New wrinkle - air coming from intake when turning over

[SketchyPete]

Hi all,

As you may be aware my car has a no spark condition. Well, while turning it over to diagnose, we found air blowing out of the intake.

To us, this meant a burnt/broken valve, broken spring, wiped cam lobe or bent pushrod.

I removed the valve covers and found this (pic 1).

The rocker was finger loose. I removed it by hand to inspect the pushrod. (Pic 1,2,3)

Next I inspected the rocker and cylinder head

 

[SketchyPete]

I'm looking for opinions as to the next steps. The threads in the rocker look fine, but you can see where the rocker has been worn and I'm think it would be best to replace.

I'm not sure what to do about the mounting surface. It seems a little rough to me, should I clean that up a little with Emory cloth or is there supposed to be some texture there?

 

[SketchyPete]

I notice some sparse and microscopic amounts of sparkle in the oil. Is it post that this wear on the rocker is responsible? The amount of metal is small enough that the oil looks clean unless you look very hard with a flashlight at an angle. I would describe the amount of specs as like looking as a fairly open area of night sky, so I would say about as minimal as I have ever seen, but still there.

So does anyone know the torque spec of the rocker?

I'm wondering if I need to pull the pan and inspect some rod bearings and pull the cam to check for damages.

Or change the oil, cut upon old filter, replace rocker and roll out?

 

[SketchyPete]

The pushrod looks perfect so I'm leaning towards the cam being ok

 

[SketchyPete]

I pulled the adjacent rocker and to me it looks the same, even having a "wallered" look on the bottom. I think the thing just wasn't torqued. Which opens an whole host of other questions...., Not sure how it could have worked it self loose.

 

[MoparMap]

Rocker arm torque is 26 ft-lbs per the service manual I have at least. I probably wouldn't be super worried about the slightly rough looking surface there since it's really not a moving part, so don't know that it would need a nice mirror finish.

As for other things to look for, I think it might be worth pulling the pan and checking the rod bearings. The engine doesn't have cam bearings, the cam just rides straight on the block journals. That could potentially be causing the sparkle in the oil. The bad news there is it's not really something that is very easy to fix. It has been done before, but I think the more common "fix" is a brand new block. I found an old magazine article I saved where someone actually found a shop that took on the challenge and bored out the original cam journals so they could install bearings. I think it was a gen 2 block though, but not sure if that would matter or not. The closed valley design and extra long nature of the V10 just makes it very difficult to machine and install bearings.

 

[SketchyPete]

Hey Moparmap, would you please share that article of the shop that did that? It really shouldn't be that hard to machine for cam bearings. At the least couldn't the journal be bored and use a custom grind to fit the new size?

 

[MoparMap]

Maybe, on the overbore, but I'm not sure how much meat is there and what the oiling and stuff looks like. I think the big issue was more that a traditional boring bar is usually supported along its midsection by extra support pieces on the machining equipment. These would normally reach through the valley or from the bottom side of the block to help support the bar when it's cutting the deeper journals to keep it from chattering. I think the solution they found was a boring bar for an old straight 8 engine or something like that that was just super rigid to start with. Looks like it's a bit too big to attach here though. Mind PM'ing me your email and I can send it to you?

 

[SketchyPete]

I don't seem to be able to figure out how to pm LOL. I clicked your tag and it opened conversations?

 

[BlackWidow]

@SketchyPete after you click on the avatar, click “start conversation”