Two days ago while doing a routine oil change I noticed my kids engine compartment was real dirty as we had alot of flooding from rain a few weeks ago. I sprayed the engine with a water hose w/nozzle to clean it. DOH!, at the time I didn’t know any better. The car was driven without any issue briefly that day. The following morning the car was driven a distance of 25 miles without incident.
After resting 30 minutes the car was started and began to idle rough and stalled repeatedly. When I showed up to inspect the issue it had been sitting about an hour. I went for a test drive and the car ran good. About 20 minutes later iI get another call saying the car is doing it again. It was sputtering/ hesitating when I attempted to accelerate it began to stall unless I limped it along staying off the gas.
Once I got it home I started doing some research and discovered that my spraying water in the engine compartment was probably what caused the issues I was experiencing. So I began to go through the motions trying to repair. I also noticed the car ran good when cold but at operating temp it would run rough. The check engine light has not come on.
I replaced the spark plugs, plug wires, distributor cap & rotor, ect sensor, and air filter, I cleaned the throttle body port and IAC valve port with sea foam cleaner. I cleaned and tested the EGR valve & ports. Nothing has improved from my efforts.
I must of screwed something up good, since its been 2 days, it should be dry by now. I also been thinking that maybe some water got to the injectors. NOt sure if a cause, but the oil was changed right before I sprayed engine.
My course of action as of right now is.
1.Check and clean all electrical connectors
2.Replace distributor with a re-manufactured one $150ish ugh
3.Replace upstream o2 sensor $50ish
I sincerely appreciate any advice. Thank you in advance.
Did you squirt it down with a pressure washer? You need to check all the electrical connections for water. I would have guessed the plug wires or distributor. Was there any water on the plugs or wires when you removed them? Did you use dialectric grease on the boots of the plug wires? I would remove the cap and wires and let it sit in the sun for the day with the hood up. If you have garage and no sun put a fan blowing on the engine for a day.
I sprayed it with a regular water hose w/nozzle. I did not notice any water in cap, plugs, or wires. I did go over all these parts with wd-40 and compressed air prior to replacement. I replaced all said parts and did not use dialectric grease on the plug wires. Its been 3 days now since washing. I’m thinking since it runs good when cold and then bad when warm that maybe this will help narrow down the issue.
There are a few other items that need to be checked.
Since the precat oxygen sensor and the postcat oxygen sensor are on the front of the engine fairly out in the open, you could have gotten water into the connectors or into the vent holes of the sensors. I have not heard of any ill effects of water on the O2 sensors but you may have washed some oil or dirt into that area. Does the engine pull well at Wide Open Throttle, i.e. out of closed loop? Pull the connectorions apart; swab them dry; and lube with WD40.
The other items are the MAP sensor and the IAT sensor. The MAP sensor is high on the fire wall and the IAT sensor is by the air box so water may not have reached them. Again, service their connections.
Researcher 10:49AM There are a few other items that need to be checked. Since the precat oxygen sensor and the postcat oxygen sensor are on the front of the engine fairly out in the open, you could have gotten water into the connectors or into the vent holes of the sensors. I have not heard of any ill effects of water on the O2 sensors but you may have washed some oil or dirt into that area. Does the engine pull well at Wide Open Throttle, i.e. out of closed loop? Pull the connectorions apart; swab them dry; and lube with WD40.The other items are the MAP sensor and the IAT sensor. The MAP sensor is high on the fire wall and the IAT sensor is by the air box so water may not have reached them. Again, service their connections.
It runs great at open throttle from a cold start. After it is warm it will idle rough and if I put it in reverse it will stall if not given gas. Upon acceleration there is a “bog, loss of power, sputter” and it sometimes will stall but starts back up. I will check and clean MAP and IAT connectors.
knfenimore 11:03AM Sounds like the temp sensor maybe telling it that the engine is cold and it is making it run rich. Check that to make sure it is connected and dry.
I replaced the Engine Coolant Temperature sensor if that’s what you are referring too.
Today,I disconnected every electrical connection I could find in the engine compartment and cleaned with contact cleaner. I replaced the upstream o2 sensor. There is no improvement. I’m waiting for my re-manufactured distributor to arrive at my local part store.
Current course of action
Replace distributor
Replace downstream o2 sensor
If these 2 parts don’t fix the problem, I’m not sure what to do next. I just wish my check engine light would come on to help point me in the right direction. Seeing how it runs good when cold but not hot. I keep thinking the EGR valve is malfunctioning. When I took off the EGR there was carbon build up in the ports. I cleaned the ports out and sucked on the vacuum outlet to check that the valve was moving freely and engaging under vacuum.
Don’t replace the downstream O2 sensor. It has nothing to do with engine performance. It only monitors catalyst effeciency.
When the engine is started cold, there are four primary inputs into the computer. These are the crank sensor, the coolant temp sensor, the MAP sensor, and the throttle position sensor.
So if the engine runs fine when cold, there’s not a problem with these sensors.
I used to wash the engine in my early 70’s Ford truck at one of those do-it-yourself car washes where you use a pressurized wand. Mostly it wouldn’t cause a problem, but from time to time something in the high voltage circuit would get wet and it could take 4-5 days of driving for whatever it was to dry out. The symptom was rough idle, missing, and stalling. I think that’s what happened in your case, and something in the high voltage circuit remains damp. Probably what I’d do is just wait, and hope it goes away after a few days of daily driving. If I didn’t have the patience, I remove all the high voltage parts – the coil(s) , spark plug wires, spark plugs, distributor cap, and let them dry out in the sun a couple days, reinstall, see if that fixed the problem.
There is a slight chance you’ve cracked the throttle body, intake manifold, head, or the block with the cold water. This could cause all sorts of problems as you might expect, depending on what part cracked and where. I’ve never spray-washed my Corolla engine for this reason, as it has aluminum intake parts, which I expect are far easier to thermal-crack than iron. My Ford truck is iron all the way.
"These are the crank sensor, the coolant temp sensor, the MAP sensor, and the throttle position sensor.
So if the engine runs fine when cold, there’s not a problem with these sensors."
In my experience, the coolant temp sensor usually fails in a manner that always shows the temp as cold. The engine runs fine when it IS cold but then runs rich when actually warm because the ecm continues to apply the enrichment mode.
Based on the other information given here, it doesn’t sound like an enrichment problem. However, in general I don’t think you can rule out the temp sensor if an engine runs correct when cold.
Kind of like hosing out your DVD player and expecting it to work properly…
I learned my lesson the hard way when I took a pressure washer to my Crown Vics engine compartment. Cost me 3 ignition coils (COPS)…With today’s electronically controlled cars, washing the engine is risky business…Good Luck…
I have a 2007 audi A4 2.0T and I’m having the identical issues as described above. Its been 2 days since the engine clean (someone else did it without consulting me first). Any suggestions? I took apart every electrical connector i could find and sprayed with Wurth electrical connector spray. I did notice moisture in #1 & #4 coil pack.