Mazda Help

[EricG]

Hi folks - my daughter started off to her sophomore year at NAU in Flagstaff AZ today. This is her first solo roadtrip and is breaking the 11 hour trip in half and spending the night in ABQ.

She's driving a 2006 Mazda 6, 4cyl, manual trans. It's been good mechanically, about 160k on the clock.

When I talked to her tonight, she's reporting that from about 1.5 hours into the trip she's had trouble accelerating in 4-5th gear/70-80 mph and some sort of bucking or vibration. She describes it as "bumpy" and can feel it through the steering wheel, etc. Says it smooths out around 85.

She said it was doing it on the level as well as hills. No check engine light and she wasn't watching the temp gauge.

Any ideas? Debating whether to have her take it in somewhere in the morning. Or possibly driving down myself and swapping her with my Corolla.

 

[CO_Hunter]

Could be fuel starvation under load? Smoothing out at 85 it could be downhill or flat and not under a load such as accelerating. The shaking steering is odd. I think I would tell her to slow it down as well

I went through a recent experience diagnosing a dead car my daughter was driving based on her symptom descriptions. Not easy and actually hard not driving it yourself.

Also have family in Santa Fe if needed.

 

[EricG]

I've been doing some reading and it sounds like a bad ignition coil may be the culprit. Found a forum thread that sounds very much like it. I don't think the steering is shaking like a wheel bearing or suspension problem. I think it's more like the whole car is bucking/shaking from misfiring and she feels it through the steering wheel.

I'm having her take it to the dealer down there first thing in the morning - not the route I'd normally go, but I figure it's the best bet to get her back on the road tomorrow.

 

[EricG]

Partial resolution...
So it turned out to be two separate problems. I believe the extreme vibration was caused by throwing a wheel balance weight - rim is apparently bent and took excessive weight to balance. Got it balanced out again and moved to the back axle. Will replace soon.
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Power loss is very intermittent - happened once between ABQ and flagstaff. And still undiagnosed.

You're right Leon - long distance diagnoses is hard. And she's not the best observer on this stuff.

 

[CO_Hunter]

Glad she is there safe and you can breathe a bit easier now.