Spuddering Bad at Stops
 

Hello,

I have a Mazda 6 2005 S 3.0L automatic with 95k on it. I'm a girl trying to learn what's going on and save $$$.

About 2 weeks ago my car started spuddering (bigger than vibrations but not bucking, no noise) at stops; almost like it's going to stall. It happens when in Park or stepping on the breaks. It also happens in Neutral. I have noticed that when I first drive it around after it has been parked for awhile the symptom is not as bad. The 'warmer' or longer I drive it, it gets worse. Let me clarify: my car is not hot or over heating.

Me and a friend changed the spark plugs even though they looked good. We replaced the pcv as well and it didn't seem in poor shape either. The filters look good. Oil has been changed. Battery is well.

My mechanic said it might be a bad engine. And, that it's a Mazda thing. He says if that's the case (and I happen to need all new struts as well-never been changed >.< I know) I might just want to think about a new car :eek:

I welcome any constructive ideas, suggestions or advise.

Thank you much!!!

Here we go again.
Basic stuff to do:
Clean EGR Valve
Clean MAF Sensor
Clean Throttle Body: Rough Idling Issues | MotorWeek

If the above don't help, change all ignition coils as you have lots of mileage.

Thanks for helping out! This is my first time ever learning and fixing a car. This gal is never to old to get her hands dirty ;)

**********7 with dirty hands:
Welcome to the forum and a thumbs up for your kind of finger nail job!

You replaced the spark plugs, did you also replace the wires?
Your mechanic says it is a bad engine? He is your Ex-mechanic right now. All your car needs is a basic tune up, what 'noggin' said.

Is the check engine light on? If so get the codes read at the parts store and report them here.

You can learn a lot of stuff by watching Youtube videos:
EricTheCarGuy
ScottyKilmer
Richpin
briansmobile
realfixesrealfast

This car has cop's (coil over plugs) most common problems are bad coils. Mazda doesn't have a big issue with bad motors unless u severely neglect the car. If u have the old spark plugs look for black arch marks on the sides of them. Also pull out the coils and pull the rubber boots off of them and look for rust where the spring portion goes into the coil. Alot of the time u will find rust and green corrosion in there. The throttle body is another culprit that could cause the problem. The earlier 3.0 engine also had a problem with buildup of carbon in the intake ports and would cause sputtering and staking when the vehicle warmes up this us called fuel soak its when the carbon builds up and the fuel being injected hits the carbon and the carbon just soaks it up making it so the engine is not getting the amount if fuel that it needs to fire correctly. To check this (easiest with a scope) u need to remove the upper intake manifold which is pretty simple and look down the lower manifold to the valves and see how much carbon is sitting there. Clean it out with a wire brush and cleaner( brake or carb cleaner)

Thanks Tan! I haven't officially given the mechanic a boot. My friend that helped me is about 2 hrs away and I just don't have the experience, confidence and tools to tinker and fix on my own.

I did not change the wires... I read prior, else where, I didn't need to for my car. Sounds like I read bad info. I'm not even convinced I needed to change the nice platinum sparks plugs, but I did >.<

The check engine light came on but turned off after I check my air filter. I think the wiring around the filter 'container' was loose. I'm sure I've driven it 25 miles since too.

I didn't know an auto parts store would/could read my car. I'm assuming they charge... it's diagnostic, correct?

Thanks for the head up on some specifics for YouTube. That's exactly where I found a step by step instruction to remove the manifold =) That brings up another point. My friend ended up forces a screw into the manifold =/ I think the barrel was striped... I hope to god we/I can remove it.

Racer, thank for all your info. I'll have to re read this again and do a bit of self education to understand better. You all are giving me hope :) Happy New Year and I'll be back for sure with updates... if you all can help more later.

I have to add this, but it may not be your problem, but you should be aware of this:
my car had an internal brake booster leak. It would run rough @ idle and check engine light (cel) would come on occasionally. Once in a blue moon i had no power brakes! We finally figured it out on a computer scanner in the shop when we pinched off the vaccuum line going to the brake booster which is near back of intake plenum. I had the booster changed from 1 @ Junkyard, and all is good now.
The whole process took about 6 months as it did not happen all the time.

Hi **********7
I'll put my comments in , uhmmm, tan.

That's part of the learning curve. Novices to mechanics tend to overtighten bolts, nuts and srews, in particular the small ones. They also tend to use the wrong tools for a lot of fasteners. There are ways to get a bolt out of a stripped threaded hole. And there are ways to repair threads. We cross that bridge when we get there.

Happy new year!

Two things:
1.The dealership guys said me and my friend did a good job doing what we did :)
2. It was 2 bad coils #1 and #3. I just had al 3 under the manifold replaced by them. I was done with that manifold lol.

Thanks again all for your suggestions and help. I plan to stick around and learn about my car when I can!