I was told that I need a new engine for my 1989 Jeep Cherokee with 237,840 miles on it. The cost is about $3,000 installed, and it will take five days. The company is reliable. The body is fairly clean, but the paint is fading. There are 5,000 miles on tires and lots of work is under warranty. Is there any reason not to install the new engine? If it lasts another 17 years, it will probably outlast me. I have other cars to drive during the repairs.

– Pat, Sunnyvale, Calif.

This situation has many aspects to ponder. First, you must be quite fond of the Cherokee or you wouldn’t be considering this. The cost of the engine job probably exceeds the value of the vehicle, and its resale value will be more related to its overall condition, including paint, upholstery and model desirability, than anything else.

Does the price quoted include engine mounts, belts, hoses, a new water pump and, perhaps, a starter and alternator? How’s the radiator, air conditioning, power steering and other under-the-hood components? Repairs to these systems or replacement of components is often done in conjunction with engine replacement as many of the parts are removed or scrutinized while everything is apart.

Another large issue is the transmission. Has it been overhauled, or does it seem to work flawlessly? If it’s the original, odds are that it will need work sometime in the future. The same goes for front suspension components such as ball joints, bushings and steering parts. The transfer case and front and rear differentials are amazingly sturdy components. Since they’ve made it this far, they’ll probably last another 237,000 miles.

I don’t mean to discourage you from replacing the engine, but I wanted to make the point that an engine makes up about one-fourth of the mechanisms in the vehicle. And while it is the most important and expensive component, it isn’t the only one that can wear out.

There are positives to this proposal, also. By keeping the Cherokee vs. purchasing a new vehicle, you’ll be saving a load of money in interest, depreciation, licensing fees and insurance. Another cost comparison might be that of a 5-year-old Cherokee, taking a look at mileage accrued and the risk of problems with it. Besides being in fresher condition, a newer vehicle also would provide greater safety, comfort, fuel economy and lower exhaust emissions.

Let’s say you do the engine job and drive the Cherokee another five years, with a few additional repairs before retiring it. That comes to about $2 per day. That’s quite a bargain, and it gets better the farther you go. Figure in a transmission rebuild, a couple of ball joints and some A/C repairs down the road, and it perhaps totals $4 a day. You’ll be upside-down in the vehicle at first, but if you’re sure you’ll keep the Cherokee at least a few years, your investment begins to pay off. Only you can make this decision, and it’s not just about dollars, but emotion.

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose. Send E-mail to [email protected].