When You Replace an Engine, a Little Pampering Is in Order

Reader Dave Duzy recently shared the story of his ’92 Jeep Wrangler and its long list of problems: overheating, excessive valve noise, a puzzling coolant loss (no leaks on the ground or water in the oil) and low oil pressure.

Some of it he solved himself (a can of Barsleak took care of the coolant loss), but the other problems, after much investigation, led him to one inescapable conclusion: time to replace the engine.

It’s too late for us to advise him otherwise--though based on the information he supplied, it sounds as if he made the right call. But for others out there facing a similar big decision, we offer Dr. G’s own list of engine swap dos and don’ts.

*

Any time major engine work is needed, from the cylinder head down to the crank, serious money is involved. If you own a vintage Ferrari, Jaguar, Porsche, Corvette or Mustang that isn’t rusted or has a frame that looks like a taco, the answer is simple: Replace the engine.

Most any other time, you have to evaluate several things if it’s out of warranty. Do you owe money on or lease the vehicle? Or is this the only means of transportation you have, especially to your job? If yes to either question, tough luck. You’ll have to take on more debt. Or take the bus. (That’s not as bad as you might think. Time to nap or read or flirt.)

If you own the vehicle outright, then consider these factors:

* Do you really like this car?

* Does it serve your needs?

* Is it in good condition?

* If the paint is shot or the seat springs are poking into softer parts of your anatomy, why put money into physical and financial pain?

* If you find this vehicle on Consumer Reports’ list of models or years to avoid, find out if the major engine work is the only thing you need to have done.

If it passes all those tests and you really love this car, consider the big swap.

If you decide to proceed, the most important thing to find out is whether there are good rebuilt engines available. A vehicle that started with a poorly designed, unreliable engine (and I’ve owned a few) isn’t likely to have good rebuilds available. This means you’ll want to find a shop that has done a few engine swaps on the car or truck you have.

You’ll want to get estimates from three or four shops. Consider the warranty carefully. Some are as short as three months or 3,000 miles. Others are closer to what you might expect from a new vehicle--four years or 40,000 miles.

Still, as good as any warranty is, the prospect of being without your car should post-swap problems develop isn’t all that pleasant. One shop that advised against a swap for my aging SUV described the time frame as being four to five weeks while any problem was checked out by the engine rebuilder. Again, you want to know if the rebuilt engine is going to be as close to new as possible in terms of reliability.

You’ll want to know if the shop’s price includes follow-up work, such as re-tightening the cylinder head (a must on any rebuild) and a cylinder compression check. In fact, it’s a good idea to have a compression check done on the new engine before you put any miles on it so you know what you’ve got.

After the fact, keep a close eye on oil consumption and get the first change done at 1,000 miles. And it’s an absolute must that the cylinder head bolts be re-tightened after 500 miles. The shop that did the work is a good candidate for this even if it’s not included in the price.

The break-in driving habits apply too: Vary your speed and don’t cruise for more than 10 minutes; no full-throttle starts; keep the rpm well off red line; and don’t go 85 mph. Do this for the first 7,000 miles and three oil changes, and you’ll extend the life of the motor appreciably.

Having seen quite a few post-1990 vehicles lately with smoky exhausts, I suspect a lot of people have ignored the break-in advice. With cars getting more expensive and smog standards tighter than before, this can be an expensive mistake.

*

Write to Dr. Gear Head, Highway 1, Los Angeles Times, Times Mirror Square, Los Angeles, CA 90053. E-mail: gearhead@latimes.com