I recently started having trouble with my 2007 X-type 3.0 AWD. The car ran fine. Then I washed the engine. After that my car has run terrible. It misfires and skips. I assumed something was wet and let it sit in the sun for a few days to dry. The check engine light is on, and flashes when I am accelerating. My assumption was a coil got wet or something. I took it to my mechanic. He said there's a bunch of codes. He thinks I may have ruined the computer (or ecu/ecm, whatever it's called!). While I truly trust this mechanic, I'm just wondering if anyone else has run into this sort of this? Would washing the engine ruin the computer?

 

pdfisherman, odds are, if you are getting a bunch of misfire codes (P030X where X is the number of the cylinder that is misfiring) and/or a bad cat code, then odds are you have water inside your plug holes and you simply need to pull the coils off of the plug well and dry things out. This is not an uncommon thing based on what you did.

Start there and then see what you have. The coils are somewhat sealed. So, just letting it sit would take a lot of time to get it to clear itself. Having the engine up at temp will help, but still takes some time. If you are still having issues after the plug wells are dry, then you are looking at the computer.

 

Thanks Thermo. I'm getting codes for cylinder 1 and 3, ( of course the ones in the back!). I will look into it this weekend and see what I can find. I'm hoping its water in coils. I'll probably replace the plugs and coils while I have it off anyways. If there's no water I'll look into a computer. Is there anyway to test a computer or is it a matter of trial and error?

 

pdfisherman, the only way to test the computer is to hook it up to a factory machine. But, that is not something that most people have in their garage. So, odds are, if you get the computer tested, it would be at a dealership and they will probably charge you for an hour of labor which is going to set you back about $150 once all is said and done.

 

flashing MIL = misfires so bad they are cat-damaging

Usually bad coils so fix ASAP or you'll be changing a cat as well

 

Don't assume a computer fault.... the problem is more than likely something peripheral. Though computer faults and codes may be showing, these are likely to be symptomatic of something elsewhere.... a good mechanic and or auto electrician should be able to diagnose 'why' the faults are ocurring.

 

Thanks for all the help. It turns out there was water in the coils. I dried it and replaced the plugs and coils. Now it runs great. Thanks again!

 

They're supposed to be sealed so see where water's getting in / change gaskets / etc. Should be sealant (sorry can't recall what exactly) on the coils, too.