Well, it's tough to say without knowing the history and the last time these things were serviced.
If it has never had a cooling system flush, then that is probably a good idea. You might be able to get a look at what is in there now to see how it looks.
Has the fuel filter ever been changed? If not, then 150K miles is over-due.
You did not say if it was manual or automatic transmission. For an auto, it needs the fluid changed every so often and a good flush there can sometimes correct hard shifts. For a manual, the gear oil should be changed every so often too.
Also, how do the belts look under the hood? Are any cracked, missing ribs, too much slack, showing strings? If any of those items are noted, then the belts need to be replaced immediately.