One Stop Engine Rebuilding is owned and operated by three Lopez generations including (from left) Oscar, his father Wilson, his father, Julio and mother Marcela, Wilson’s brother, Christian, and Wilson’s wife and office manager, Marcela (not pictured).Oscar Hernandez uses the shop’s Axe pressure tester to reveal the tiniest leaks or pin holes in an engine block.Technician Christian Lopez works on an Audi engine with a bad timing chain tensioner. Jose Jimenez, journeyman machinist, cleans an engine by hand, which One Stop Engine co-owner, Wilson Lopez, says is the best way to make sure nothing is left unclean, which can happen in a media blasting process. Julio Lopez, co-owner and Wilson’s father, sets up the shop’s Rottler boring and sleeving machine.

One Stop Engine starts with quality

Hawthorne, Calif.—One Stop Engine Rebuilding opened its doors 14 years ago, but the multi-generation, family-owned business actually began in Honduras about 45 years ago, co-owner Wilson Lopez said.

“My father, Julio, got into the trade in Honduras at the age of 14, working at a machine shop during the day and delivering newspapers at night,” Lopez said.

The family moved to the U.S. in 1985 and Julio and a partner opened an engine rebuilding shop, which he ran for 14 years before deciding to leave it and open One Stop Engine Rebuilding with his son, Wilson, and Wilson’s wife, Marcela, who is the office manager. Wilson’s son, Oscar, has since joined the staff.

“Through the years, I had worked with my dad, who shared his knowledge with me, so I would know how to be successful,” Lopez said.

For the first seven years, the shop focused primarily on repairing and rebuilding engines for wholesale customers, so the shop was equipped accordingly, including a Rottler boring and sleeving machine, Rottler head and block surfacing machine, Sunnen honing machine, Sioux valve face grinder, and an Axe pressure tester. 

“We magnaflux blocks to find obvious cracks, but we use the pressure tester for blocks because it’s the best method of testing for cracks, especially in areas that are not visible, like under the valve seat or half way down a head bolt hole,” he said.

The shop also has hot tanks, and a media blast cabinet for cleaning blocks, but he prefers to clean them the “old school” way — by hand.

“We have a journeyman machinist, Jose Jimenez, who does all of the engine cleaning by hand to make sure it’s completely clean, and our customers appreciate our attention to detail,” he said.

When a customer comes in or calls for engine work, Lopez has a list of basic questions he asks before any work is done.

“For example, how long ago was the vehicle purchased? Is it leaking oil? Is there any history of overheating? Questions like that make sure no problems repeat from the past.”

The shop specializes in stock engines and doesn’t do performance engine work. Parts are bought from Don Gross Warehouse, WORLDPAC, IMC, and Egge Machine Company.

“We also do a lot of original engines in older vehicles that customers want to keep, such as the 1950 Olds 98 with a 303 V8 in the shop now, so we buy a lot of parts from Egge,” he said.

About eight years ago, the shop added mechanical repair, including suspension, brakes, and oil changes, when they saw the demand from customers.

“We have ASE-certified technicians who can perform the work, so it became an additional source of revenue for us,” he said.

Customers were pleased with those services, and they began to ask them to do routine checkups and other services. “So we purchased Snap-on and MAC scan tools to handle the diagnostic work.”

Training is ongoing and includes technical services bulletins (TSBs) from manufacturers and vendors, and from the Automotive Engine Rebuilders Association (AERA), which Lopez said provides a wealth of information and services.

The shop doesn’t perform fleet service, but it does wholesale work for local auto repair shops and offers free pickup and delivery. About 80 percent of its business is still engine rebuilding and the other 20 percent is general auto repair and maintenance work, Lopez said.

Car count ranges from 15-20 cars per month, primarily because of the time it takes to remove, rebuild, and reinstall an engine and he is happy with the workload.

“We believe in quality versus quantity, that’s how we can offer a 12-month/12,000 mile warranty, but there has been a steady increase in business year-over-year, amounting to 15 percent,” he said. “Mainly because of customers’ needs and great referrals.”

Today’s engines are very hi-tech, but Lopez has found that more often than not something as simple as not following proper oil changes is the cause of engine problems.

“Although many newer vehicles will expand the traditional 3,000 mile or six-month interval to 4,500 miles, we find that many of our well-intentioned customers can’t find time during their busy days to have this critical service accomplished — a side effect of living in Southern California.”

Near future growth plans for the 4,400-square-foot shop with a 4,400-square foot lot include installing two additional lifts, and adding an additional technician or machinist.

“In addition to a rebuilt engine being cheaper than buying a new one, let’s not forget that rebuilt engines help the environment,” Lopez said.

Parts & People

Parts & People is published monthly by Automotive Counseling and Publishing Company, Inc., a Colorado corporation, P.O. Box 18731 Denver, CO 80203, 303-765-4664. President-Lance Buchner. Founded by Lance Buchner and Dave Lucia.