Stump the chump...Can you figure it out

I’m a mechanic at a Nissan dealership in Baltimore, before that I worked at a GM dealership for 10 years. I have come across some weird problems, from bad smells on left turns and a dvd player that only played Jungle Book no matter what dvd was inserted(Multi-DVD changer not working). However the clicking noise I’m about to describe on a 2005 Malibu is the most difficult diagnosis I had to make, and I want to see if it is just me or if the problem is unique.

As I previously stated, the car is a 2005 Chevy Malibu with 45,000 miles and a 3.5l V6. It came in for a clicking/tapping noise on hard right turns. The frequency of the tapping was somewhat independent of engine/vehicle speed, but you had to be going fast enough to take a hard right, say 10-15 mph while cutting the wheel hard. Increasing RPM only increased the tapping frequency slightly. The axles were good, there were no suspensions or internal engine issues.

The one hint I will give is that I had to remove the Torque converter cover (as if I wanted to remove the converter bolts) to figure out what was happening. I’ll chime in with the answer after a few posts, and I appreciate anyone who plays along with me, its just one of those things that drove me crazy for a week and I’m hoping its somewhat difficult for anybody else.

Flex plate?

Starter drive gear loose contacting flywheel on turns.

My guess: I think the starter motor was permanently engaged for some reason, like the solenoid was stuck on. The car will still work ok like that as it has an over-running clutch like gadget, so the starter motor just spins and spins but isn’t spinning anything of import. The teeth remain engaged though. But somehow the forces when turning right on the starter/flexplate teeth make the situation worse and that’s what was making the sound.

Seeing as how everyone else has hit the flex plate, starter motor theories guess I have to come up with something else.

A slightly loose torque converter attachment bolt.
Converter cover deformed and converter hitting the cover.
It’s been off before and someone inadvertently left something in it.

There’s my wild guesses… :smile:

Starter theories are correct. Spring was broken, not holding the starter gear back, so on hard right turns it would contact the flex plate. When I took the cover off to see if the flex plate/converter were causing the noise I saw a bunch of marks on the plate. Then I saw the starter spring broken, allowing the gear to slide back and forth unimpeded.

I wish I had a few of you guys working next to me, would have save a lot of headache!

hey asemaster, have you run into this before, you hit the nail right on the head! OR was it my Superior descriptive abilities giving too much away?

However, since I’m full of myself it probably has more to do with your abilities :slight_smile:

It’s not an uncommon problem, after you figure it out the first time you remember the noise and go right to it.

Customer complaint of tinny rattling noise when driving uphill, in a Chevy pickup. Starter drive would slide rearward and hit flywheel.

“Increasing RPM only increased the tapping frequency slightly”

What is the explanation for this seemingly anomalous behavior?

because the force of the impact at higher speed knocked the gear back far enough not to hit every time?

Good call @asemaster ! Spot on.