I just bought back my old Focus—my first manual car—for $300. I couldn’t pass it up, even though it needs a lot of work before winter. The water pump gasket is blown and leaking coolant, so I’ve been using water in the cooling system for now to keep it from running dry.
Here’s the issue: I was in the middle of replacing the brake master cylinder, so the airbox was out, the MAF was disconnected, and the fuse box was moved. I put everything back quickly to start it up after it sat for a week, and now it idles like garbage. I completely forgot I had water in the cooling system, and it’s just about freezing outside.
I’m throwing codes P1451 and P0113. Did I mess up by leaving water in the cooling system, or is it something else?
If it’s not below freezing, it’s unlikely to be frozen. Did you tighten the accordion tube when reattaching the MAF? Air leaks can cause a lot of idle issues. Also, did you make sure all the sensors and the air intake are properly connected? I’ve run just water in the cooling system for a couple of weeks before without issues, but you’ll definitely need to flush and add coolant soon.
Recheck everything you reinstalled. That vent valve code (P1451) could be the issue—it’s often related to a vacuum leak. I’d guess you might have missed reconnecting the EVAP purge line, which would explain the bad idle.
@Vern
Checked everything—aside from the brakes, everything is hooked back up. The idle calmed down from almost stalling and revving itself to sounding like it has an aggressive cam installed. Now it’s just throwing the P1451 code.
Blane said: @Blane
Wait… would that cause the idle issues? How are brakes even related to the engine idle?
The brake booster uses vacuum from the engine to function. If that line is disconnected and not plugged, it creates a vacuum leak, which messes with the idle.
Vale said:
Please tell me you drained and refilled the cooling system. If it freezes, you’ll crack the engine block. Don’t let that happen.
Started the car, and smoke went everywhere—the driveway was a cloud of white. By the time I remembered to drain the water, it was too late. The water pump already had a bad leak, and now I might have a cracked block or a freeze plug issue.
I’m not too upset, though. This car means a lot to me as my first manual, and I plan to rebuild it over the summer. Hoping for the best!
Atlas said: @Blane
On a Focus? Not worth it—they have too many problems, especially with transmissions.
You’d be surprised. I learned to drive stick on this car and must’ve money-shifted it daily when I was younger. Sold it to a kid who didn’t know how to drive, bought it back, and it still shifts great.
