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rpmdiag, Tech and Instructor
Category: Mazda
Satisfied Customers: 8059
Experience:  Since 1975
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2007 Mazda 6 shudders at 45 mph more so if going up ll

Customer Question

2007 Mazda 6 shudders at 45 mph more so if going up hill
Submitted: 1 year ago.
Category: Mazda
Expert:  rpmdiag replied 1 year ago.

Hi, I’m Ron and I can help you.
I have been in this business since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. Please be patient!
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

The first things to do are to check for codes in the computer, then test fuel pressure and volume. Some sensors can cause this, and the scan tool will help us here. Low fuel pressure can also cause this.

Thanks, Ron

Customer: replied 1 year ago.
There are no service codes available no service engine light.
Customer: replied 1 year ago.
Does this car have a changeable fuel filter?
Expert:  rpmdiag replied 1 year ago.

Great, you still need to address my other suggestions.

Thanks, Ron

Customer: replied 1 year ago.
I have good fuel pressure and no codes
Car runs absolutely great on acceleration and only jumps at 45 to 55 when under a load
Customer: replied 1 year ago.
low RPM when you hit a grade in most case
Expert:  rpmdiag replied 1 year ago.

Did you check the pressure with a gauge? If you didn't, then you have no idea what it actually is.


Customer: replied 1 year ago.
will you tell me where the fuel filter is on this model car
Customer: replied 1 year ago.
why do you think it is fuel pressure and what would cause it to be low
Expert:  rpmdiag replied 1 year ago.

Your fuel filter is either in the supply line on the frame or in the fuel tank. Fuel pumps fail all the time, and by your complaint, that's what it sounds like to me.

Thanks again, and please don't forget to rate me and keep this link for future reference in case you need me again later on.