Need a unique solution for a uniquely dumb mistake

[NeedsHelp]

Hey folks - I'm hoping some of you experts can help me out here.


THE PROBLEM
I have a 2016 VW Tiguan. These cars are known for carbon deposits on the intake valves that eventually cause misfires. Last week, I was using a walnut blaster to clean these deposits (REALLY bad deposits by the way - 109k miles). All was going really well until I made a REALLY stupid mistake.

On cylinder 2, I forgot to turn the engine over to get it to TDC. As a result, the carbon and walnuts sprayed into the cylinder. I was able to shop vac out the walnuts. Then, I tried to turn over the engine... and to my dismay it won't make it all the way up to TDC.

A borescope revealed that carbon had been compressed between the piston and the head when trying to turn the engine over (by hand with a ratchet -- NOT with the starter motor). That carbon is interfering between the piston and the cylinder head, preventing me from fully turning the engine over.

WHERE I NEED YOUR HELP
I am searching for chemical solutions that can dissolve the compressed carbon when soaking in the cylinder chamber. It needs to be able to DISSOLVE the carbon in the liquid because I can not scrape all parts of the head/piston through the available access points. I am hoping I can soak and vacuum enough of this gunk out to at least turn the engine over.

Any recommendations on what might work here? I've read that products like Chemtool B12/B60, Chevron Techron, Gumout, etc may work. What I can't tell is if these products require the combustion process to clean or if they would be able to dissolve carbon into the liquid so I can vacuum it out.

I would honestly be willing to take a risk on something ridiculously strong (e.g. paint strippers) and see what happens. Also open to other ideas that don't require me removing the head

 

[AdmiralYoda]

Berryman B12 is great at dissolving carbon. Many of us do piston soaks to free up stuck rings. Is this a 4cylinder? That would make it easier to fill the cylinder.

Keep the piston covered with B12. Check with the borescope often and keep adding more B12 if necessary. Let it sit overnight and then use a fluid extractor to suck out the hopefully dissolved carbon. May need to repeat it a few times.

When you think you've got it all spray some penetrating oil or some other lubricant in the cylinder to lube up the rings. Turn the engine over by hand a few times to make sure nothing is binding. Verify there is no liquid left in the cylinder....then start her up!

 

[kschachn]

You aren’t going to dissolve carbon.

 

[thastinger]

Hey folks - I'm hoping some of you experts can help me out here.


THE PROBLEM
I have a 2016 VW Tiguan. These cars are known for carbon deposits on the intake valves that eventually cause misfires. Last week, I was using a walnut blaster to clean these deposits (REALLY bad deposits by the way - 109k miles). All was going really well until I made a REALLY stupid mistake.

On cylinder 2, I forgot to turn the engine over to get it to TDC. As a result, the carbon and walnuts sprayed into the cylinder. I was able to shop vac out the walnuts. Then, I tried to turn over the engine... and to my dismay it won't make it all the way up to TDC.

A borescope revealed that carbon had been compressed between the piston and the head when trying to turn the engine over (by hand with a ratchet -- NOT with the starter motor). That carbon is interfering between the piston and the cylinder head, preventing me from fully turning the engine over.

WHERE I NEED YOUR HELP
I am searching for chemical solutions that can dissolve the compressed carbon when soaking in the cylinder chamber. It needs to be able to DISSOLVE the carbon in the liquid because I can not scrape all parts of the head/piston through the available access points. I am hoping I can soak and vacuum enough of this gunk out to at least turn the engine over.

Any recommendations on what might work here? I've read that products like Chemtool B12/B60, Chevron Techron, Gumout, etc may work. What I can't tell is if these products require the combustion process to clean or if they would be able to dissolve carbon into the liquid so I can vacuum it out.

I would honestly be willing to take a risk on something ridiculously strong (e.g. paint strippers) and see what happens. Also open to other ideas that don't require me removing the head

Find a station that sells E85...not flex fuel...E85. Pour that in there, let sit then vacuum out while still liquid. Rinse and repeat as necessary.
I'm sure brake cleaner would also work, would just be more expensive and potentially more corrosive to engine internals.

 

[threeputtpar]

Pull the plug and stick a long narrow blow nozzle in there and turn your compressor to max PSI and go to town.

Whatever it doesn't blow out, try the vacuum again and then use a chemical soak for what's left in there.

 

[spasm3]

I'd use a blowgun through the spark plug hole, and try to move stuff around so the piston has room, once is starts, it will go out the exhaust valve which is not a problem, unless you have a turbo, then you might have a problem.

 

[NeedsHelp]

Great idea folks. I might combine your ideas and soak it for a couple of days in B12, vacuum out the liquid, THEN blow it out with a compressor. This will blow out the intake valve since I'm stuck on the intake stroke (which is probably better anyways...)

Rinse and repeat. Wish me luck

 

[panthermike]

Great idea folks. I might combine your ideas and soak it for a couple of days in B12, vacuum out the liquid, THEN blow it out with a compressor. This will blow out the intake valve since I'm stuck on the intake stroke (which is probably better anyways...)

Rinse and repeat. Wish me luck

Let us know how it works out, best of luck to you.

 

[Cujet]

A zip tie on the end of a dowel or aluminum rod. Chuck it up in a drill and mechanically break up the deposits. Done correctly, it will work.

 

[NeedsHelp]

A zip tie on the end of a dowel or aluminum rod. Chuck it up in a drill and mechanically break up the deposits. Done correctly, it will work.

Interesting... I'm going to give it a shot after the chemical soak. Great idea.

 

[shortyb]

A zip tie on the end of a dowel or aluminum rod. Chuck it up in a drill and mechanically break up the deposits. Done correctly, it will work.

Zip ties work really well. I used to use about 20 bunched together to break up IVDs, along with a liquid soak, before I got the walnut blaster. Combine that with a Chemtool B12 soak, suck out the muck, and you should be good.

 

[Nukeman7]

Find a station that sells E85...not flex fuel...E85. Pour that in there, let sit then vacuum out while still liquid. Rinse and repeat as necessary.
I'm sure brake cleaner would also work, would just be more expensive and potentially more corrosive to engine internals.

If you choose to vacuum out any flammable solvent, don't use an electric Shop Vac! Instead, use a Mityvac style extractor to preclude a fire or explosion from the fumes.

 

[The_Eric]

I'm in the camp of trying to blow it out. I would try doing that first, as opposed to after the chemical soak, so it remains consolidated. Use a dowel or equivalent to break up the pieces and attempt to vacuum the remainder

 

[D60]

Do carbon deposits float in gas? If so can you flush/float it out?

 

[tiger862]

Brake Cleaner. Soak then change oil before you start vehicle. Run up to temp and change. You can use cheap oil and filter for first oil change.