Possible intake valve stuck open

[Redog]

As the title states.

Back in July my car broke down just outside North Wildwood, NJ and I ended up having it towed back home to Philadelphia (90 miles, good thing for AAA)

Anyway, I thought it was the injectors, replaced them, same issue. I swapped the coils, ICM, plugs, and plug wires. The misfire did not move from #4.

The #4 header is cool to the touch. Yes you can touch it with the engine running. It's popping thru the intake.

There is no loaner tool for compression checks or leak down checks around here. I looked it up on youtube and saw a few cars with an intake valve stuck open making the same exact noise

Really don't want to remove the head. Is there anyway to fix this issue with the head still on the engine? I was going to pop the valve cover and try cranking the engine (take out fuel pump relay and unplug ICM) and see what happens, mainly with number 4, or maybe turn it by hand.

History of the problem:

Car sat in the garage for 6 months over the winter. Sta-ble in the tank. Took the car to work a few times in April and in June. Then took the car out in July for a few days before going down the shore. Probably put about 300-400 miles on the car before this happened. The car did get poor MPG's that entire week

[a.graham52]

If it was mine, I would pull the valve cover and inspect the calve to verify it is indeed stuck. If it is and the push rod is still intact and not bent, then maybe try seafoam the oil and fuel. GM has a bulletin out for most vehicles about carbon buildup on the valves causing them to hang open. If carbon has built up on the valve head keeping it open, sea foaming the intake my be the way to go... Gm parts has a rugged intake cleaner you could try too.

[Redog]

OK, is Seafoam a safe product to run in the oil? Do I have to change the oil afterwards? I know it smokes like crazy during the process

[a.graham52]

Originally Posted by Redog

OK, is Seafoam a safe product to run in the oil? Do I have to change the oil afterwards? I know it smokes like crazy during the process

It's a detergent. It will clean potential sludge in the oil. U out it in. Drive a half hour or so and then do your oil change. Adding seafoam to the oil does not produce the smoke show. You get that when u introduce seafoam to your intake and it gets burned thougj the engine.

My thought is if you put a bottle in the oil, a bottle in the fuel and a bottle though the intake, you will have attempted to clean every aspect of that valve. Clean oil slugs build up inside the valve cover potentially, clean carbon off the valve stem/head by going though the intake, and a long term application by introducing seafoam into the fuel and consequently the injectors.

[a.graham52]

Don't be afraid to run the engine for a very short period of time without the valve cover. It will be messy but gives u a good chance to see the valve train in question, in action. I wouldn't run it for more then 20 seconds or so at a time. Maybe even put some cardboard over the headers to keep them as clean as possible

[sleepyalero]

Run sea foam in oil for 100 miles then change oil.

[Redog]

The Alero doesn't see 100 miles that much anymore

[Redog]

Plus the car is not drivible at all.

[a.graham52]

if its just not driveable due to the skip, then thats not a big deal. drive it around anyways for a couple short trips and just me mindful not to drive it too long if the check engine light flashes. its not an interference engine so if the valve was to hang wide open (which its probably not) then it still shouldnt cause any damage machanicaly.

[3500Alero]

Pull the valve cover and take a look at the rockers. I had the #4 rocker stud pull the threads out of the head in my Alero years ago. I was able to put a helicoil in it and never had a problem after. Think it may have been caused by over torquing the rocker when replacing the intake gaskets.

[jawa]

i bet the rocker backed out