3.8 valve train issue

[MikeSW214]

First off hello. Been a jeep fan and builder and overlander since I was in HS many moons ago. I owned '76 cj5 golden eagle ( wished I still had that one) an 70' Kaiser v6 CJ5,l. '86 cj7,That was a major build with a fiberglass body to port 350 head p435 trains Dana 300 transfer case. 1997 TJ 44 axle swaps geared on 35s. Then I decided I wanted a four-door. So I bought 2008 Sahara with an automatic. And we put quite a bit of miles on this thing For the most part it's been a good Jeep.

So is there Jeep/ Chrysler tech 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 teach 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.

 

[BLACKJKU]

I'll have to say i've never seen anything like that on these engines but usually when something like that happens it's because a timing belt or chain broke. But if you say it was still running then it didn't break. Does the rocker arm still move freely? Maybe try pushing the valve down to see if it's stuck.

Do you have one of those cameras you could pull the sparkplugs and look inside the cylinders?

 

[MikeSW214]

Yes ran a borescope down the cylinders. Can't quite get it to turn up the see of valves. I haven't pulled the heads but I'm that close I'm going to. Like I said ran perfect shut it off next day ran like crap. And was still running when I pulled it apart. The more I can do now valves are not stuck open springs are not broken The one push tube that got wedged over was bent up on the head end not the lifter end. The other one looks perfectly straight.

 

[BLACKJKU]

See any possible valve marks on top of the pistons? Also I read where there could have been a problem with the roller lifters failing and maybe causing that.

 

[BLACKJKU]

Did you have any luck finding the problem?

 

[Rootsfly]

Any reason for this found. I had this happen to #1 intake three years ago. Put it back where it should be. Now just had it happen again. It was a cold start in the morning. It was running perfect before. Valve seams fine.
Mine is a 2007 JKU with 72k miles. Thx for any input.