A couple of weeks ago in an effort to locate some oil and water leaks I gave my engine bay a thorough washing at the public car wash.

The drive home it was fine. The next day was fine. The day after that I noticed one strange shift but no further problems. The day after that I started to experience what felt like misfires at cruising speed. The next day the car began shifting erratically; there was no way to know what gear it might be in at any time, if it would change gears, or be in a gear at all. I parked it for a couple days and took it for another drive with no issues.

The day after that the check engine light came on with a code for shift solenoids. The next day I was driving without issue when I suddenly lost all the gears and coasted to a stop. After restarting the car a few times I was able to get it moving again, and would have to keep coasting to a stop and restarting the car to get it home. The past few days I've been able to move the car for about the first 3 minutes after a cold start before becoming stranded again.

So to recap, no issues at all before the car wash, then slowly symptoms begin appearing until days later they render the car useless.

I'm just not buying that the solenoids went bad since the problems began shorty after the wash. The transmission was rebuilt 2 years ago and I've put fewer than 5000 miles on since.

I've taken the connectors of the main wiring harness off and cleaned the ends with electronic contact cleaner, as well as cleaning the connection to the computer.

Has anyone experienced this or have any idea what my next move should be? I hate to go to the work and time of changing the solenoids and have them not be the cause of my problems. I've considered buying a replacement computer and new wiring harness but again, I don't want to waste the money if those aren't the problem.

But I have found the leaks. My rear valve cover and oil pan are leaking, and the water is pouring out of where the throttle body and intake meet when I first start the car, so I'm assuming that's the infamous intake manifold leak.

My problems are also paired with a horrible buzzing noise that is audible from inside the car when driving that I can't quite locate but appears to be coming from the transmission/throttle body area. The sound comes and goes and changes with the revs regardless of being in-gear.

So now with the information in the above paragraph, is this car just a lost cause? I don't mind doing the work, but I do mind throwing money at parts and stuff.

Thank you for reading and for any replies.

 

Did you cover your alternator? I have a brother who used to wash his engines, and got the alt drenched one time and he was stuck at the carwash... Though it sounds more to me like you may have knocked off a spark plug wire, or loosened it, even got it wet. I'd remove all plugs and wires dry them out, and give that a try, maybe its time for a swap anyhow? Another thing to check is emissions hoses, filter box, anything that you 'shot-up' while washing, etc... same concept. All that pressure from the hose can sneak into places.

 

Its never a good idea to "power wash" the engine bay... Especially with these computerized vehicles. There may have been an open short to the transmission leads ...Once you drenched/power washed it under the hood theres no telling what other electrical issues may turn up... It could be something as simple as a vacuum leak somewhere... Not knowing what state your from ... If your like us in the east its been freezeing cold temps..
Its quite possible, that the water/moisture freezes up over nite ..Once it warms up the dew/ice melts and once again the problem returns...
Theres a way to check for vacuum leaks... Start the vehicle (don't drive it) let it get warmed up.... Take a spray bottle of water on mist and spray around the vacuum and electrical lines... Its quite possible you have some bad wires or even a cracked/bad coil/s. When it starts to misfire you have found where the leak/short is.... This test is not recommended...if the water misting doesn't work around the vacuum lines.... Use Ether and spray it around the vacuum lines...(Only)
When the motor revs/starts shuttering, You have found the leak...

I do however...first and foremost recommend you change the upper and lower intake gaskets... along with flushing out the cooling system and do an oil change immediately after the repair... This may also be a contributing factor to everything that's going on.! Does the fluid in your radiator look like its a milk shake? also check the oil filler cap on the edges underneath it and look for the same milkshake colors...even in the valve cover itself!... also you will need to change out the coolant elbows that are connected to the tensioner pully (**** poor design by GM) as they are plastic and wear out/ (heat up corrode) and crack... We recommend you get aluminum ones.. and don't use the supplied O rings in the kit..get aftermarket O rings from your local auto parts...as the ones supplied shrink and leak over time.

I'm sure others will chime in with more ideas as well...
But this should get you pointed in the right direction!

 

It's hard to tell since you soaked everything with a pressure washer (as stumpmi said)

Three trans sounds like a line pressure issue but there is many things that could make that happen. Inspect all wires very closely and spray water mist like stumpmi said.

 

I realize I left a few details out. I've got a 2000 SS, 170k miles, and live in Phoenix.

I suppose for clarity I shouldn't have mentioned a misfire, I was only saying that that's what it felt like, but now I know it was the transmission screwing up. The main issue, before I mess with anything else, is to get the transmission working again.

Like I said, I'm just having a hard time believing that the solenoids went bad (even though they are throwing engine codes, TCC being the most common) in a transmission with fewer than 5k miles on it, and because the problems slowly started increasing with intensity in the days after I got everything wet. Most of the focus of the wash was on the lower part of the engine and blasting up from below the car; I did take some care in what got wet.

Does it make sense that I could go out now and start the car and drive it for about three minutes before I end up coasting to a stop and have to let it sit until it cools off again and hope that I'll be able to move it? Wouldn't bad solenoids be bad all the time? Shouldn't a physical problem be present all the time? That part has me leaning towards a problem at the computer possibly induced from water on a connection somewhere causing a short.

I do like your suggestions of vacuum leaks.

 

It could have also been a shotty rebuild job and the solenoids weren't replaced... Maybe he only did a soft rebuild? Did a shop rebuild it or did you have the dealer do it? It may have nothing to do with the wash down at all!... I would take it to a reputable trans shop (someone trust worthy) and have them scan the trans for trans codes (separate from the obdII port reading) Then youll know forsure that its a solenoid issue! Other wise take it back to the trans shop and tell them whats going on.... Does it have a warranty?... Or was the trans replaced with a used one from a boneyard?

 

First thing, check fluid levels and color. After that, The way you are describing it really sounds like solenoids. They will fail and become stuck when warm, then reset when they cool down. Could be dirty, or could be bad. Maybe try to use some seafoam trans tune to clean it up and unstuck the solenoids. Put the trans tune in the trans and drive it around the neighborhood a few times with the inn and off trick. See If it cleans it up, if it does drop the pan, change the filter and fluid and see how it holds up. If it doesnt it could be a shift soleniod. They dont always replace those when they do a rebuild.

 

Me trans was doing this when my clutches were toast. Clutch mud clogged the filter etc and would slip and not move. Once cooled down the trans fluid was thicker and would work until it got warm then would slip again. I agree with solenoids as well though.

 

Good responses. Thanks guys! The fluid looks good and is at a good level but I'll try some Seafoam and see what happens.

 

You can also use the Lucas Stop Slip for your tranny, it thickens the viscosity and removes the gunk from sticking valves. Has worked great on my ZR2 S-10 and my full size GMC. I have been running my tranny's on borrowed time for a couple of years now, sometimes the tranny would get so hot, fluid would come up and out the tranny filler tube. So they were getting bad, my mechanic said if the Lucas works, use it till they fail, it's essentially "Free miles" as he puts it. I just don't romp them and they still run to this day.