Hi everyone,
So I go to wash my car today at a diy high pressure washer. As soon as I start the car up after the wash, I get a very rough idle, with rpms fluctuating, and the check engine light comes on. I immediately stopped the car and checked around the engine bay, but everything looked alright. I started it up again and this time the engine rpm was constant, but the sound was off. The check engine light flickered on and off a few times, then stayed on. I decided to drive the 2 minutes back to my garage. At all rpms above idle, the engine sounded and responded fine.

So I have to ask the dreaded question... do you guys think this is IMS, or something else? I changed my oil a few months ago before a track day and cut open the old oil filter. There was no trace of metal shards, and the engine has been performing fine.

I'm wondering if maybe some water got inside the ecu. I don't understand how else a car wash could cause something like this.

 

Sounds like the plugs/ignition wires/ and or the coil packs got wet. If you have access to and OBD reader, that may help diagnostically

 

Thanks AJ. Unfortunately I don't have an obd reader and my local tech is closed on weekends. If it is any of the parts you mentioned, this something that'll correct itself after the car dries?

 

Did you wash the engine? Get it wet?

Also, check that the car drains are ok and no water accumulated from a blocked drain and put water in the cabin or a seal around the rear trunk allowed some water to get into the rear trunk. The car's DME is located against the front wall of the rear trunk. Check all carpets in the cabin and trunks for any signs of dampness.

My guess is that if you find no signs of any moisture/wetness the car washing got some water on the engine probably the coils and the engine behavior was the result.

As long as the engine is not making scary noises or producing any other scary symptoms that suggest a more serious (and internal) engine problem letting the engine idle and get hot will drive the water out of wherever it got into.

Sincerely,

Macster.

 

go to Advance Auto or Auto Zone, they will check it with their OBD meter. My guess there is nothing wrong. If no major problem the parts store will not delete the code but you are allowed can if you ask.

 

Hi guys,
Thanks for the replies. I let the car idle for 10 minutes, and the engine sounded fine. I unplugged & reconnected the battery and the check engine light has not come on since then. As everyone's said, it looks like something was wet. Of course, as soon as I saw that check engine light I instantly thought ims

I'm just surprised in my years of ownership that this is the first time I've had this problem after a wash.

 

Man, I hope nothing is wrong. I would have it checked out if you are not able to do it yourself get it to your mechanic. I am still waiting to get my engine back. The engine ships out to CA this week. Mine had no indication what so ever and then I lost power and smoke was shooting out the back. Mine was a blown gasket. It is costing me a lot to get it fixed. Before this happened to me I may have given you different advice. I am not trying to scare you, it is probably nothing but your down side could be huge if it is something. I would play it safe.
I hope it is just a little moisture issue.

 

As mentioned, sounds like your coil pack(s) may have gotten wet. Hope that's it instead of the IMS. No doubt a code reader will tell you specifically.

 

its like everything else.... if it's wet, she runs a little rough.

till she's dry again.

 

running rough is not the same as "sounds like marbles in a coffee can"

esp after a was with power hose - you may want to inspect your coil packs


(and change your IMS so you can stop "wondering" if every noise is the dreaded tick tick boom)

 

Yeah... I'm waiting for the clutch to go to do the ims. You'd think with all the autocross flogging, the clutch would be dead by now but it seems just fine!

 

LOL - a good flogging doesnt eat much clutch !

 

+1000000000000

BTW, My ignition switch is acting up again. I changed the electric switch only(not the whole mechanical mechanism) about 1-2 years ago. Do you think it may be my IMS?

 

These things happen when you wash... Check out this thread: https://rennlist.com/forums/996-foru...otten-wet.html