Cold start engine shudder

[Prosymnus]

Hey.

I'm having a persistent problem with my '04 Mazda3 where after a cold start (car left off for 6-8 hours or so) it cranks a lot before starting then the engine will shudder badly and sometimes cut out. After that it's fine and the car works with no problem. No CEL or anything.

Have any of you encountered that problem? If so how did you get it resolved?
Thanks in advance.

 

[thedude82222]

I have a 05 mazda 3 with 70k miles. It shudders/shakes pretty bad sometimes when I'm stopped while in drive. It started a few months ago and happens off and on throughout the day. Very strange. I have been searching forums and it seems like a quite a few people have the same or similar issue. Some say it is the #3 motor mount, but as far as I can tell mine looks fine. If ANYONE has an idea or knows what the problem is please help. Thank you.

 

[hat1018]

Hey.

I'm having a persistent problem with my '04 Mazda3 where after a cold start (car left off for 6-8 hours or so) it cranks a lot before starting then the engine will shudder badly and sometimes cut out. After that it's fine and the car works with no problem. No CEL or anything.

Have any of you encountered that problem? If so how did you get it resolved?
Thanks in advance.

My best guess is a fuel delivery problem, like low pressure or clogged fuel filter. Just a guess but it's a start.

 

[Prosymnus]

I've been doing some research on engine oil. It seems that 5w-20 (recommended for the 04 Mazda3) gets around the engine faster.
On my last service the mechanic suggested 10w-30 so I suspect that the thicker grade may be responsible for the problem (it did start soon after the service). I'm trying to buy some of the 5w-20 to see if that solves the problem. Will post results.

 

[hat1018]

Yes 5w oil is recomende because of small oil passages to engine bearings.

 

[Prosymnus]

Changed to some 5w-30 oil almost a week ago and the problem persists. I've resorted to an online mazda expert to see what he'll suggest. He's recommended checking the plugs but I doubt that's it since the problem only happens on cold starts.
Also, there's no rough idle so not sure it'll be related to the EGR valve.

 

[Prosymnus]

My best guess is a fuel delivery problem, like low pressure or clogged fuel filter. Just a guess but it's a start.

I used an injector cleaner which is poured into the tank a while back and it didn't change anything. Will try it again since there's no harm in doing it. Also did an oil change so the filter was changed. Problem still persists...