorter. The standard AC Delco's fit fine with header's. Now that the tip is actually in the combustion chamber I'm hoping that fixes the fouling issue.

Pulled all the plugs and did a compression check. All 8 cylinders are exactly 130 lbs.

I'm swapped over the Edelbrock Pro-flo 4 this week.

I'm thinking life is good again.

For future reference, those autolight plugs are a mile long.

You must be registered for see images attach

You must be registered for see images attach

 

[Hugeroost]

Squareroot, that's a damm good thing to know, who woulda thought there was that much difference in plug size. I guess your gonna have to change your thread title, those heads are really good that's why I clicked on it to see what was up....Roost

 

[DoubleDingo]

@Hugeroost That's why I clicked on the thread too, I was thinking, "vortec heads are pretty dang good". I do know that I specified 1996 vortec spark plugs when I installed mine, and they are long.

 

[SquareRoot]

So far, the Vortec heads have been great. Hopefully, using the correct plugs will solve the fouling issue.

 

[SquareRoot]

The mystery has been solved! A bit of a head scratcher, but it makes sense now.

I pulled the intake off last night in preparation for the efi swap. This is what I found.

My first thought was how the hell could I have put two gaskets on? Impossible. I only had one set and I'm not that stupid normally. After staring at it for awhile, it started to make sense.

The gaskets delaminated and shifted causing the intake ports to leak. The cylinders with the fouled plugs coincided with the intake runners having an oily film in them.

Pulled the valve covers and the valve stem seals are just fine.

This was likely caused by my failure to follow directions included with the Edelbrock intake gaskets. It says to apply Gaskacinch gasket sealer on the head side and a thin coat of rtv around the water jacket ports on the manifold side.

I did NOT use gasket sealer. However, I did not expect this to happen.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach