Remembering why I
dislike working on
AO Silver Member
Join Date: Sep 2001
Usual issue with the early 24V slipping cambelt is at cold start, typically when the engine is raced on startup. The belt also drives the oil pump on this engine, so as noted, the wrap around the rear bank exhaust cam is woefully poor so they tend to jump one or two teeth. One tooth fine, it'll just run a bit rough. 2 or more...bent valve time. A good tensioner is critical...and you can't get new ones. If I was using one of those motors now, I'd probably opt for a static tensioner mod personally. Replace the tensioner with a bolt and locknut arrangment. Static tensioners on 12V motors have long been proven to work well - no reason why not on the 24V. Of course, ensure the ilder and tensioner bearings are in good order.
Waterpump is driven by accessory belt as on all Busso V6 engines, pumps are fine as long as they have a metal impeler, but it's always worth swapping it if you are doing the cambelt unless you KNOW it's only done limited duty. FWIW, I took the original pump of my old 155 V6 at 117k miles and it was just starting to get a bit grumbly so wouldn't have lasted much longer.
24V accessory belt idlers are hard/impossible to find as well I think. Not the end of the world, but just a bit more joy.....
Crank damper can delaminate, although it's rare. Keyway can wear as well, again, rare.
Valve guides and seals at big miles of course.
Seen more than one 24V with a shot bottom end. Seems to be something of a Busso weakness, or perhaps just poor servicing???
Typical Alfa thermostat issues of course.
Some parts getting hard to come by.
Probably about it I think....any more anyone??
Given a choice, I too would opt for the latest possible version - 166 or late GTV ideal. Or GTA of course....
That said, as long as the cambelt stays put, nowt wrong with the 164 24V motor.