Ok this post is for the Jeep/ Chrysler teach in the group. First I am not your average Tech. I have been a Factory trainer for GM, Navistar, FPT, And OEM Supplier Bosch. I currently tech a Heavy-duty Diesel and Equip. Program for GBC. I specialize in Fuel control diagnostics. But I Got one here that has me a little perplexed. My ’08 JKU this thing and a motor R&R about 40k ago under warranty from Mopar. Few weeks ago, I started this thing up in the am an was running like crap. Flashed the CEL with a P0300 (multi misfire). The day before this thing purred like a kitten and towed my boat home from the lake. Not following my own teaching I threw a few parts at it (cam, crank sensors and coil pack) with no luck. Rule number one- Cant fix a drivability issue on a bad motor. Always verify compression/ condition. Did a relative compression check saw some abnormalities, so Did a static. 1 and 2 cylinder was very low ( 80 one and 30 the other) so I thought burned exhaust vales ( 3.8 common issue) pulled the top end down to the heads. Pulled valve cover off right bank and #2 exhaust push tube was out from under the fulcrum ? kinda said WTF? Pulled the left cover same thing on #1 but intake.
Have any of you Tech seen this in the 3.8 or its little brother 3.3? if so what was the issue and the fix.
So I know lifters are and issue with the 3.8. never had any noise before. Could this be a lifter issue
I haven’t rotated the motor yet to determine cam issue/ lobe.
I have seen over rev’ed motors toss valve train components and or brake push tube/ push rods. The perplexing issue to me is parked ran flawlessly , next day cold start…dog crap.

 

I’d be curious to see your oil in the pan and see if you have a large amount of metal. My best guess is a cam lobe or the bottom of the push rod is destroyed. It is weird to run perfect upon shut down and have this suddenly in the morning though.

Sounds like you need to pull the heads anyways. Be sure to post pics and carnage when you see it.

In second thought, can you pull the push rod straight out and stick a camera in there to see the valves before you pull the head? It may be a simple spring issue on the opposite side of the rocker arm?

At least this will be an obvious thing when you take the motor apart far enough. I’d almost rather have that than a pesky electrical issue.

 

Nope and nope. Lobe still in good shape (verified with a dial indicator for lift at the push tube/ valve side) . I reassembled and did a leak down and there are no valve issue. Heads are off since this first posting and believe I found the issue this happen on both cyl intake both valve are a bit sticky in the guide. Heads and valve are off to the machine shop. Oh and the lifers are like new.

 

And btw you can pretty much see most of the the cam lobs from the lifter valley

 

Nothing loose so must be a collapsed hydraulic lifter. Weird that it is one valve on each side which could mean oil starvation in the same spot.

 

Maybe the valve springs are weak as well, along with valves sticking in the guide ???