I have a 2003 6s (no mods). I had a problem early on with engine RMP's surging and dropping during a cold start. RPM's would shoot to 2K, drop below 750 and almost stall, then shoot up to between 1500-2K. The engine would then idle normaly and settle down to 1100. Turns out there was a tech bulletin that prescribed a PCM update (i think - been a few years). I had mine fixed in '05. Still have her. 120K and except for the oil pan gasket that need to be replaced, she run like a top.

By the way, I think you can see your timing chain by taking off the oil filler cap and looking into the hole. You will see the top arc of the chain left of center of the hole.

 

hello, i took my mazda 3 to the dealer as it wasnt starting. they told me i would need a new timing belt, but are not sure it that is the case, they would need to take the engine apart and see what the real issue is. has anyone had this problem? and would anyone know the price range on a new mazda engine?

 

I have 2 things to say about that:
1) Find a new Mazda dealer or mechanic. And
2) That would be a pretty good trick since both engines that come in the 3 have timing chains, not belts... which is why my first suggestion. If they don't even know, I would be afraid to have them touch my car let alone rip the engine apart.
The timing chain is supposed to last the life of the engine, which short of an oil/lubrication catastrophe, should be well north of 100k miles.

 

i have desided to take it to a personal mechanic. he will look in to the problem. From what the dealer said i guess the chain might of have shifted and they wouldnt know until they took it apart. i am definetily lost for words:conf used:

 

Hmmmm.... I am confused by your "lost for words" comment?
The only way the chain might shift, short of stretching which as previously stated shouldn't happen for 100k+, is that a hydraulic (oil pressure based) tensioner has gone south. In which case I would have to ask why?
Are you the original owner or did you buy the car used?
Did something happen, like running it low on oil @ some point in its life?
Its also possible that you got a defective tensioner. Sometimes that happens, but its a one-in-a-million chance happening.

 

no, i am not the original owner. i lost the original keys in which i had to leave the car turn off for two months until i got the money to get new ones. once i did. i called a mechanic and he apparently made the key and had it programmed. but never started. i took it to the dealer and they made new keys and from there it never started. the had was well maintained. so i am not sure what the previous owner did?

 

It sounds like not a timing chain problem, but an electronic one caused by keys that are not correct for the vehicle. If the wrong key is inserted into the ignition it will be deactivated for 15mins. If the same incorrect key is inserted again it will be deactivated for 15mins again, and so on.
This is only a guess of course, but it sounds like the new key(s) were encoded incorrectly.

 

they have a recall on i have one same probs

 

hilton, Do you mean a Technical Service Bulletin? I am not aware of any recalls here in the States. And if so, for what? The timing chain? PCM reflash?
Sorry, but your post has left me confused. Please explain further.