Coolant hose located at top back side of the engine split in my 2001 caravan, and dumped antifreeze all over. Hose fixed, but now engine drives and idles rough. Roughness smooths out at 35 mph + and returns at slower speed, or stop. Mechanic told me that there's a good chance that "something" is wet, that shouldn't be, and to wait until engine drys out. It's been two weeks, and still having same problem. I am thinking at starting with the plugs, and wires. The back 3 plugs/wires got really soaked. Anyone have a better place to start, or other places to check?

 

Fluid intrusion into connectors or plug wires can take a long time to dry out because there’s no air flow through the connectors. Even when it does dry on its own, it leaves behind corrosion.

I recommend checking for codes (they can be stored even w/out a check engine light) but there’s some connections you can check and clean.

While checking/cleaning the connections below, disconnect the negative battery cable to prevent accidental damage to the PCM.

Pull the plug wires at the plugs and the coil. While the wires are off, check for signs of tracking on the plugs (will appear as a black streak on the porcelain section of the plug). Spray with brake clean or electronic contact cleaner and blow dry with compressed air (a can of keyboard duster works in lieu of a compressor).

Do the same for the 4 way connector from the engine harness in the side of the coil. There’s also 2 large connectors on the opposite side of the manifold by the air intake - they’re known for corrosion issues - separate and clean as well, even if they didn’t get wet.

Any corrosion found will have to be cleaned or the connector/terminals replaced.

Apply a THIN FILM of dielectric grease to the plugs, wires, and connectors before re-connecting.

Reconnect the battery and attempt to start. If it’s still running rough, see if any codes have been triggered.