Cleaning Intake Valves - Hands ON

[DesertEagle]

I've pulled the valve cover, throttle body, upper intake manifold, and lower intake manifold.  My intake valves are pretty gummed up with black residue.  I put mineral spirits in the closed intake valves (1,2,3), covered the engine, and let it sit overnight.  The next day, I turned the engine over with a ratchet to drain the mineral spirits.  I repeated the procedure again on cylinders 2,3,4.

While the intake valves are noticeably cleaner, I did this procedure mainly to see if any intake valves were leaking.  They're not.  I think I ought to clean the intake valves since I've gone this far.  I don't have another reason to pull the head, so I'd rather not.

I have two ideas:
(1) Buy the flexible extension for my dremel (actually the comparable craftsman pos) and use the abrasive buff (softer than a brass wheel) to polish the back of each intake valve in the open position.

(2) My fuel rail is about 6 inches lower than the bottom of the oil pan.  The fuel hoses are connected, so the only way gas vapor can escape is where the fuel injectors sit in the fuel rail.  The evap canister valve is closed, too.  The oil is drained from the engine.

How risky is it to use a propane torch to heat up the back of each intake valve to burn off the carbon?  My thinking is that the risk is minimal.  But I also think that if someone on this forum suffered an untimely demise caused by using a torch near an engine, I'd nominate him for a Darwin Award:eek:.  So, I'd just like to understand the risks before I make a decision.  Thanks.

[flyinglizard]

You would stand a good chance of scratching the valve sealing face. Leave it alone.
  Run some Techron thru it. Maybe carb cleaner siting  in the holes, blow it out the next day.  I would avoid the heat thing..
 VW had a recall that used  walnut shells blasted into the back of the open valves. Vacuum out of the plug hole, blow it out , etc.  Worked.
 MM

[DesertEagle]

You would stand a good chance of scratching the valve sealing face. Leave it alone.
  Run some Techron thru it. Maybe carb cleaner siting  in the holes, blow it out the next day.  I would avoid the heat thing..
 VW had a recall that used  walnut shells blasted into the back of the open valves. Vacuum out of the plug hole, blow it out , etc.  Worked.
 MM

When you say run techron through it, you mean by adding it to the gas tank, right?  I'm installing the mustang injectors recommended on this forum.  I kinda feel that if I run techron enough to clean the valves, I might be damaging the fuel injectors.  I look into the car cleaner.

[BlueBMW]

Techron shouldn't damage your injectors, if anything it will help them.  Just use good quality gas and run some techron through every now and then and your valves should clean up nice.

[PumpItUp]

cough lubro moly fuel injector cleaner cough cough better than gas station crud
oh wait you already cleaned your injectors by hand so it doesn't matter.
wait why not just buy valve cleaner then :confused:
http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/usa_gasolineadditives_nt00005422.html

i think half of those products are banned in the US for being too toxic. so check which ones are available on bav auto, etc. the ones that i have tried were still very toxic and i felt like i should of been wearing a radiation suit. worked great as opposed to the placebo's they sell at the local parts chains. after i used the engine flush (the ones which you run for 5 mins before an oil change), the profile cover gasket was done a week later and everything looked brand new, 100k+ motor and non of the usual discoloring.

[DesertEagle]

So I've picked up the theme that I should let a detergent/solvent/cleaner do the work.  That leaves me with two options (1) apply directly to intake valves, or (2) add to gasoline regularly.

It's tempting to apply directly, because the product is localized to the effected area.  But on the other hand, if I don't aspirate the solvent, it will be washing through the cylinders.  Granted, I've already washed a few ounces of mineral spirits through, but some of the lubro-moly stuff is potent.

I don't know what to do.  I've never opened an engine before, but two friends that have say the intake valves are heavily gunked.

I'm not sure about the engine flush.  The valve train and what I can see of the engine block are gunk free.  They don't appear to need cleaning.

[PumpItUp]

the only time i remember seeing milkshake style sludge/gunk like they dramatize on the commercials is on a 1980s toyota. oil was a lot less advanced back then, plus the previous owners were cheap bastards/irresponsible retards with relation to oil changes, and lastly it was a toyota so it actually ran long enough for me to see this sludge. but i think any engine with more a a few years old will have something, just that little bit of sticky on the side walls, etc. and that engine flush is good stuff. on the other hand any time you run anything besides gas & oil in your car, you're taking a risk, especially the ones that deal with oil. even if products (the good ones) are much safer than they were 20 years ago. all of it can't be drained (or can it... if you leave it overnight for example). what are you going to do, flush it with motorclean, then flush it again with $20 worth of new oil, before filling up for the final time with more new oil. seems extreme unless you work at a lube place. the safest & most effective way is still to spend the hours and clean everything by hand.

[flyinglizard]

If you use Rotella syn, Mobil one syn, or Syntec, The engine will not have any crap inside it anywhere, for ever.  Regardless or miles. . MM

[DesertEagle]

If you use Rotella syn, Mobil one syn, or Syntec, The engine will not have any crap inside it anywhere, for ever.  Regardless or miles. . MM

I thought the deposits on intake valves are fuel-related.  You're telling me that the engine oil is responsible?

[pbgd3skier]

I thought the deposits on intake valves are fuel-related.  You're telling me that the engine oil is responsible?

Remember that your engine draws its own oily residues back through the intake and then reburns them.  This residue can really be a mess as far as gumming things up.

The line from the valve cover under the intake, and to the throttle body is the source of this rebreathing.

Its all sort of a emissions thing, not from the exhaust but from the engine in general.  If you hang around old cars you'll notice they have a stench.

[deekay]

Seafoam is supposed to help with this, isn't it?

[DesertEagle]

Seafoam would because it's drawn in by engine vacuum from the brake booster hose.  I've never heard anyone question the effectiveness of Seafoam.  In fact, all the gunk it blows out your exhaust is known to kill O2 sensors and mine is new.