[BB76]

When my car is in drive at a stop and the idle goes up & down causing the car to rev & jerk forward, does that mean my trans is slipping? I just bought this car a few months ago. It now has 65xxx miles. What should I do?

 

[Jjkalai]

It probably means you probably have a vacuum leak somewhere, your MAF is dirty, or your TB has a carbon buildup.

Thrown any CELs?

 

[BB76]

Thanks, I'll get that checked.

Also, what does it mean when it jerks as I'm accelerating - like when it switches gears..?

 

[karlt10]

Not discounting that you might need a fluid change, the items Jjkalai mentions could also cause your jerking symptom, especially a vacuum leak. A common problem on older cars is the air inlet tube between the filter and throttle body develop cracks along the accordion section. That would cause exactly the symptoms you are seeing.

 

[BB76]

So one of the vacuum hose were busted & I got it changed. The check engine light also reset. But now it's on again...could it be another vacuum hose cause it still jerks & does what I mentioned earlier...?

 

[MrTea]

did you scan to see what the code was?

there are 5 vacuum lines that attach to the manifold on the 03, plus the PCV hose under it, plus any cracks/leaks that could be in the intake system between the MAF and TB.

...so yes, it could easily be another line with cars as old as ours.

 

[flipper66]

did you scan to see what the code was?

there are 5 vacuum lines that attach to the manifold on the 03, plus the PCV hose under it, plus any cracks/leaks that could be in the intake system between the MAF and TB.

...so yes, it could easily be another line with cars as old as ours.

is this an I4 or V6?

take the car to parts store and have them read the code for you.

far easier to figure out why it is on if you do that, than us guessing.

 

[sp00n]

My 2003 6 seems to jerk hard into gear from the back of the car I hear a thump. Could this be my transmission or gear box? There is a whining noise coming from the engine that seems to get louder on occasions when idinling. I'm afraid to take it back to the Mazda dealer cause they wanted to charge me $750.00 to replace the thermostat and flush the cooling system. I overheated last week going to work in rush hour traffic. Just reached the 100K mile marker and apparently I'm stuck with this car forever. Any advise would certainly help.