[Kyle335D]

I received a quote from a local shop to do the CBU cleaning for $500 on the 335d. He told me that they use a chemical process for the intake and head and there is no walnut blasting required. Does this sound a little fishy, anyone else have theirs done this way?

[Torqu3]

I remember reading something about this awhile back, and that it wasn't as good of a clean. That said, plenty of people here DIY the intake by dunking it in a trash can full of purple power and then power washing it.

[Kyle335D]

Originally Posted by Torqu3

I remember reading something about this awhile back, and that it wasn't as good of a clean. That said, plenty of people here DIY the intake by dunking it in a trash can full of purple power and then power washing it.

Yea I figured it wouldn't be as good as a walnut blast. More concerned about the cleaning of the valves.

[charlie fairmont]

It's not clear to me from what's been said--will he pull the head for his method?

[Kyle335D]

Originally Posted by charlie fairmont

It's not clear to me from what's been said--will he pull the head for his method?

He did not distinguish when I was talking to him. I'm assuming probably not.

[charlie fairmont]

Hmm. I'd want some more details before handing my car over if I was you.

[335dsleeper]

No one is pulling the head on an M57 for $500.

He's likely going to clean the manifold in a tank and try to clean the runners and valves with the chemical solution. Depending on the amount of CBU, it may not be as good as walnut blasting.

Originally Posted by charlie fairmont

It's not clear to me from what's been said--will he pull the head for his method?

[JTC1]

Here is a question I have been thinking about. If the cheapest a CPU cleaning can be done is $500, but likely closer to $800 or $900, and water/meth injection has been proven to clean CBU (I think it has right?), why not forgo a CBU cleaning and just add meth injection? Unless the car is to the point of throwing a bunch of codes and has too be cleaned immediately, seems like the meth injection would be money better spent. Plus you get the added HP. Am I missing something in the equation? Are there any down sides to running meth other than having to maintain the system? These are all questions I have as I debate adding meth injection at some point this summer.....

[lnxguy]

How much meth do you need to run in order to get everything spotless? I realize that meth + EGR delete keeps things clean, but has anyone gone with meth only and done a visual after say 6 months to see if CBU is reduced or gone all together? A lot of assumptions out there.

[Kyle335D]

Originally Posted by JTC1

Here is a question I have been thinking about. If the cheapest a CPU cleaning can be done is $500, but likely closer to $800 or $900, and water/meth injection has been proven to clean CBU (I think it has right?), why not forgo a CBU cleaning and just add meth injection? Unless the car is to the point of throwing a bunch of codes and has too be cleaned immediately, seems like the meth injection would be money better spent. Plus you get the added HP. Am I missing something in the equation? Are there any down sides to running meth other than having to maintain the system? These are all questions I have as I debate adding meth injection at some point this summer.....

I agree I would love to run meth right after getting it cleaned however, it still has a 3 year extended warranty. In addition I don't think running meth now is going to do anything to break down the carbon that has already built up.

[JTC1]

Originally Posted by Kyle335D

I agree I would love to run meth right after getting it cleaned however, it still has a 3 year extended warranty. In addition I don't think running meth now is going to do anything to break down the carbon that has already built up.

There have been some posts that indicate that running the meth does in fact do a good job of cleaning CBU, but I'm not sure of to what extent. I'll try and find the previous discussion.....

BTW, I wasn't questioning your decision to do CBU cleaning, I'm just at the same point you are and am trying to decide what the best option are.

[Kyle335D]

Originally Posted by JTC1

There have been some posts that indicate that running the meth does in fact do a good job of cleaning CBU, but I'm not sure of to what extent. I'll try and find the previous discussion.....

BTW, I wasn't questioning your decision to do CBU cleaning, I'm just at the same point you are and am trying to decide what the best option are.

Absolutely wasn't disagreeing with you, If I could throw on a meth kit and just drive and clean it out that would be preferable. I just recall a lot more comments saying that meth won't clean it out just help it stay clean. Who knows

[charlie fairmont]

Originally Posted by 335dsleeper

No one is pulling the head on an M57 for $500.

He's likely going to clean the manifold in a tank and try to clean the runners and valves with the chemical solution. Depending on the amount of CBU, it may not be as good as walnut blasting.

I agree and that's what I was getting at, with regards to the OP's question of fishiness--it was too low of a quote to pull the heads and I wasn't sure it sounded safe to pump chemicals into a head still attached to the block. If the chemical is capable of dissolving build-up, I would be concerned some could find its way into the combustion chamber and break down the engine oil. I understand it shouldn't, but it seems like it could.

I'm in for updates and curious to hear what the OP finds.

[335dsleeper]

There's no difference between putting chemical solvents or walnut shells in the head. You'd take the same precautions to ensure nothing enters the combustion chamber, the same as you would if using the walnut shells. Removing the head for CBU would be enormously expensive and completely unnecessary.

There are threads on this forum where guys have had success with chemical treatments for CBU.

Originally Posted by charlie fairmont

I agree and that's what I was getting at, with regards to the OP's question of fishiness--it was too low of a quote to pull the heads and I wasn't sure it sounded safe to pump chemicals into a head still attached to the block. If the chemical is capable of dissolving build-up, I would be concerned some could find its way into the combustion chamber and break down the engine oil. I understand it shouldn't, but it seems like it could.

I'm in for updates and curious to hear what the OP finds.

[Torqu3]

Originally Posted by JTC1

Here is a question I have been thinking about. If the cheapest a CPU cleaning can be done is $500, but likely closer to $800 or $900, and water/meth injection has been proven to clean CBU (I think it has right?), why not forgo a CBU cleaning and just add meth injection? Unless the car is to the point of throwing a bunch of codes and has too be cleaned immediately, seems like the meth injection would be money better spent. Plus you get the added HP. Am I missing something in the equation? Are there any down sides to running meth other than having to maintain the system? These are all questions I have as I debate adding meth injection at some point this summer.....

I've had the exact same thought. My only issue with meth is I remember hearing at one point that if you run meth with your DPF intact, the meth lowers the exhaust temperature too low and it messes with the DPF's ability to regen. If this isn't the case, somebody please correct me so I can justify installing a meth kit. Also, for anyone who does run meth, what is your monthly/weekly cost on running meth?

[charlie fairmont]

Originally Posted by 335dsleeper

There's no difference between putting chemical solvents or walnut shells in the head. You'd take the same precautions to ensure nothing enters the combustion chamber, the same as you would if using the walnut shells. Removing the head for CBU would be enormously expensive and completely unnecessary.

There are threads on this forum where guys have had success with chemical treatments for CBU.

Again, I think we're in agreement. I understand taking precautions and that it has been done successfully. But there is at least one thread where a guy said he started his car afterwards and had rough running issues because he was pretty sure he goofed a bit and got some shells in the chamber. I'd rather have that goof than the goof of oil-stripping solvents. My point to the OP is make sure you're comfortable with the mechanic's capabilities and his assurances that he'll be able to get all the solvent out.

[lnxguy]

A bit is solvent in the combustion chamber isn't going to harm a thing.

[335dsleeper]

It depends on what a bit of solvent is... If you get a bit too much you will hydrolock the engine on the first crank.

Originally Posted by lnxguy

A bit is solvent in the combustion chamber isn't going to harm a thing.

[lnxguy]

Originally Posted by 335dsleeper

It depends on what a bit of solvent is... If you get a bit too much you will hydrolock the engine on the first crank.

Well yeah, pouring cups of any liquid in there would be a bad idea, lol.

[335dsleeper]

Originally Posted by lnxguy

Well yeah, pouring cups of any liquid in there would be a bad idea, lol.

How much solvent do you think you'd need to clean the ports/ valves?

And FYI, it doesn't take much fluid to hydrolock a cylinder... far less than "cups"

[Built4Sin]

Blew a turbo on my TDI... Lost all boost, smoking like a freight train within seconds filled up the cylinders with oil as I shut it down. Changed out the turbo, removed the glowplugs and turned over the engine.... Thats how you get oil on the front of your house and roof! But it was good to go afterwards!

[lnxguy]

Originally Posted by 335dsleeper

How much solvent do you think you'd need to clean the ports/ valves?

And FYI, it doesn't take much fluid to hydrolock a cylinder... far less than "cups"

No idea, but how much is too much to be left behind? We're also not assuming that any of this is going to evaporate before the engine is put back together and started? So many 'ifs' in this scenario that it's pointless to even talk about it.