washed the motor the other night, started it and it was misfiring. No CEL, no misfire codes, getting weird codes, like maf, iac those sort of things but nothing will stick. any ideas!!

 

Howdy! I know the exact problem you're talking about. I cleaned the engine of my 99 Mustang GT at a carwash once, and afterwards, it ran pretty crappy. I could definitely tell a cylinder was misfiring (a few weeks before, coil plug went bad, so I was familiar with the engine running on less than 8 cylinders). I'm assuming some moisture got down into the little pockets where the spark plugs are. Anyway, I took out all the coil plugs and disassembled them. All you really can do is take the rubber boot off the coil plug. Then I cleaned them off with a rag, and blew compressed air all over it to get any moisture off. Then I used the compressed air to blow out the pockets (where the spark plugs are). Finally, I applied dielectric grease to the insides of the coil plugs and put them back in. Total time is about 20-30 minutes. At first after I did this, it still ran a little sluggish, but after about a hour or two of driving, I guess the heat from the engine really dried up whatever moisture was causing a problem. But that's all assuming that moisture was the problem. But after that, it ran like a beast again. Hope this helps!

 

these have the cop's. it happened like right after i sprayed down the motor. wouldnt it throw the cel light due to not firing or seeing a rich mixture by the o2 sensor?

 

water + engine = bad
you shouldnt be useing a hose or be putting too much water on your engine. use a rag next time with a little water on it. the misfiring is probly the spark plugs being a little wet like cpaggie_07 said.

 

I did the same thing on my older f150. Just take the coils/plugs off and dry it out. I put some grease on mine and it never did it again. I thought they fixed that though, my newer trucks dont do that.

 

Exactly the same thing that happened to my (recently departed) 2001 with the 4.6. It will kick a code shortly - trust me. For whatever reason, some folks pressure wash their engines and never (in the short term) have any problems. Some of us gently rinse ours off and end up with water down the plugs and all sorts of problems. My learning? Never "wash" my engine again.

To solve your problem, you've got to dry things out. When it finally does kick a code, you can zero in your drying efforts to a particular cylinder or more like others have said. Dielectric grease is a good item to add on re-assembly too. Good luck!

 

WD40 = "water dispersal formula 40". spray it where you suspect water infiltration. it will drive the moisture out and cure moisture related problems. Careful around hot engines though as it will burn.

 

When I had that problem with my Mustang, I was told (on mustangworld.com, where I post regularly) that the best way to clean your engine is to have it professionally steam cleaned. Although it costs more than using a carwash, it really does a good job, and you'll have almost no problems. My next engine cleaning for the truck will be a professional task.

 

Where can you get a proffesional steam cleaning done at?

 

I'm not sure, as I've never had it done, but I'm sure if you talked to anyone at a performance shop, body/paint shop, or hell, even a carwash, I'm sure they could point you in the right direction. As a last resort, I suppose you could look it up in the phone book.

 

I have seen people still get misfires with steamcleaning, in fact it seems to be worse because its easier for the steam particles to get in between the cop boots and the plug well.

In any case, my stand on this is that you need to remove your COPs, and spray the plug wells out with compressed air and let them dry out. Also make sure the COPs are good and dry. This would be a good time to put some di-electric grease around there to prevent this from happening again.

Also, if you decide to wash your engine again, just be sure to keep the water away from the spark plugs.

 

ok took it to the shop yesterday and here are the codes they pulled...p1124 TP sensor, p1101 MAF sensor out of range, and p0505 idle air control. They are saying that the computer was reading erattic and possibly I will need a new computer. Any ideas of what i should do from here?

 

ITS FIXED, last night i got into it and replaced the plugs with oem and replaced the boots. after pulling the #2 cylinder boot, i noticed that the boot was split at the bootom and throwin the spark to the wall and not the plug. Hence no CEL light and no misfire code. Thanks to all for the help, couldnt have done it without you and saved me over $300 in labor. If i ever find out who designed that plug configuration, I swear to god, im going to choke the ever living S#*T outta them!

 

Awesome! Don't ya love that relief after you fix something yourself instead of paying someone else do to it?

 

most of this sounds just like what is happening to my 5.4 now. I gave it a major wash last night and let me tell you.....#2...#5...and # 8 are all reading misfire codes. As well, the two up-stream O2 sensors are reading (fault). Tomorrow I will follow instructions and dry plug caps ect... As for the sensors? any recomendations? I have also been concerned with temperature when pulling. I have completly cleaned the rad...(frikkin watter) and am going to change tranny oil as well as have coolant changed. I will look into a larger transmission rad...any ideas on this?