There were short tempers in the Richard Childress Racing camp as well, with Kevin Harvick left fuming when early adjustments to the car left the #29 in a far worse state than when he'd started. The heated conversation with his pit crew got to the point where team owner Richard Childress himself came on the air and told them to just get on with it: ""We got what we got here, arguing ain't gonna get us nowhere!" he snapped.
Harvick's team mate Jeff Burton, meanwhile, was furious when he was placed by NASCAR behind Marcos Ambrose for the next restart, which was needed following a quick new caution when contact from Ambrose tipped Regan Smith into a spin. Even less happy about the incident was Smith himself.
"Ambrose is just driving over his head," fumed Smith. "I don't know if it is because he won last week, he's got extra pressure or what. He's been doing it all day. He's almost wrecked four times that I've seen. Unfortunately, four tyres are better than two, and I was four."
Ambrose was conciliatory when the two met up after the end of the race. "I feel terrible for him, I didn't mean to get into him," said Ambrose. "I got down in there and he came off my side of the car and I was trying to get out of there for him and just caught him on the way past. I feel bad for him. You can't take it back, all you can say is sorry."
Another quick caution came out on lap 89 when Joey Logano hit the wall in turn 3 on two consecutive laps and left debris on the track, and after a flurry of pit stops it meant that Truex Jr. led at the green flag ahead of Kenseth, Greg Biffle, Carl Edwards and Sam Hornish Jr.; Kenseth had a shaky moment into the first turn and temporarily dropped back several positions.
Further back, Jeff Gordon was also off the pace - and his engine sounded very sick. As well as Jimmie Johnson's Saturday engine change, Tony Stewart - also running a Chevrolet built by the Hendrick Motorsports shop - had suffered a valve spring issue affecting one of the engine cylinders. Gordon confirmed that the same fault had hit him, too.
"A valve spring, just running along there and all of a sudden dropped a cylinder," said Gordon. "The #14 had that same issue. Got our fingers crossed for all the other Hendrick engines out there - this is a tough place on engines. We rarely have these issues and it's unfortunate to have this one here today. It's the kind of year we have been having."
It was not the way he'd been hoping to follow up his race win last weekend. "I was hoping after Pocono we could carry some momentum and not have these kinds of back-to-back weekends, but that's not the case. We go on to Bristol and fight hard there."
Michigan is notoriously hard on engines, being flat-out for a higher proportion of the two-mile circuit than almost any other track that the Sprint Cup cars race on, but that was small consolation to reigning Cup champion Tony Stewart who spent ages in the pits trying to get his car repaired before finally having to concede defeat.
"I appreciate everybody at the Hendrick engine department," said the owner-driver. "We had three different engine tuners down there trying to get it fixed for us. It wasn't for a lack of effort. It's uncommon to have a problem like this."