ANN ARBOR, Mich. -- Jim Harbaugh insists that Michigan is hitting its stride on offense, apparently seeing what observers outside the program are missing.

The Wolverines were held scoreless for the final three quarters of a 10-3 win over then-No. 14 Iowa and appeared to affirm doubts that they can have success with the ball against quality opponents.

No. 16 Michigan (4-1, 2-1) might be able to put together an encouraging performance at Illinois (2-3, 0-1) on Saturday, as it did in a 52-0 win over Rutgers last week, but ranked teams await in the second half of the regular-season schedule and will provide tougher tests.

The Wolverines have games coming up at No. 10 Penn State, against No. 9 Notre Dame and against No. 3 Ohio State, along with matchups against rival Michigan State and at Maryland.

To reach their goal of winning the Big Ten title for the first time in 15 years, the Wolverines' margin of error is small, and that adds a sense of urgency to improve with the ball under first-year offensive coordinator Josh Gattis.

Harbaugh hailed the hiring of Gattis and raved about the no-huddle, spread offense the former Alabama assistant was going to be in charge of without interference. Gattis began calling plays, for the first time, from the press box before he moved to the field for the previous two games.

With the coordinator up high and down low, the results have been uneven at best. Big plays have been few and far between.

Shea Patterson threw a 51-yard pass to Nico Collins on the first play of Michigan's second drive against Iowa. For the rest of the afternoon, a play wasn't called to throw deep, or Patterson didn't have time to go long.

"We just stayed patient and took what they gave us," Patterson said after the game.

The running game also was not very effective, with freshman Zach Charbonnet leading the way with just 42 yards rushing, barely averaging more than 3 yards per carry.

"There are still some things we gotta clean up, but they weren't detrimental," center Cesar Ruiz said Saturday.

Even though Michigan's defense forced four turnovers, its offense was able to score only three points on ensuing possessions.

"We left a lot out there," Patterson said.

Problems passing and running have added up to lackluster results.

The Wolverines rank among the bottom half of teams in the Big Ten in scoring, rushing, passing, sacks allowed, third-down conversions, red zone offense and turnovers.

Patterson had the third-lowest quarterback rating of his career against the Hawkeyes and three of his worst games, statistically, have happened this season. Michigan hasn't had a running back reach the 50-yard rushing mark in three games. It went into the season touting three receivers -- Collins, Donovan Peoples-Jones and Tarik Black -- but none of them has consistently clicked with Patterson in an offense that hasn't lived up to its speed-in-space billing.

The offensive line has not become a position group to count on, even though it has four returning starters, all of whom earned some level of All-Big Ten recognition last season.

Harbaugh has said, repeatedly, that it's all good when his team has the ball.

"I feel like we're very close offensively and very close to hitting our stride, hitting on all cylinders," he said. "Really good evidence to back that up and also what I see."