Car Shaking/Sputtering

[dyang1]

I need help guys. When I first bought my car a month ago it was slightly shaky when at the lights or stop sign. My brother in law threw in new spark plugs and everything seem to mellow out.
Just this past weekend it started to shake violently at stop lights. The rpm drops dramatically too when letting go of the gas pedal while driving. That one thing that plugs into the car shows up P0300, something about cylinder misfiring. Anyways, I just got it back from the shop today but it's still doing the same thing and the check engine light came back on. They put new spark plugs and ran a 3 fuel cleaner package thing in to my car. They didn't put new wires cause they didn't have any that fit. I brought up to them something about a coil pack and he said since when I drive it's normal, it's no the coil. $170 and nothing changed

Should I just take it to the Mazda dealer to get it fix? I don't want my car dying on me.

 

[hoanmy]

I need help guys. When I first bought my car a month ago it was slightly shaky when at the lights or stop sign. My brother in law threw in new spark plugs and everything seem to mellow out.
Just this past weekend it started to shake violently at stop lights. The rpm drops dramatically too when letting go of the gas pedal while driving. That one thing that plugs into the car shows up P0300, something about cylinder misfiring. Anyways, I just got it back from the shop today but it's still doing the same thing and the check engine light came back on. They put new spark plugs and ran a 3 fuel cleaner package thing in to my car. They didn't put new wires cause they didn't have any that fit. I brought up to them something about a coil pack and he said since when I drive it's normal, it's no the coil. $170 and nothing changed

Should I just take it to the Mazda dealer to get it fix? I don't want my car dying on me.

Holy hell this brings back bad memories for me friend. Please check the following items and if they all fail then go to the dealership, if you're still under warranty.
1) check the air filter (is it dirty or loose)
2) Check the intake tube and it's connections to the throttle body and air filter. Check the air temp sensor and mass air flow sensor for carbon build up or loose connections. The air temp sensor looks like a plastic chess piece and it's near your air filter's box. the mass air flow sensor is on the intake tube and it's the square box thing right where your air filter meets the tube.
3) clean or fix any minor issues here. if the filter's dirty then that's most likely your main culprit.
4) if the idle is still wierd you can clean the EGR (in the how to) and this fixes a lot of the idle issues.
In my case i had problems with all of the components listed above. let me know how it goes.

 

[jtlinna]

P0300 random cylinder misfire. Id do a search as this happens alot around here.. things like EGR and MAF and the coil packs are the places to start IMHO. I just got done dealing with this. Turnd out to be my coil packs.. AND NO they wouldnt act up while i was driving.. Only at idle.. i strarted changing plugs and wires, cleaning the EGR. didnt help. then went to the coil packs and BAM!! Fixed.

P0300 is a pain in the ass problem. Alot of the guys that bring them into shops seem to end up getting parts they dont need trying to chase down the problem. AT $170 your on your way to being in that club! Nine times out of ten its the coils or EGR. I suggest doing a search and take a day to read up on here about what everyone has done to fix this code.. It will greatly help you in making an informed decision about what to do next.

good luck
JT

 

[dyang1]

Thanks guys, I think I might try with the coil packs first. How much does that cost anyways, with the way the economy is going, I don't have much money to spare on fixing my car, but I guess I have to find money somehow. Is the coil pack under $100? I might just have someone who knows something about cars put it in. The shops charges too much.

 

[SocialStealth]

Thanks guys, I think I might try with the coil packs first. How much does that cost anyways, with the way the economy is going, I don't have much money to spare on fixing my car, but I guess I have to find money somehow. Is the coil pack under $100? I might just have someone who knows something about cars put it in. The shops charges too much.

Clean the egr valve first. And sea foam your engine. This will cost you maybe $5-$10, take only a few hours to accomplish, and more than likely solve your problem.

where are you from?

 

[echofall]

I would also suggest coils or egr as I had problems with that, but from what you described it reminds me of head gasket failure... check compression

 

[nkiserlexky]

same problem here

I had the same problem and I took my P5 to an auto zone and they hooked their lil computer up to my car and it said something about O2 sensor.
So it kept dieing on me at lights (scary thought when I have my 21 month old son in the backseat) and we took it in. They first changed the wheel bearings (my car was making a grinding noise) and then they changed plugs and the light still kept coming on. They took it back in again (meanwhile the loud screaching belt noise still continues) and they finally got the dieing fixed. I honestly cannot remember what they replaced but all together with bearings, plugs, and this new fix almost $600

 

[hoanmy]

I would try to the egr and sea foam stuff first. Sometimes problems aren't as serious as you think. Take some time and treat your p5 with some love...in the mean while pick a good location to set you car on fire and claim it as theft with the insurance. Cost=$2.67 for a gallon of gas and some free matches.(pow)