Hello Looking at 456 ownership the issue with worn valve guides pops up on the radar. How common is this. Is It a disaster waiting to happen, an issue happened to a few cars and then blown out of proposion or affect some cars randomly? The car I am looking at is a 96 456 manual. Br Martin
I may be off base as I am picking my new to me 456m up next week, but from the mechanic who is doing some work on mine now, he stated that it is going to happen eventually due to the metal used on the valve guides. The problem starts to show up if the car starts to show oil smoke at start up. So it sounds like it isn't catastrophic, but will need to be addressed at some point as the engine use starts to add up over the years.
There were bad sets of valve guides mixed up with good ones during 456, 456M, and 550 production. Solved by going to sintered steel guides on the 575M and the late F355s, which had similar problems. Some cars got no bad guides (more brass than bronze) and some got a random number. Best thing to do is have a bleed-down check done to see if there is a problem. The bad guides can show up very early or much later (up to 45,000 miles or so), so no set pattern. There are 550s and 456s out there with high mileage and no guide problems, so it really is a crap shoot. You must be overseas because there are no US model 1996 456s.
