What the heck would cause this?

[Big_P]

Side-work-customer of mine had a 98 Caravan 3.3 with what sounded like a lifter tick. The car had 160k miles and it didn't sound threatening so he just kept driving.

Then it died on the highway. He got it towed to his house a few weeks ago and I finally got around to looking at it. I pulled the valve cover and found this:


One of the valve stems holed the rocker arm . The valve keepers were totally done-zo and the spring popped off the valve, letting it float and beat on the piston. The valve moved up and down fine, though, with no excess resistance. The top of the valve was "mushroomed" compared to the top of the other valves.

I don't see how this could happen except for a sticky valve? that somehow un-stuck itself? Seriously, it moved up and down by hand very, very easily.


The following picture shows that cylinder 2 was also ready to shoot through the pushrod. Wayyy too much wear.


The engine was absolutely full to the gills with sludge. It was weird because I know he gets his oil changed on time (maybe a hair overdue once in a while, but he has a long commute and drives all highway)

So what we did was remove the pushrods for that cylinder (6) and he's going to limp it to the dealer to get his $ for cash for clunkers.


Weird, though. Thoughts? Thanks

[Big_P]

Nobody?

[Mario]

Was he the original owner?

[karlak]

Quaker State motor oil and its protective film....
http://grassrootsmotorsports.com/for...k/12649/page1/

[Big_P]

Was he the original owner?

No, but he has had it for ten years.

[mpgmike]

This might sound like a stretch but my guess is a faulty PCV system. If the oil is changed regularly and looks like that inside, the sludge is coming from the blow-by accumulation in the oil. Not that it matters now, but PCV system failures have shown these results on many various engines.

Mike

[airagitated]

Mpgmike types the truth.

[JDAWG]

I have seen the newer 3.3/3.8 break the camshaft in half, dunno why

[mopar-tech]

Looks like extended runs between oil changes, looks pretty ugly.

Last time I saw a motor like that it was a 3.9 that had 34k on it and 3 oil changes in its whole life.

[Ondonti]

3.3 ftw

[Vigo]

That's definitely not normal breakage for a 3.3. I mean, ive only got 230k of driving experience on 3 different ones to go off of, not to mention never ever having taken one apart in my years as a tech at various places..

I dont see how the keepers could have come off, at any rate. Seems like the hole-punching would be a lot more likely if the keepers came off first and the valve was hitting the rocker full speed while the piston was pushing it up, and the lifter probably pumped up all the way.. dunno, its a stretch.

Weird find.

[JohnnyIroc]

Looks like extended runs between oil changes, looks pretty ugly.

Last time I saw a motor like that it was a 3.9 that had 34k on it and 3 oil changes in its whole life.

whats wrong with that i change my oil every 10k too

[GLHNSLHT2]

I doubt it's PCV related I don't have PCV on my car and my oil doesn't look like that. Looks like cheap sh1t oil to me. Tell him to try a little mobil 1. Jeeze.