How to best dry my engine after a coolant mishap?
May 31, 2011 12:05 AM Subscribe
What's the best way to dry my engine after a coolant mishap?
My 1998 Crown Victoria P71 has been misfiring since I flushed the cooling system on Saturday, and I'm pretty sure it's because I accidentally got the engine wet (there was a coolant spill followed by a series of extraordinarily clumsy garden hose maneuvers). The car still starts and runs, but it's rough when idling in drive, and the check engine light is on with intermittent episodes of blinking that last for about a minute and recur every 3-5 minutes, seemingly regardless of speed, acceleration, deceleration, etc. The codes coming back are PO305 and PO307 (suggesting that cylinders 5 and 7 are misfiring?). I live in Houston, and it has been very humid lately, so I'm not sure how well the engine would dry on its own, especially with the A/C generating condensation whenever I drive. The car has a coil on plug system. Do I need to take it apart to dry the components, or will it dry out on its own if I leave it parked it in the sun all week?
I don't know if this is important or not, but today I noticed that when the A/C is on max, the car misfires almost continuously, but when it is on the normal A/C setting, it smooths out and drives almost like normal. Does anybody know why this would happen?
Many thanks for any advice!
My 1998 Crown Victoria P71 has been misfiring since I flushed the cooling system on Saturday, and I'm pretty sure it's because I accidentally got the engine wet (there was a coolant spill followed by a series of extraordinarily clumsy garden hose maneuvers). The car still starts and runs, but it's rough when idling in drive, and the check engine light is on with intermittent episodes of blinking that last for about a minute and recur every 3-5 minutes, seemingly regardless of speed, acceleration, deceleration, etc. The codes coming back are PO305 and PO307 (suggesting that cylinders 5 and 7 are misfiring?). I live in Houston, and it has been very humid lately, so I'm not sure how well the engine would dry on its own, especially with the A/C generating condensation whenever I drive. The car has a coil on plug system. Do I need to take it apart to dry the components, or will it dry out on its own if I leave it parked it in the sun all week?
I don't know if this is important or not, but today I noticed that when the A/C is on max, the car misfires almost continuously, but when it is on the normal A/C setting, it smooths out and drives almost like normal. Does anybody know why this would happen?
Many thanks for any advice!
Do you have a compressor and a blower attachment? I'd follow maxwhelton's advice and, in addition, use the compressed air to blow off the area above the plugs rather than try to get at it with paper towels. I think the threading is snug enough to minimize any real danger of forcing liquid into the cylinders.
posted by phearlez at 6:09 AM on May 31, 2011 [1 favorite]
posted by phearlez at 6:09 AM on May 31, 2011 [1 favorite]
Beware that running your car in this state (with misfiring significant enough to make the check-engine light blink) will damage your catalytic converter, which is very expensive to replace. You should immediately stop running it.
I'd replace the coil packs on 5 and 7 and never look back. It's not worth messing with. If a garden hose spray caused this, EVEN if they start working again in a few more days, they'll later start giving you problems in rain and fog.
When in doubt, replace 13 year old ignition system parts.
posted by fritley at 9:53 AM on May 31, 2011 [1 favorite]
I'd replace the coil packs on 5 and 7 and never look back. It's not worth messing with. If a garden hose spray caused this, EVEN if they start working again in a few more days, they'll later start giving you problems in rain and fog.
When in doubt, replace 13 year old ignition system parts.
posted by fritley at 9:53 AM on May 31, 2011 [1 favorite]
Response by poster: Well, friends, when I got home from work tonight I pulled the coil packs and found the spark plug wells dry but somewhat dirty. I cleaned them as best I could with q-tips held by needle-nosed pliers (no compressed air available) and then sprayed them with WD-40. I put everything back in place, swapping the coil packs for cylinders 1 and 5 as maxwelton advised and then cleared the codes before taking it for a test drive on the beltway. The check engine light stayed off, even with the pedal to the metal and the A/C on max! :) Thank you guys for the advice!!!
posted by fernabelle at 8:46 PM on May 31, 2011
posted by fernabelle at 8:46 PM on May 31, 2011
This thread is closed to new comments.
Be sure to investigate the plug wells (if the plugs are down inside a "tube" in the rocker cover) and remove any water in there with paper towels. If there is standing water and it's been in there awhile, you want to make sure the plug ends and the snap part on the coil packs aren't corroded.
The engine will be under a greater load when the AC is on max, which will make any coil weakness show itself.
Do not remove the spark plugs themselves until the well they're in is dry.
if you remove the coil packs from the cylinders, be sure you keep the wires leading to each one organized, they should naturally fall to the right cylinder, but if there is any confusion, label them.
As long as there is no standing water, it should all dry out in normal driving, it's going to be very hot in there, 200 degrees or more. If you don't discover any standing water, you can test the coil packs by swapping #1 and #5, say, clearing the check engine codes, and see if the problem follows the coil pack.
(Coil packs are neat devices, but it's maddening to me I can buy a single coil for my old cars for $30 and I have to pay $150 each for the modern cars...more than $1000 to replace every one on a V8. Bah.)
posted by maxwelton at 2:30 AM on May 31, 2011