Riddle me this........new motor blues

[Rox Crusher]

Love the performance of the new 351 but have been chasing a couple issues and looking for advice

At about 150 miles the check engine light came on, ran it that way for another 50 or so until I got a code reader. #8 mis-fire was the only code. I can erase the code but it returns whenever the engine is to temp and has any load beyond idle. Can't really feel a run issue but the code keeps popping up.

I also have a small leak at valve cover, right at back of head above #8. When I removed the upper intake to get at the valve cover I noticed more oil than normal in the #8 runner of the upper intake. A little in #7. Cleaned it up and tightened up the valve cover and stuck my head back in the sand.

Swapped a couple plug wires around to determine if the #8 wire was the cause of the code. Code remained at #8 so wasn't the plug wire. Pulled the plug, it looked a little oily / fuzzy on one side and clean burn on the other side of plug. Cleaned it up and swapped plugs between 7 & 8. Code keeps coming up.

Have run it this way for a another couple hundred miles continuing to monitor codes, etc. # 8 misfire was only code until today. I also got "no DTC definition detected", whatever that means.

Meanwhile, valve cover still leaking so I decided to swap to another type of gasket. When I removed the upper this time there was even more oil in the upper intake. #8, 4, and 7 all had oil but everything else bone dry. #8 had about 2 teaspoons and 4 & 7 probably about 1 teaspoon in each. #8 plug kind of dark / oily for a plug with less than 500 total miles on it (200 since having cleaned it). See the pics.

So, where the hell is all of this oil coming from ?

[Viperwolf1]

You know this is going around full circle to a compression test. Good thing you didn't use P heads. Oh wait, you did.

[ZOSO]

Comp and leak down tests will tell you alot.

[RJLougee]

How is the PCV setup run? My thoughts are leaning toward some excess oil coming in from a weak PCV valve. Underlying cause of that........
HTH, Joe

[ZOSO]

How is the PCV setup run? My thoughts are leaning toward some excess oil coming in from a weak PCV valve. Underlying cause of that........
HTH, Joe

And if this is the case a Good quality catch can will help a lot. But it is a sign of some serious blow-by.

[Rox Crusher]

How is the PCV setup run? My thoughts are leaning toward some excess oil coming in from a weak PCV valve. Underlying cause of that........
HTH, Joe

I'm running early mustang EFI valve covers which are sealed other than a vent line in the oil filler tube which runs over to the throttle body.

The PCV valve is plumbed between the port at at the back of the lower intake and a 3/8 tube into the upper intake.

[RJLougee]

I'm running early mustang EFI valve covers which are sealed other than a vent line in the oil filler tube which runs over to the throttle body.

This line basically provides metered/filtered air to the PCV system.

The PCV valve is plumbed between the port at at the back of the lower intake and a 3/8 tube into the upper intake.

Which 351W/5.8 lower are you using? Is the PCV matched to that intake/setup?
Joe

[Rox Crusher]

I'm running early mustang EFI valve covers which are sealed other than a vent line in the oil filler tube which runs over to the throttle body.

This line basically provides metered/filtered air to the PCV system.

The PCV valve is plumbed between the port at at the back of the lower intake and a 3/8 tube into the upper intake.

Which 351W/5.8 lower are you using? Is the PCV matched to that intake/setup?
Joe

I'm running the Ford Racing version of the lightening lower. It has the PCV valve located at the very back of the intake. It uses the little wire filter basket with the PCV valve sitting on top of it in the rubber gasket / sleeve.

We believe we found possible solution.........my Explorer upper (from a 98) has the PCV valve plumbed directly into a 3/8" vacuum line whereas the 96 Explorer upper on Phil's has the PCV routed to two ports, one of them at the very back / lower corner of the upper. We theorize that this routing allows the accumulated oil to drain back down through the PCV when the engine is turned off. Mine doesn't have a way to drain back.

We're going to do the compression test tomorrow and re-rout the PVC plumbing.

[ZOSO]

What did you find?

[Rox Crusher]

We reconfigured the PCV routing as mentioned previously to allow the excess oil to drain back.

We also added a big baffle to the underside of the upper intake. This should help reduce the amount of oil being pulled up through the PCV to begin with.

Also, yesterday Garry did some additional tuning to counter an IAC code I kept getting.

We could see a slight miss and the left bank was running lean.

Whatever adjustments he made were perfect because it runs like a champ now !

[ZOSO]

What iac code? I kept throwing p1506 iac speed codes. Every down hill it tossed a code.

[Viperwolf1]

What iac code? I kept throwing p1506 iac speed codes. Every down hill it tossed a code.

That's the one Jeff and I used to get. Gary has a fix for it now.

[ZOSO]

What iac code? I kept throwing p1506 iac speed codes. Every down hill it tossed a code.

That's the one Jeff and I used to get. Gary has a fix for it now.

Good to know. He'll be getting a call from me soon.

[TOOLMAN]

We reconfigured the PCV routing as mentioned previously to allow the excess oil to drain back.

We also added a big baffle to the underside of the upper intake. This should help reduce the amount of oil being pulled up through the PCV to begin with.

Also, yesterday Garry did some additional tuning to counter an IAC code I kept getting.

We could see a slight miss and the left bank was running lean.

Whatever adjustments he made were perfect because it runs like a champ now !

I know this is an older post, but I'm having a problem with oil draining out of the lower rear vacuum port (right above the valve cover). I think I need to do this modification. Do I just put a tee in that rear PCV line? I'm not really seeing in my head what's involved.

[Rox Crusher]

We reconfigured the PCV routing as mentioned previously to allow the excess oil to drain back.

We also added a big baffle to the underside of the upper intake. This should help reduce the amount of oil being pulled up through the PCV to begin with.

Also, yesterday Garry did some additional tuning to counter an IAC code I kept getting.

We could see a slight miss and the left bank was running lean.

Whatever adjustments he made were perfect because it runs like a champ now !

I know this is an older post, but I'm having a problem with oil draining out of the lower rear vacuum port (right above the valve cover). I think I need to do this modification. Do I just put a tee in that rear PCV line? I'm not really seeing in my head what's involved.

Yup, just plumb in a tee in the line at that port. I can’t recall if mine had a port that was capped or a boss that we had to drill out.

[TOOLMAN]

I'll try it...Cheap fix (if that does it!). Thanks!