ZDDP in used cars

[Garak]

Originally Posted By: BrocLuno
GM could really shoot themselves in the foot trying to save a nickle ...

Given the short warranties of the day, GM did dodge a lot of bullets.

 

[Scdevon]

Originally Posted By: Garak

Given the short warranties of the day, GM did dodge a lot of bullets.

I was a dealer tech at a multi-franchise GM shop in the early to mid 1980s and we replaced dozens of 305 camshafts under warranty. Our Rep would goodwill almost all of them that were out of warranty within reason.

I remember GM's warranty back then being 12/12,000 bumper to bumper and 2/24,000 on the powertrain, then the powertrain warranty went to 3/36,000 I think.

 

[Garak]

That's not so bad. The taxis usually went beyond warranty period, significantly, before the 305s were lunching cams. On the other hand, even if they were getting to the point of replacement, it tended to be simpler and faster (and therefore more cost effective, with less downtime) to get the parts and do it ourselves, rather than do much at the dealer. In all the years, I can only think of one time we made a warranty claim, something to do with the fueling of the 1986 Caprice. I can't think of any cam replacement in the taxis that happened under 75,000 miles.

 

[Scdevon]

Originally Posted By: Garak
it tended to be simpler and faster (and therefore more cost effective, with less downtime) to get the parts and do it ourselves, rather than do much at the dealer. I can't think of any cam replacement in the taxis that happened under 75,000 miles.


We saw bad cams well before 50,000 miles at the dealer. Some of them never went bad. Gm used that 305 in lots of stuff, too.
The service bulletin instructed you to add a can of EOS with a cam / lifter change. GM EOS must have been loaded with all the good stuff back in the 80s.

 

[dave1251]

This "issue" is predominately a GM issue. GM will destroy its reputation to save 7 cents a vehicle such as it's LIM gaskets.

 

[Garak]

Originally Posted By: Scdevon
We saw bad cams well before 50,000 miles at the dealer. Some of them never went bad.

That's interesting to hear. I guess we dodged a bullet that way, in that they lasted a while before going bad for us. Then again, taxi service has few cold starts. Most of the cabs were 305s. EOS is still around; I don't know how different it is, though. We never bothered with it back in the day. Cam and lifters replaced, no problems thereafter.

 

[Truckedup]

GM also had a rash of bad cams in the 1970's, 350 Chevy engines and Pontiac...At that time I believe GM used an outside manufacturer to make cams..The problem was improper heat treating..