Hotsoak on the M50 - which vacuum line and where is it?

[RobPatt]

I'm ready to take the hotsoak plunge and see a difference. Which vacuum line, and where is it? Thanks. -Rob '93 525ia@131K

[ryan roopnarine]

I'm ready to take the hotsoak plunge and see a difference. Which vacuum line, and where is it? Thanks. -Rob '93 525ia@131K

in all honesty, i didn't see an improvement (noticeable) until the second treatment, and i don't think you will either. i find that a much more aggressive, yet less hard on the engine method for cleaning is either one or two cans of berryman's b12 on 2.x or less gallons of gas, italian tuneup'd to the point you are comfortable before you run out of gas, repeat (at least 2 or 3 times). i can't find any lubro moly sauber specifically for valve cleaning here in BFE, and you can only find combo fi/valve cleaner at autozone. how do i know the b12 is effective? everytime i do it, it pushes the o2 sensor out of range for a little while and there's detectable carbon in there after doing it. this is something that didn't happen with the water treatment. i'll see what the verdict is after 5-8 treatments. the stuff is made of xylene so i'm not too concerned about the aromatic aspects of it killing an o2 sensor, and best of all, it only costs 2.30-3 per can, which is cheaper than a 40-60-80 dollar FI cleaning. if i had a mech. like bill r around that could give me a strategy for getting it out, and a reasonable estimate, i might have a pro do it, but that doesn't seem like its going to happen, and i'm not fond of the idea of having to take it back for FI cleanings at 40 a pop until its clean.



ps....the line you pull to suck water/solvent is the FPR hose, (not the manifold side). i find that a length of aquarium tubing fits nicely into this hose for extension.

[RobPatt]

I'm thinking of pulling the plugs and squirting an ounce or 2 into a few cylinders, run it, and repeat w/the remaining cylinders... maybe then the hotsoak, then the italian tune-up. My piston heads look powercoated black, and 90% of my driving is under 45mph and 5 miles or less....


in all honesty, i didn't see an improvement (noticeable) until the second treatment, and i don't think you will either. i find that a much more aggressive, yet less hard on the engine method for cleaning is either one or two cans of berryman's b12 on 2.x or less gallons of gas, italian tuneup'd to the point you are comfortable before you run out of gas, repeat (at least 2 or 3 times). i can't find any lubro moly sauber specifically for valve cleaning here in BFE, and you can only find combo fi/valve cleaner at autozone. how do i know the b12 is effective? everytime i do it, it pushes the o2 sensor out of range for a little while and there's detectable carbon in there after doing it. this is something that didn't happen with the water treatment. i'll see what the verdict is after 5-8 treatments. the stuff is made of xylene so i'm not too concerned about the aromatic aspects of it killing an o2 sensor, and best of all, it only costs 2.30-3 per can, which is cheaper than a 40-60-80 dollar FI cleaning. if i had a mech. like bill r around that could give me a strategy for getting it out, and a reasonable estimate, i might have a pro do it, but that doesn't seem like its going to happen, and i'm not fond of the idea of having to take it back for FI cleanings at 40 a pop until its clean.



ps....the line you pull to suck water/solvent is the FPR hose, (not the manifold side). i find that a length of aquarium tubing fits nicely into this hose for extension.