Gen 2.5: Broken camshaft pin and other interference engine wins

[BEG]

My timing belt tensioner failed while I was driving a few weeks ago. I had it towed home, opened everything up and was surprised to find that the belt had not skipped and everything seemed to be in time. I bought a new tensioner, went through the whole tensioning process a few times until I was satisfied and then started putting her back together when I noticed that the driver's side cam gear looked funny. The locating pin was sticking out proud of the cam gear (the passenger side pin is flush) and was bent. The cam gear bolt flange was also damaged. When I removed the cam gear, this is what I found:



The cam gear pin was sheared off at the snout and the cam itself was off about 90* before TDC. I imagine some significant valve-to-piston contact had to happen for it to snap like that. I'm imagining the worst (bent valves, damaged piston, maybe even a hole in the cylinder wall) but I figured I'd start with a compression test and go from there, and for that I need to get the timing belt back on. I can get a new cam gear and bolt. No source for the pin yet, but maybe I can get some dimensions off the passenger side and order a generic one unless anyone here has a part number. Also, any ideas on removing the broken pin from the snout?

 

[nckwltn]

yikes... what a nightmare... I'm not exaclty sure how the pins are held in, so I'm not sure how they would come out... my initial thought would be to drill it out, but thats kind of a brute force method.

If you're just wanting something to be able to check compression, you might be able to weld something to that pin (but there isn't much left sticking out of the cam to weld to)...

I agree with checking compression a an initial step, but to get there, you're taking off all of the intake to get access to the plugs. At that point, you're only a few bolts from pulling the head off for some visual inspections.

how many miles on the timing belt & tensioner? now with it failed, does the tensioner pin just flop in and out of the tensioner housing?

 

[BEG]

yikes... what a nightmare... I'm not exaclty sure how the pins are held in, so I'm not sure how they would come out... my initial thought would be to drill it out, but thats kind of a brute force method.

If you're just wanting something to be able to check compression, you might be able to weld something to that pin (but there isn't much left sticking out of the cam to weld to)...

I agree with checking compression a an initial step, but to get there, you're taking off all of the intake to get access to the plugs. At that point, you're only a few bolts from pulling the head off for some visual inspections.

how many miles on the timing belt & tensioner? now with it failed, does the tensioner pin just flop in and out of the tensioner housing?

I'm pretty sure it's just an interference fit. I did think about welding something to the pin. I'm pretty good at getting electrodes stuck to my work piece, lol. But I can't get my welder all the way out there without cobbling together an extension to my dryer socket.

Drilling would be tough since those are typically hardened pins.

You're right about the compression test though. I forgot about having to remove the intake for plug access. I guess I'm still hopeful that everything's ok in there.

The timing belt is brand new as is the water pump, and all the associated gaskets and pulleys. The ONLY part I didn't replace was the tensioner because it tested ok according to the manual.

 

[nckwltn]

The timing belt is brand new as is the water pump, and all the associated gaskets and pulleys. The ONLY part I didn't replace was the tensioner because it tested ok according to the manual.

I'll have to check my records and see if I replaced the tensioner a couple years back... I have a new crank pulley bolt to install, might be worth taking it all apart to replace the tensioner (although I think I did replace it) along with the crank pulley bolt...


hit a junk yard, grab a head and swap it out.... if the valve is bent and not broken, will a little damage to the top of the piston really be a big deal?