2002 4tec broken valve & following carnage

[68ragtop]

I was somewhat under the assumption that the early 4tec solid core valves didn't have many issues with breaking, but I just tore one down that did exactly that. On this one the exhaust stems looked pretty rust free, but it was the intakes that had some rust. At first it looked clear that the stem snapped in a similar way the 2004-2006 style are know to do. What I thought was interesting is it appears there has been some contact with the failed valve & the relief cut in the piston dome. So now the question is, what happened first.

No other marks in the remnants of the broken piston , or in the other two pistons.

Seems a little odd.

 

[68ragtop]

based on the adjustment slots the cam was retarded as far as it could be. Exhaust valves look unremarkable, but the intakes have rust. Nothing that looks pitted, but for sure rusty.

 

[mkov608]

That sucks! I have two '02 ... both just over 100 hrs. Wonder If I need to pull the heads and replace the valves. How many hours are on your '02?

 

[68ragtop]

That sucks! I have two '02 ... both just over 100 hrs. Wonder If I need to pull the heads and replace the valves. How many hours are on your '02?

I think this is the exception & not the rule. I would't worry about yours just yet. I think something odd was going on in this engine & I haven;t put my finger on it yet. I bought it this way, so hard to say what if any symptoms it was having. just over 100 hours & spotless everywhere else inside the engine.

Interestingly, the rocker for the exhaust valve was broken & I thought it was from the valve head getting compressed, but there is not evidence of that. I'll pull that valve to see if its bent at all. There's a bunch of marks that it would seem it ran for quite a while with the brocken rocker arm.

just weird how it was hitting the piston. But I know weird dynamics can happen when things start to come apart . especially at higher RPMS.

 

[mkov608]

I've seen rocker arms crack in other engines, but I've never seen one break. I did see a broken camshaft once when the piston hit the valve, and the force was transmitted through the rocker arm to the cam. I can see how impact with the piston would break the valve, but now the question ... why was the piston hitting the valve?

 

[68ragtop]

And... only the valve that broke was hitting. Measuring things a bit more, The stem from the broken valve is bent above the guide on the spring pocket side. It's possible the rocker for the exhaust broke first & the "parts" got into the intake valve train & bent the shaft. then maybe it was getting stuck & then hammered by the piston until it broke?

But, if thats the case what broke the rocker arm on the exhaust valve? Its evident it ran for a while with a broken rocker, but not very lock with the dropped valve head.....

Hopefully others can share what they know & see too.

 

[racerxxx]

Hey Carl, I think you found your problem.