Thursday, December 18, 2014

December Miata Maintenance

Before the last autocross I was down at Panic Motorsports to pick up a few things for the 99 Miata when one of the guys noticed a hose connected to the wrong port on the intake manifold. They did a quick swap back to normal and off I went.
Time to target that intake manifold.  For the non-car folks, that's the big silver bit with 4 metal tubes on it.
Days later we ran the final autocross of the season and on the way home the check engine light came on.  Knowing we just monkeyed around with engine hoses, I wasn't too surprised.  Checking the code, it showed an issue with the EGR (exhaust gas return), which is exactly what I expected.  After some research online, I found out the vacuum hose re-route that had been done to my car was a known quick-fix to stop the code from showing especially done in states where they need to pass emission inspection (like North Carolina).
After pulling the throttle body off, looking into the manifold from the front of the car.
The quick fix wasn't hurting anything, but it did indicate there was a build-up of gunk somewhere in the intake manifold preventing the correct flow of exhaust gasses back into the engine to allow the emissions control devices to work properly.  Time to clean it and resolve the issue instead of bypass it.
Now pulling the top half off.  It's tough to tell, but the severely clogged port is in the lower right corner.
Pull the intake off of the throttle body, remove the upper half of the intake manifold and there ya go.  There's little channels for the air or exhaust gas to flow that get clogged up with caked on gunk, as if it had been eating a steady diet of Big Macs for the last 16 years and it was time to scrape clean some arteries.
A somewhat less-blurry shot down into the lower intake manifold.
A good amount of dirt came out and the pieces were sprayed with cleaner and all put back together.  The check engine light was turned off and the car ran smoothly around the neighborhood.  I'll drive it a bit more this weekend to double check the light is staying off, but so far so good.  Added bonus, the car is about 5 grams lighter too.  Zoom zoom.

And that's just the pile of dried stuff that was scraped out.

I'll be hanging out at the Columbia Cars and Coffee this Saturday with some of the other SCCA and Columbia Miata Club folks.  Head out to the Village at Sandhills shopping center on 12/20 between about 8am  to noon near the Cracker Barrel area.

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