So for some while now my engone has been getting worse and worse..at 1st it just took a little longer to take off and gas was a little worse..but now its way worse, i hear some rattling noise comming from the engine, it REAL loud..at 1st it was just on the take off for a few seconds, but not its even when im going around 70mph..eveyr time it rattles it makes like a jerking motion and the car slows down. Also now that noise can last up to like 20 secs and its feeling like crap. Earlier I was going up a bridge with the cruise on @ 75 and then i noticed it started to rattle again and it slowed down to 65 before the rattling stopped and it slowly sped up again..and finally when im in idle the arrow moves from 750 to 1250 for no reasson...

my car is a 05 AT with 56k miles on it and no engines mod except for a k&n drop in filter..oil is 5w30 penzoil and i do regular maintanace on the car.

 

when was the last time you changed spark plugs and coils?
when the problem happens, any check engine light flashing?

 

Thought about those Jason.........but something tells me this might the the clogged CAT.
Of course................then the questions is.........if CAT, then did bad coils/plugs lead to it?
Yeah, I sort of wondered why he didn't mention a CEL either?????

 

Sounds like detonation. Coils plugs and wires are in order on an 05 with 56k if they are original. You can pick up the parts and do it yourself for $300-$350.

+1 on the cat as a possibility but it's probably worth doing the coils first. Although if you are able to jack up the car it's worth inspecting the inside of the cat first as this would be free to do yourself before you drop $350 on ignition.

 

well i just got the car like 5 months ago and i do think everything is still the original crap..i got an appointment in 3 day at a good mazda dealer here in town for a diagnostics and a complession test but i wanna know if anyone has had this problem before i give the dealer 200 bucks 2 just check my car..lol..and about the wires and plugs and all that, im thinking about the BHR kit since ive heard it helps alot

 

also every now and then i hear a loud backfire from the exhaust, not the normal ones from when u let off the gas real quick and stuff but a louder one

 

and no i have no CEL on

 

Agreed. A rattle under my car ended up netting me a free new cat!! At 60k.

No other issues!! No CEL.

 

how do u get a new cat for free?

 

the car comes with a 8 year emission warranty.
the dealer will test the cat see if replacing is necessary.

 

nice to hear a free cat...

 

oh ok..cool cool..and yeah im not gonna get the compression test anymore, im just gonna get the regular diagnostics

 

To be more specific, it is 8 yrs/80K miles.

 

im still able 2 get that! hell yes!

 

The loud backfire you hear is most likely unburnt fuel getting ignited on the way out in the CAT.

This is MOST likely to be due to bad spark of the plugs or coils. This in turn takes out the CAT over time.

Since the CAT would be free as others have said for 8 years or 80k miles, have them check that and obviously the coils/plugs. The BHR system isn't a magic pill, but it's damn good!

Even if you decide to stay with OEM coils, get them online with the plugs and do it yourself and you will save a ton of cash!

 

+1 exactly.

 

yea im gonna do it all myself i just need the dealer 2 look at it 2 see exacly whats wrong before i start buying things i dont need..and yeah im gonna get that BHR ignition and the soark plugs they sell there 2

 

Well.........have the dealer check the CAT and if bad, get your free one!
I wouldn't run the "new" CAT until you get the coils/plugs squared away.

 

ok, thanks!

 

do update us on what was diagnosed...

 

i will..can goes in 2morrow and ill let yall know what they tell me..then ill start fixing it and updating yall

 

oh and another update is that my car hassent done that jerking motion since i posted this..

 

see. Just talking to us solves your problems!

 

yes it does..lol..its like im going 2 therapy for my car.lol

 

Naw.....it really cause it's scared of us!!!!!!!!!!!!!!!