What seemed like a robust car early in Sunday's race at Auto Club Speedway began to cough and wheeze. Hamlin couldn't diagnose the ailment. He radioed Ford that he thought an electrical issue sapped his car's power. Ford said it sounded as if the engine dropped a cylinder.
When Hamlin limped to pit road, the diagnosis was grim. Hamlin's crew pushed the car to the garage, where an evaluation soon turned into a postmortem.
This has been a recurring nightmare for Joe Gibbs Racing. A team that won more Sprint Cup races last season than any other has suffered more engine problems than anyone else this year. Winning no longer is the main goal for Gibbs' teams.
"We need to prove at this point we can finish a race,'' Hamlin said.
The troubling trend started in Daytona, where Hamlin's team changed engines before his qualifying race. At Phoenix, Joey Logano blew an engine. At Las Vegas, Hamlin's team again changed an engine before the race and Busch blew one during the event. No engines blew at Bristol, but Logano complained during the race about a sluggish engine. Then came Sunday's race, during which the motor maladies of Hamlin and Logano overshadowed Busch's third-place finish.
Hamlin said the issue with his engine appeared to be in the valve train and similar to what caused Logano's team to change engines Sunday morning. It's unnerving to a guy who challenged Jimmie Johnson until the final race last year for the championship.
"I'm worried a little bit more,'' Hamlin said of his motors after finishing 39th -- the third time he's placed 20th or worse in the season's first five races. "We definitely need to get some solid finishes.''
He's fallen 13 spots in the points in the last two races. Who knows how far he'll drop if JGR can't find what is crippling its engines. Hamlin said there hasn't been a common thread among the blown engines this season. That's made it more challenging for Gibbs' team to fix.
"It's not that you'll find something and maybe get it fixed in a week,'' Busch said. "But we certainly wish we would have been able to get it done by now.''
Even competitor Richard Childress has compassion for the Gibbs engine department. Childress' cars have blown three engines this season and he vowed to help.
"We think we know what it is,'' he said of his team's early engine woes. "Gibbs has had a similar problem. We'll be working with them, try to tell them what we think our problem was and maybe it will help them as well.''
With Hamlin 21st in points and Logano 29th, help can't come fast enough.
Tony Stewart saw another victory turn into a disappointing finish Sunday. He was third on the final restart with nine laps left before his car rebelled and went backward, finishing 13th.
What caused Stewart's slide? "Not sure,'' crew chief Darian Grubb said as he walked out of the garage. "We just can't take off, whether we take two tires, no tires or four tires. I really don't know.
"We stayed out [earlier in the race] when everybody took two tires and we were able to take off and fly with it, so we were kind of doing the same thing at the end there and it just didn't work out this time.''
This adds to a growing number of near misses for Stewart, who could list Victory Lane as a permanent residence if he'd had better fortune this year.
-- His troubles began in the Daytona 500, a race that teases and torments him. Stewart was second on the final restart, but he and drafting partner Mark Martin failed to make a strong run and Stewart plummeted to 13th.
-- Pit strategy put Stewart in the lead at Phoenix until a late caution ruined the ploy and he fell back to seventh.
-- He led the most laps at Las Vegas but a penalty for dragging equipment out of his pit box ruined his chances to win. Although he rallied to finish second, the result left him hollow.
-- And then came Sunday's stomach punch.
So, how do Stewart and his team move forward?
"Keep trying to kick their a--,'' Grubb said. "We're doing it all day long. We've just got to finish there.''
The duck pond may be gone, the train tracks beyond the backstretch relocated and new bathrooms installed, but many things remain the same at historic Martinsville Speedway.
Jimmie Johnson and Denny Hamlin dominate.
As the series heads to Martinsville this weekend, no driver other than Johnson and Hamlin has won a Cup race at that track in five years. That's nine consecutive wins for the duo with Johnson scoring five and Hamlin four -- including the last three in a row.
"The world at Martinsville does not turn upside down as fast,'' says Steve Letarte, crew chief for Dale Earnhardt Jr.
He's talking about setups where there's little change from year to year -- just like the hot dogs there. Technology doesn't play as big a factor on the circuit's shortest track.
If ever Hamlin needed to see history repeat it's now after his early-season struggles. "Martinsville spring race always seems to be the springboard for our season,'' Hamlin said. "We're looking at that race track in particular to be the one that kind of sets our season in motion.''
It's rarely disappointed him. He and Johnson have finished 1-2 there three times. They've combined to lead nearly half the 4,519 laps run at the track during the stretch.
Certainly, Hamlin has had the edge on Johnson lately. "We probably don't have the dominant car that we had there in years past as other teams have caught us,'' Johnson said. "We just need to find a little something there. A little bit goes a long way on a smaller track like that.''
Even so, for as competitive as the sport is supposed to be, how can two drivers dominate one track?
"I think once those guys know the feel that they want and then know the feel they have to have at the end of happy hour to be good for the race, I think that's a big factor,'' said Stewart, whose victory in the 2006 spring race is the last time a driver other than Hamlin or Johnson won a Cup race at Martinsville.
"We had a run there where we didn't win a lot of races there, but we were very consistent and ran a lot of top-3s and top-5s and I knew exactly how I had to have my balance at the end of the session to be good for the race."
The driver who has come closest to beating Hamlin and Johnson is Jeff Gordon, a seven-time winner at that track. Gordon has eight top-5 finishes during the reign of Hamlin and Johnson. What could be different this year is that Gordon enters with a new crew chief, Alan Gustafson, after the offseason changes at Hendrick Motorsports.
"He's inspired me to work harder,'' Gordon said. "He's a very smart guy and he works really hard, and I want to give him everything I possibly can. It doesn't change how I diagnose what I need. Those things are still the same, it's really more about how they plan to fix those issues or address those issues."
The question is if that will be enough to beat Hamlin and Johnson this week.
Dustin Long covers NASCAR for The Virginian-Pilot in Norfolk, Va., The Roanoke (Va.) Times and the News & Record in Greensboro, N.C. His blog can be foundhere. He can also be found on Twitter.