[budtee]

I have a 2002 300M with 65,000 miles on it. I believe that timing belt is supposed to be replaced in 7 years or 100,000 miles. Almost 10 years old but only 65,000 miles. My wife drives it and likes it. (That makes one of us.) It is an interference engine and failure would probably be very very expensive. I would not hesitate to change the one in my 2.2 turbo but one look at the 300M convinced me that I did not want to attempt it.

How much of a risk am I taking? Any idea what a dealer would charge to do it? I hear that the water pump should be changed when that is done also.

I am trying to convince the wife to get a new car and l am looking at the cost to keep it. ( Also needs a TSB done and possibly an oxygen sensor. Also, the air bag light goes and comes and that will probably be expensive. Those issues dealt with in a separate post.)

Would appreciate any advice.

 

[ImperialCrown]

The TSB (PCM flash) and seat airbag repair may be best handled by the dealer-only.
The timing belt/water pump/idler pulley replacement may be done by the dealer or at an independent shop. Some dealers try to keep cost competitive for things like timing belt service and consider it desirable 'gravy' work. There may be a set price for 3.5L timing belt maintenance that is reasonable.
The PCM flash is fairly easy and they only have to plug in the DRB III scan tool once for that and the airbag fault diagnosis. Remember that there is a chance that you still may need a fairly inexpensive O2 sensor if the fault code returns after this.
Ask for an estimate total and go from there. There will be a diagnostic charge (which is likely their minimum charge) and if the seat has to come out and apart it could get more expensive, especially if it is determined that the seat airbag assembly itself ($$$) is in need of replacement. We just don't know at this point.
Hopefully they may find just a bad airbag electrical connection in which case the charge would be mostly a reasonable labor time charge.
If you give the OK for the work, the diagnostic charge will go towards the bill.
I can't say yes or no. Determine the condition of the rest of the car and how well it has served you up until now. How much would it cost to replace? Would you sink up to $1000 or possibly more into it?
It is a low mileage, premium model and the wife seems happy with it. Talk over the positives or negatives with her and weigh the 'fix it or trade it' options open to you financially and otherwise for the next couple of months.
Many dealer new car sales are made when the service bill estimate to fix the old car get too high. A low-mileage premium 300m is still a nice car even if it needs fairly expensive work. At 10 years old, all repairs should be considered maintenance.

 

[JA Cumbo]

I had mine done for around $600. I supplied the belt and tensioner and a water pump.

 

[budtee]

I had mine done for around $600. I supplied the belt and tensioner and a water pump.

Was it done by a dealer or independent?

 

[Tweety Bird]

I did mine myself and it wasn't as hard a job as it looked like it would be.

But I'm an airline mechanic by training and an airline maintenance instructor by profession, so I don't hesitate to jump into any job (even my co-workers thought I was nuts to rebuild my own TorqueFlite several years ago, but they're cowards ;-) )

If you have good mechanic skills, it can be done in your garage. But if I'd thought I could have had it done by someone else for $600, I wouldn't have thought twice about taking it to the shop.

Your call. But replacing the water pump (and, IIRC, the belt tensioner) is smart because if they fail next month, you'd basically have to do the whole job again.