Interesting thread. I'll use the estimate to impress the wife of my worth...
Seriously though, having been in the biz, and having had family in the biz, I thought I'd throw out some thoughts on honesty. There are definite cases at the endpoints, but the middle is fuzzy. So, consider the following:
You have a missing oil pan bolt. It is leaking a little bit of oil, but nothing that you have to even top off - you just notice some drips in the drive over a few months and take it in. You don't know what is wrong. You go to your local mechanic and here is the range of possibilities. They all probably happened to someone today, but they serve to illustrate the point without getting into technical discussions. In the following the car is taken 'round back, and the mechanic meets you after looking it over:
1- the mechanic (he from now on) explains the missing bolt, asks if previous work was done, says it isn't serious, but can replace the bolt if it's making a mess.
2- he replaces the bolt with a convenient one that works and passes the 'savings' on. (not the same as the chrome stud scenario talked about earlier)
3- he 'orders' a bolt, tacking on usual part markup, etc.
4- he tells you this one fell out, so all others need to be removed and inspected (more cost)
5- he tells you this one fell out, so all others need to be replaced
6- add to the above the pan needs to be removed and gaskets replaced
7- he tells you the pan and its bolts need to be replaced
8- 4, 5, 6 or 7 plus he cracks the gasket a bit to make it worse in case you want to go home and 'think about it'
9- he explains that the pan gasket leaks, and when that happens, several other gaskets need to be replaced too (not actually leaking in this case though) - maybe seals too
10- explains it's an oil pump leak (or similar) and will involve tearing down part of the engine
It can on from there, but I think we've defintiely crossed the line already.
A dealer will never do 1 or 2. 3 is pretty common, although if it's a good shop, 1 or 2 will happen. 4, 5, 6 play to FUD, and I've seen guys try to scare women that way saying it may not be safe, etc, when it's really overkill. A lot do that these days. 7+ are out of line.
Remember too, that this is a non-critical part that could be fixed with as little a $5 up to many hundreds of $ in the later cases.
There's also another dimension. While 1-3 only tackle the missing bolt, and 4 makes a big inspection deal of it, 1-3 can also be accompanied by the mechanic giving each of the other bolts a little tug with the wrench (not enough to break the seal) to verify another isn't going to come loose. A few minutes more, but it helps the customer and his reputation in the long run. That's not an honesty issue, but more of a 'professional' issue. Something the 18 yr old or lazy guy won't do. Even if it's $10 for the extra time instead of $5, it's a higher level of integrity.
-Skip
members and plenty of personal opinions;
