Should I be worried?

[mr.weatherman]

I have a loaded black cx-7 with about 16,500, I got it last June so yes I drive it a lot, 80% highway.

My issue, within the last month I noticed the tranny shift a lot more than usual on the highway between 5th and 6th, a lot of downshifts. I drive the same highway so it seemed odd that all of a sudden it would start shifting on me.

Next, when at a stop sign/red light and in drive, the car seems to get a little bit louder, when I throw it in neutral it goes away, almost like a metal panel or something is loose and vibrating.

MPG, I was getting about 22-23 mpg (driving about 70 mph) on the highway with no traffic (I work at 4am), THEN all of a sudden it shot down to about 15 mpg!!!!!

All of this happened right about the same time Valvoline rotated my tires, is there a connection?

Valvoline has been good to me over the years, I have been going there for about 10 years now, so I doubt it was something they did.

Any ideas?

 

[mikey1981]

Was it just a tire rotation? or did they change ur oil too? could be bad/wrong oil if this is the first time occurance.

They also could have rotated ur tires wrong, if u r seeing lke an 50+% decrease in MPG, tires could be fighting eachother. Bring it to the dealer

 

[mr.weatherman]

Was it just a tire rotation? or did they change ur oil too? could be bad/wrong oil if this is the first time occurance.

They also could have rotated ur tires wrong, if u r seeing lke an 50+% decrease in MPG, tires could be fighting eachother. Bring it to the dealer

They did change the oil, but it was like the 4th or 5th one there (I try to change it about every 3-4K), so I assume they know what they are doing.

About the tires, I went back and asked them if they did it right, they looked/pulled the front ones off and all was well.

It has also been cold here in New England the last month, right about when it started happening. so maybe my car does not like the cold?

 

[mikey1981]

I live in newengland as well. If you are talking about the vibration, does this vibration go away during your driving? When it has been REALLLY COLD like 10 to 20, theres a vibration that vibes for a few seconds then goes away for a second or 2, then repeat, kinda like a fan or the ac was running, except you can hear and feel it in the stearing wheel . . .thats been the only thing i have noticed in the cold weather, but it goes away if u let the car warm up for a little while or after driving it for about 5 + mins. Freaked me out the first time cuz it comes right up thru the steering wheel. But it did/does go away.

The cold has not affected my MPG, i actaully see an increase, if anything

If all this has happeend right after this service visit, i dunno sounds like they mighta did something but who knows

 

[TheMAN]

bringing your car for a $20 oil change at those "quick lube" places, and that's what you get... $20 of "service"

more than likely, they didn't put in the right oil and the right amount of oil in your engine... I've seen it happen all the time on the ms6s because they think it's just a normal 6 and they put in the bad oil in it and only the amount for a non-turbo 6... no reason why it wouldn't happen on a cx7

anyhow, your shifting issues are caused by computer issues... search for the hesitation issue and you'll find details about it... mazda knows about it and it is covered under warranty

 

[mikey1981]

yea, its def gotta be the oil, maybe the kid or guy just put in the wrong one, or just assumed whatever tehy had would work.

ur issue def sounds related to the service visit, and nothing more than that, id goto the dealer, flush whatever oil is in there, get a real oil change, and then see what happens. Only way you will find out.

 

[kailua]

I don't know about crappy oil, but it could be the wrong weight. I think ours is recommended to be 5w30. The lighter the weight the better the fuel economy, usually, less viscous.

It could also be bad gas. I notice a difference in the performance of my vehicle depending on which station I fill up at. Everyone's "premium" unleaded is not the same.

 

[mr.weatherman]

I don't know about crappy oil, but it could be the wrong weight. I think ours is recommended to be 5w30. The lighter the weight the better the fuel economy, usually, less viscous.

It could also be bad gas. I notice a difference in the performance of my vehicle depending on which station I fill up at. Everyone's "premium" unleaded is not the same.

The vibration only happens when stopped/red light and in drive, when I throw it in neutral it goes away.

I have experimented with different gas brands and that does not help, I usually go with exxon/hess/shell.

I also tried driving about 60 mph instead of 70-80mph, and that did not really help, got about 16mpg out of that full tank.

It would be a 1st if valvoline screwed my car up, cuz I have been going for years, took my Jeep there for 6 years from new to 125,000 miles and never a problem but there is always a 1st.

I had a shifting problem with a saab 9000 once, it turned out to be one of the hydrolic motor mounts went bad, causing the engine/tranny to tip to one side by a matter of inches and that was enough to throw the tranny off.

I was thinking maybe they screwed something up when they lifted the car up to rotate the tires, perhaps a motor mount?

 

[mikey1981]

Shell V Power has yielded the best results so far in new england thru my travels and is the most consistent with MPG

It really sounds like somethin happened to ur ride while ur car was at that service shop. Maybe it fell off a lift, maybe they did something to the frame, the list can go on n on,

like i said before, u want a straight opinion, the worst thing u can do is bring it back to the guys who may have potentially done something to the car, if u know what i mean, regardless of how long youve been going to them, im sure they arent going to admit if anything went wrong

bring it to a Mazda dealer