Changed my tb and all associated components back at 60K but my tb decided to explode after about 30K miles. I'm going to pull the head and swap it out with a remanufactured unit. Hopefully there's no bottom end damage. I was cruising at about 40mph when it happened.

While I have things torn apart, is there anything I should clean/replace/inspect?
Thanks!

 

Definitely check the pistons for impact damage - it's possible to create ridges that can become hot spots, which can increase the likelihood of detonation. Also, you have to figure out why the belt went. Is there a pulley or roller that's skewed or cocked at an angle? If so, that can keep the belt from running in proper alignment and tear it up. That's the most important part - figure out why it happened snd correct it so it doesn't happen again.

Otherwise, since you'll have some downtime, and you have a 1.8T from the sounds of it, drop the oil pan, clean it out completely, and clean/replace the filter screen on the oil pump pickup. Sludge can block it off and cause oil starvation, which will also kill the engine.

Do you have a few bucks to play around? You could gasket-match the ports at the intake and exhaust manifold gaskets, maybe see about smoothing out or enlarging them. I don't know how much this benefits the 1.8T, but I'm sure a knowledgeable 1.8T guy will chime in on that.

Since you're getting a new head, head gasket will be new. Likewise the valve cover gasket. Put in new cam seals too while the head is off and replace all your vacuum lines as well.

 

The heads not off yet but I did use a snake camera to peer in through the spark plug holes and noticed a half crescent imprint on each piston and I think 2 and 4 had some metal flakes sitting on top the piston. If the pistons are damaged, how much more involved does this job become?
Thanks for the quick reply.

 

The stock pistons may be scalloped (aka have valve relief cast into them), but I'm not positive. If so, that's what you saw. I'd think that the valves might chip or possibly gouge the piston faces but not actually cut them. Minor scoring can probably be sanded out but more serious damage means piston/ring replacement. That call is best left to an engine builder.

 

Damn, I want a snake camera....

 

http://www.harborfreight.com/wireles...tor-66550.html

I got mine at HF for $79 (normally $99). They go on sale once or twice a year, or just use a 20% coupon if you have a local HF.