On my way to the track this morning I was giving a friend a ride in my MK Indy R1 (2003 5PW). I was driving at 30-40mph in 4th, shifted down to second, relased the clutch and bang! Rattle, rattle, rattle, rattle from the engine.

It seems like my 2nd gear isn't feeling very well. The car runs just fine on every gear except 2nd where it rattles quite severely and vibrates

Second gear started missbehaving already on my last trackday where it felt like it sometimes lost drive for 0.5sec or so before engaging again. And shifting from first to second has felt a bit "crunchy" on rare occasions.

So two questions:

1. Is it worth the even trying to drive 200km home, avoiding second gear?

2. What's next? Might as well order a replacement engine right away?
This engine has done 26.000km and almost 5 years of trackdays but runs very well (apart from second gear) and hardly uses any oil.

If you are fairly sure a rebuild/replacement is needed anyway, I would drive it home and just avoid 2nd - quite easy in a BEC (although you will have to go into to 2nd to get to 3rd, but just don't engage the clutch!)....

Normally it is not worth paying a pro to rebuild it - I would swap the motor out for another, and then rebuild your old engine as a spare (or even add upgrades to it, so that you can drop in an improved lump at some point in the future).

A friend of mine had his 5pw 2nd gear start playing up just before leaving for a Euro trip. He did 2500miles with it avoiding second.

You might be OK or it might throw something through the casing.