my miata is still acting up

[Nemesis]

well my car is fine and dandy except this on thing...i'ma post it as detailed as possible...

The car starts fine, but there is a SLIGHT knocking sound when i first start the car, but then it goes away after...let's say...3 minutes or so, maybe less. When the car first warms up she redlines easily without problems, but after a few minutes driving as the engine gets warmer, she begins to act up. If i'm on the highway and need to downshift, I'll do so but as soon as i get on the gas, the rev's begins to...well...more simply put "slip" or hit it's limit 2000 before the redline (or in other words, it acts as if it redlines at 4000RPM instead of 6200RPM). This only happens when the car is hot...the cooling system works fine, i checked for leaks and everything, spark plugs, spark plug wires, and fuel filter have all been changed to brand new...so i'm jus totally lost on what it could be.

and there is NO check engine light on either...

I really can't figure out what it is...

[Parry]

is it running rich/lean?

Coolant temp sensor maybe?

[kaitokid21]

i take it you tried miata.net? they have excellent faqs and forums.

the knocking is common to a lot of miatas mines does it once in a while..sorry i can't help you on your other problem

[Jeff Abbott]

Nemesis,
Def check Miata.net. I am a member there. I have a 99. That site has AWSOME knowledgeable people. Do a search there. You question may have already been answered...

[CRASHDRIVE]

Have you tried putting high octane fuel? It just might be a knocking from a low octane also, TPS, Revlimit. I'm not really familiar with Miatas, but those are the basics.

[Jeff Abbott]

Also, with a stock miata sh1tty 87 oct. gas still shouldnt cause a knock. There shouldnt be any uncalled for detonation.
As for the knock noise- top or bottom of engine?
If its the bottom, I would be worried. If its more of a tick noise from your valves- thats a bit more typical. Try a heavier oil. Like 10w30 or 40. If it continues you probably need your clearences checked on the valves.
Knock that would be typical should only be on forged pistons waiting to be warmed up to size.. I think
Each car is different but an engine is still and engine. Knock = not good
my .02

[Nemesis]

well i figured out the knock problem, it happens in alot of miatas actually. i found the answer on Miata.net and tis jus cause oil hasn't reached the lifters yet since the oil is still thick, i noticed this happened alot during cold weather...so that problem is solved...

the rev thing is still a mystery, they say it might be the cat, or the muffler has jus gone to crap, so i gotta go check this out tommorow...thanx for the help guys, this can be locked now

i'll post again if i still can't find the answer, or i'll jus kill myself

[parknglotdrfter]

hmm... when that happens on dirtbikes you usualy have something wrong with the piston/piston ring or your not getting enough spark... but you already checked that, i would disect the block but it's a little more difficult on a car.

[Parry]

Originally posted by parknglotdrfter

hmm... when that happens on dirtbikes you usualy have something wrong with the piston/piston ring or your not getting enough spark... but you already checked that, i would disect the block but it's a little more difficult on a car.

Yea...uhh...stick to dirtbikes for now.

Without any other information it's sorta hard to tell you much. You need to be specific about how the car is running in general other than it's running out of steam way before redline.

How is your gas milage?

[Nemesis]

its pretty good

err 250? 300 mpg

i'm open to questions if it helps you guys. i'ma ognn be guttin the cat and i hope that fixes the problem

[Fresh_Prince]

Originally posted by Nemesis
its pretty good

err 250? 300 mpg

i'm open to questions if it helps you guys. i'ma ognn be guttin the cat and i hope that fixes the problem

HOLY SH*T, I WANT A MIATA NOW!

[Jeff Abbott]

Nemesis
Good to hear miata.net helped you. Its a great resource. I apologize i wasnt more clear on the knock in the top. This is basically what I meant. The lifter noise. Try a lighter starting viscocity oil in the cold weather. maybe 5w30 not 10w30. It will get those lifters quicker..
Also did you remove the cat? I was thinking that sounds like a real possibilty. I'm surprised an o2 didnt throw a CEL light though, if it was clogged. What year is your car? If its a 99 or newer it would have 2 o2 sending units and the second one should pick up on that. Anyway, make a post on miata.net and I am sure someone will help you. Call flyinmiata.They would give great suggestions too.
Keep us posted. As a fellow miata owner I am down to know whats up..

[Nemesis]

Originally posted by Fresh_Prince
HOLY SH*T, I WANT A MIATA NOW!

haha i meant 300 miles per full tank...haha...its more like 23? mpg...something like that, you do the math, its only like a 10g tank...i think less

and thanx turns101, i'm gonna be gutting the cat today to see how that works, if it continues to act up, i'll call flying miata or post again on miata.net...

i'll post here as well to keep you guys updated

[Nemesis]

so i decided to gut my cat, as it supposebly was the problem with my car. So i go underneathe and do the usual, let it cool off, spray it with rust eater or liquid wrench and gie it sometime and start a tearin apart...o boy did i tear it apart...one of the bolts that held the freakin catalytic converter busted on me so i got a MINOR exhaust leak, but it annoyed me none the less...but it was ok, i was gonna fix my rev problem and all was going to be good, w/ or w/o cat...we take a break and fart around a bit and i start my car w/o the cat on...o man that stuff was LOUD! Like, make your ear drums bleed loud, so i say to hell with it, lets get a workin on guttin and ge tit over with...we remove the entire cat and guess what!!! NOTHING!!!! The thing was empty, so now i've narrowed the problem down to "WHO THE HELL KNOWS!" cause i'm given up at this point...i'm leanin towards tranny which i really don't want it to be...but, we'll see how it goes, not gonna mess with her until Dec 5th though...

[Jeff Abbott]

Nemesis:
What year is your car??