03 discovery, went to the car wash today after reparing a small coolant leak (throttle body heater plate) to wash off my engine. After I was done, I drove off and the check engine light came on. Noticed a very small rough idle and hesitation when I gave it gas, but it is not a continual hesitation or rough idle. Any thoughts on what might be causing that light to come on. I have brand new Magnacore 8mm, new spark plugs ect. Could it be just moisture ?

GODSDOZER

 

Start with free stuff first. Check and make sure your plug wires are seated tightly at the plugs and at the coil.

 

You most likely still have your old factory plug wires, which are going bad and short to the engine when they got wet.
Probably time to install some new 8 mm Magnacor wires.

 

I know what you mean Dozer. Ever since I installed my 8mm Magnecores, I can't even MIST my engine without SES light and 'catalyst damaging misfire' codes! Very frustrating.

 

I took it to my mechanic today to get the codes read. Here is what I found.

1. P0305- cylinder 5 misfire

2, P0132- o2 sensor circuit high voltage (bank 1 sensor 1) front sensor LH bank short circuit to battery supply.

3. P03303- cylinder 3 misfire detected

4. P0305- cylinder 5 misfire detected

5. P1300- Random/muliple cylinder misfire detected.

Why would washing the engine make these codes come on?

My mechanic cleared the codes, I drove the truck around for about an hour and then the SERVICE ENGINE SOON/SPEND ALOT MONEY light came on again.


Any recommendations?

thanks

 

coil pack

 

Can you tell me how or why its the coil pack? does this happen everytime i want to wash my engine at a car wash? Thanks

 

This happens because water is getting where is should not be and shorting out your spark.
So, first you need to check and make sure that your plug wires are seated correctly.
Then look for cracked spark plugs, the porcelain can be cracked from the factory, not common but it does happen.
Next would be the coil pack.
It gets wet and shorts out.
if your plug wires are not seated correctly water will get in between the plug/coil and plug wire and short it out.
As we all learned in elementary school water is a excellent conductor of electricity.

 

Back to my original question, do you have factory wires and what is the mileage on your engine.

Bear catfan,
I have run those wires for over 7 years, never had a misfire had the engine deep enough doing water crossings to get the wire wet and power scrub the engine after every trail or at least one a month to keep it clean, never a water miss.
You may want to look at you coil connections to make sure they are not loose.

 

He has already replaced his plug wires Mike.