dwhogan81

Found myself in need of a second car with my wife finally finding a job after being unemployed for a time. So I shopped around, test drove a few at various pre-owned dealerships, and fell in love with one in particular. So as of 3/1 I became the proud owner of a 2002 Miata (my first).

After I got her home, I began poking around every nook and cranny. She's had her top replaced at somepoint (looks fairly new) but beyond that i can tell her last owner just didn't give her the love she needed. I have no service record to go by, but her oil was filthy(which i changed immediately), once red air filter was black (changed), and now a p0128 code has popped up (gonna check the thermostat first) and have no idea if/when her timing belt was done, and based off the other maintance slumps, her injectiors are likely filthy as well. Body is in great shape (minus the rock chip on her nose, and missing her font emblem), and she runs good, she just needed a proper home.







and here's the nasty air filter i pulled out of her poor thing.

sixshooter

Nice looking car. Welcome to here!

dwhogan81

Ok, so after contemplating the p0128 CEL dillema a bit, I was watching my car as it was at idle (for about 15-20 minutes) the fan started kicking on for 4-5 seconds, then turning off again. When the fan would kick on, the idle would jump up roughly 150-200 rpms, the fan kicks off, and drops back to normal. My mind is turning away from the thermostat, and leaning towards a sensor or possibly the fan(?). Some of you guys that have more wrench time on a miata than me may be able to at least point me in the right direction. (i really need to get a repair manual next payday.)

flying_solo

iTrader: (1)

That is a funny one. If it keeps cycling I too would assume it's not a stuck open thermostat as the fans kick on. The fans kick on via a thermal switch on the back for the NB1s, but I don't see how that would throw your code. I did see the following thread on miata.net:

CEL - P0128. Replaced thermostat, didn't fix it? - MX-5 Miata Forum

Check out the last comment related to an air leak on the intake, I think this makes sense:

dwhogan81

well now, that bit about the air intake is interesting, i'll look into that as well then. the thing that had me suspecting the fan was basing the fan operation off an OBDII code site, saying I should "Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary."

After re-reading my previous post, it occured to me i failed to clarify that the fan cycles on for a few seconds, then off for a few seconds, then back on a few, rinse and repeat. that to me didn't seem "normal."

Even with the interesting issues im encountering, I think i've found my 4-wheel soulmate, I don't think I'll ever be as happy driving anything that isn't a Miata. I hadn't driven a stick in about 7 years, so the first few weeks were a bit rough, but i've managed to get recoordinated with my feet finally.

dwhogan81

under the hood shots:

dwhogan81

No air leak that i could detect (even with soapy water all over the air intake) so I bit the bullet today and pulled the thermostat housing, since I had little else to go by. Inside, i found un-arguable evidence that I tend to over think problems. Not only was the thermostat stuck open, the valve had slid 45 degrees sidways at some point. Replaced it, reset the computer, and after even a cool night like tonight, she warmed up nicely, with none of the wierd idling/fan cycling issues. Will keep watching it to ensure its truely fixed (and for leaks around the new gasket, since i don't trust my mechanic work 100%) but the car feels like its running happier.

As for the above shots, I was surprised how clean everything is for being an 11ish year old car with almost 115k miles on it, but also wanted to use them for a before/after regarding any mods i end up doing. Before I begin, I deffinately have alot to learn about the car and what I'm doing (which buys me time to save the money to make said upgrades).

sixshooter

I'm glad you found the answer to your problem. That is a very clean engine compartment. I want to do nasty turbo related things to your VVT engine, lol.

I'll be doing a trackday at Roebling Road with NASA-SE on April 13-14. You should come out for a bit. Unfortunately, SE won't let me have passengers for ride-alongs but I'm sure we could get one of the veterans to give you a spirited session on the track if you were interested.

Redcap

Wish my paint and engine bay still looked like that, welcome to the board!

dwhogan81

Thanks , and Six, I've been thinking a turbo is just what she needs, but wondering if i shouldn't upgrade the suspension/chassis before boosting the hp, just to make sure the tires stay firmly attached to the asphalt. My brother is into drifting (was running a Honda s2k last i heard), I don't think I have the nerves for it. I am, however, very interested in seeing what NASA is all about, been checking out their site quite a bit the last few days.