I think I found my problem????????

[art leong]

I took off my valve cover today, to look for a busted spring, wiped cam etc.. And found everything in order.
On my motor Chrysler machine a 5/16 hole in each camshaft. To get cams alligned. Both holes are supposed to be in line with the other. Like a goal post. This makes it easy to align the cams. Well tonight I noticed that my intake cam was straight up and my exhaust was tilted slightly back (almost a tooth off). The cam bolt is tight (used loctite red on it).
But somehow the cam seems to have moved.
I've decided to pull the motor and check the bearings, and do a bit to the head.
I kept checking the timing as I was fighting this problem. And because it didn't move I figured the cam timing didn't move either. But my sensor is on the intake cam not the exhaust. So there was nothing to indicate the problem.
Now I have to figure out if it was this way for a long time or it happened when I started using the 2 step?

Heres a pic of the way the holes line up.

[BillK]

Art,
Which engine is this ? I see a pin in the front of the one cam but not in the other ?

[Adger Smith]

You said I would hear a big Yahooo all the way from Georgia when you found it. You must be out of breath from working on it so hard!!!
I ask you that 3 weeks ago... I'm going to have to whoop you!! I'm sure going to miss our long conversations about your little screamer. It did help me understand your system. Now we can see if all that injector location and port shape/size works... HA!! YES!! Joe, I'm going to miss your input, too. Very informative. Thanks. OH, Art. The card game I left you for tonight was a draw.... :~) I had to play with the big cards so I could see what was in my hand. Did pretty good for a guy blind in one eye that can't see out of the other. ;~)

[Tom keedle]

don't suppose you have a lot of spring pressure and that it's making the cam move in the cam gear?
if so, can you pin it in place?
my experiance with DOHC neons is on daily driver stuff...

[art leong]

Originally Posted by BillK

Art,
Which engine is this ? I see a pin in the front of the one cam but not in the other ?

The pin on the intake cam is on the up side, the exhaust cam is on the down side.
I'm going to get some square stock turned on a lathe to fit in the holes on the top of the cams. And make a jig up to hold them.

[Adger Smith]

Art, I have an idea for a design. Call me

[buzzinhalfdozen]

Art, I'm so glad you found this, been gone to the Sportsnats with my kid so been out of touch. As agrivating as this was for you it did at least allow you to look deeper into the operation of your system. Knowledge is power and the more we understand the easier problem solving becomes. Nice job. Joe

[art leong]

Originally Posted by buzzinhalfdozen

Art, I'm so glad you found this, been gone to the Sportsnats with my kid so been out of touch. As agrivating as this was for you it did at least allow you to look deeper into the operation of your system. Knowledge is power and the more we understand the easier problem solving becomes. Nice job. Joe

Thanks Joe. But no cigar for me this time. I put it back together and while it "seemed" to run better. I still have the same problem it didn't go away. I almost can't believe that moving an exhaust cam a tooth (decreasing lobe seperation by 9 degrees). Would not show any difference. The cams look allright (not wiped) I'm wondering if my lifters (hydraulic) could be damaged. But they don't make any noises you would connect to a collapsed lifter. I did change from Schieffer 20w50 to Mobil 1 0w30 (both synthetic) Back when I started having troubles. I'm running out of things to look at.
Is it possible that the lifters are collapsing, and not making noises.
I'm thinking change the lifters, then maybe change the cams (I have some smaller cams)
And check the cams on the bench. The exhaust cam thats in the motor now is a welded regrind, but it doesn't look bad.

This whole experience is making me think of the commercial for the Holiday Inn Express. "No But I Stayed At A Holiday Inn Express Last Night"

[buzzinhalfdozen]

Art, that's not good news. One way I have found intermitent valve issues ie. valve sticking in guide weak spring ect. is by doing a running compression test. This requires removing the schrader from you tester so it doesn't hold pressure, running the engine you will see the needle fluctuate wildly however if you look at it closely you will see where it hits its high number. watching for the needle to not go to that high number at times is an indicater that something in the valve system is amiss. I would think this test would pick up a lifter thats bleeding down as well. As far as it making a noise I'm unsure of the answer to that as the cam is always in contact with the lifter and it bleeding off and not moving the follower, I would think would result in no detectable noise, it simply would not move the valve.On stock engine these problems are easier to find with a simply vacuum gauge as they produce a quite smooth vacuum signal and a fluctuating gauge would indicate further inspection.On the plus side you do have an 02 sensor, that should indicate a mis firing cyl. as a lean condition.

[art leong]

Upon further inspection I see the rockers have been wearing where they make contact with the valve.
Going to pull the head now to get a better look at the valves.