Its all due to the cold weather...its around 35 degrees here in arkansas...During the warm up process, about the time it drops to about 1200 rpms, it starts to knock just alittle bit untill it is completely warmed up after a short drive...or after I rev it up to blow the excess gas out.

I mean, all a knock is, is pre-ignition correct? The the knock sensor retards your timing making it run lean so there will be less pre-ignition...

As along as the knock isnt doing any damage, I think It should be fine right? The 8s run so rich I dont have to worry too much about it detinating...

I needs some answers and ideas of whats going on and what I have to worry about =]

 

There shouldn't be any knock. It was 30F this morning (coldest in a very long time for San Antonio) and my car did not knock at all.

 

is 8F in colorado springs and i dont get any knock

 

What weight oil are you using?

 

new sparkplugs time? (how many miles on your current set)

 

naw, plugs are brand new..maybe 3k miles on the set. RB ignition wires...I run 5w30 weight.

The knock isnt bad though. You can't hear it or feel it from the engine bay, you can just kinda feel it in the peddles from the the vibration and a slight thump sound...whos knows might just be the exhaust poping oddly in the mornings...because I do run 93 octane...might just be burning alittle slow...1200 rpms might be the lowest rpm that dumps the most fuel in the motor.

it only does it every once in awhile around that rpm....like....thump, thump......thump thump thump.....then it stops.......thump thump.............thump.......idk.

you can barly feel it or hear it...but this is the first winter for me with the car. 85k miles...runs perfect after it warms up...runs perfect on a cold start....its just during the cold start at around the rpm its doing it when its realy cold.

 

I have The same symptoms. I mean I hear little poping when the car is warmed up on the idle( about 750RPM) this is normal? the coils and plugs are brand new.

 

well mine dosnt do it at idle, just when its coming down from the cold start...suppose to idle at 810 rpms (with a manual)

Oh yeah, and why does it idle higher with the clutch in? I always take it out of gear when I start the car...when you let off the clutch at anytime, the rpms drop some. Does it just rasie them to help sync the gear in?

 

Sounds to me like nothing to be concerned about .
When you release the clutch the engine has a few extra components to spin around - that is why the drop in rpm.

 

awww, makes sense.

And yeah, I didnt think it was a big deal. Thanx guys.

 

hey where r u at in arkansas.. i just moved around that way

 

hey man hks is from Texarkana.....Sheehan is from yellville....me(pup) i am from Cabot.....where are you located at

 

I live in El Dorado. Only blue 8 for aways =]

 

Octane probably (predetonation). Try one octane level up.

No tappets/lifters in a rotary.

 

Is that the detonation you get before you get detonation ?

 

My own $.02;

Probably a bit of a front main bearing knock, depending on the mileage of the engine. Not necessarily a huge concern if you are not going F/I soon but I would switch to a 0W30 or 5W20 oil for the colder months.

What is the overall mileage on the engine?

 

You obviously knew what I meant so the glib response is pretty unnecessary.

I got my detonation and pre-ignition terms mangled.

 

No offense meant - it just sounded funny to me

 

Funny how? Funny like a clown?

Do I amuse you?

 

LOL I love that segment.

To the OP: In cold weather (and yours really isn't very cold) there's a greater incidence of condensation in the gas tank and therefore some potential 'hiccups' due to the water. Many folks go with higher octane gas, and keeping the tank more regularly full, in the winter as it tends to 'dry out' the gas. But you shouldn't be getting any pre-ignition (aka ping, knock) provided you're using the Mazda-recommended octane rating. Perhaps you're mistaking water in the gas for knock?

QUOTE=RotoRocket;3342124]Funny how? Funny like a clown?

Do I amuse you?


[/QUOTE]

 

Btw, ive been doing some thinking...and looking through the trobble shoot manual...and what ive come up with is...

I dont think the fuel filter has ever been changed, I got the car at 79k miles...well taken care of...but not that well as far as things of that nature go.

Fully opening up the exhaust after 80k miles changed the way the car acted ofcourse, doing this will make the fuel curve change due to the o2 sensors...

Now because of that, its going to put more duty on the fuel system...So, i'm thinking either the fuel filter is slowly getting more and more cloged up, ( which it has slowly been running alittle more rough over time ) or, the fuel pump relay go stuck closed...I'm going to check my fuel pump relay out after I get off work today...

If the relay checks out, im going to order a fuel filter and see if it stops the knocking.

Because we all know, the only way you can get a knock with a rotary is due to fuel issues...A hot spot is what you would call it, combusting a/f mixture at the wrong time...it might be missing the exhaust and burning right after making it knock...idk, all i know is its preignition...and thats not cool lol.

 

How do you know that ?

cold weather , cold motor , not under load . These are not conditions in which pre-ignition would occur .

 

Well what I mean by pre ignition is its being ignited by somthing other than the spark plug.

And its starting to sputter for a split second after running it hard down a long strip now...I wonder if the FPR isnt putting out the right pressure now...which its integrated into the fuel pump..soooo...idk, it could be a number of things...it sux, it realy does..

...havnt even driven the car 5k miles yet and its starting to **** up on me...3 oil changes with Royal Purple in 5k miles...and many other good things for it...even today going back to work...cranked it up, the power steering light come on...the steering was completely out on it...had to recrank the car for it to come back on...

I needa sell it quick...

 

You purchased a high mileage car *Just shy of 100k* and when a couple of extremely small problems arise, you're wanting to run out and sell her?

 

^ really... Cyber made an excellent point.