Backside intake valve carbon deposits

[LM]

I spoke to a mech today, who stated that while water, slowly trickled into the intake manifold at medium-fast idle, does a great steam cleaning job on carbon deposits in the combustion chamber area, it doesn't do well on the backside of intake valves

This didn't quite make sense to me, as the backside of intake valves get plenty hot enough to flash/steam/induction water?

He recommended a couple of chemical products, instead. He didn't stock them - wasn't trying to sell me anything - and even let me borrow a can adaptor and small trickle hose to feed whatever chemical product into the intake manifold

Appreciate any comments

 

[Leo]

Redline claim thier SI-1 does a great job of reducing the carbon deposits on valves. Not sure about others...

Btw, Ive seen the backside of very dirty valves. They sure do restrict performance. However Im not sure how SI-1 or anything would remove the junk on them. It would take a file to remove it from what I've seen..

 

[novadude]

quote:

---

Btw, Ive seen the backside of very dirty valves. They sure do restrict performance. However Im not sure how SI-1 or anything would remove the junk on them. It would take a file to remove it from what I've seen..

---

That is my experience as well. Getting my hands on cruddy valves makes me wonder how ANY 12oz bottle of chemicals added to 15 gallons of gas can even touch this stuff.

Anyone have any good facts to prove otherwise?

 

[LM]

quote:

---

Originally posted by novadude:

quote:

---

Btw, Ive seen the backside of very dirty valves. They sure do restrict performance. However Im not sure how SI-1 or anything would remove the junk on them. It would take a file to remove it from what I've seen..

---

That is my experience as well. Getting my hands on cruddy valves makes me wonder how ANY 12oz bottle of chemicals added to 15 gallons of gas can even touch this stuff.

Anyone have any good facts to prove otherwise?

---

Do you recall what types of driveability problems where happening w/the cruddy valves?

This mech, by brief contact, is an above avg one, thought that any stuff you pour into the tank _might_ be of use if the injectors were _just starting_ to foul. Otherwise, as far as the injectors go, pull them for bench cleaning. And thought bottle in the tank stuff did little/nothing for valve deposits.

While something much stronger, into the intake manifold and not thru the fuel system, works for him. No hard data AFAIK - he may have a boroscope (he has a lot of advanced equipment, not for show but for use) - not sure if valve backs can be seen - but it just works for him wrt to suspected build-up and certain driveability issues.

But I'm more curious about whether water will work on valve deposits, and if it works as well or better than chemicals

 

[novadude]

quote:

---

Do you recall what types of driveability problems where happening w/the cruddy valves?

---

None, really. The engine I have in mind is a carbed 350. I yanked the heads to replace a suspected leaking head gasket, and while I was at it, I replaced valve seals. I was amazed at the amount of crud on the intake valves after only 30k miles. I had to chisel it off with a blunt screwdriver.

Car had more power when I put it back together, but I also added a different intake, and higher ratio rockers. I can't say for sure if cleaning the valves helped or not, but I GOTTA believe that 1/4 of crap blocking off the flow cannot be good.

 

[arkainzeye]

would this stuff help out at all?

http://www.seafoamsales.com/motorTuneUpConsumer.htm

 

[TR3-2001SE]

This mech, by brief contact, is an above avg one, thought that any stuff you pour into the tank _might_ be of use if the injectors were _just starting_ to foul. Otherwise, as far as the injectors go, pull them for bench cleaning. And thought bottle in the tank stuff did little/nothing for valve deposits.

Don't know if it cleans the back side of valves or just the injectors but I can assure you it does work. I had an audi that would hardly run and it took about 5-6 tanks of gas with gumout to clean it up. Ran great after the treatments.
My moms buick was hard starting and 1 tank of
the techron cleared it up completely.
I have a feeling it just cleans the injectors not the valves.

 

[Dick in Falls Church]

AMSOIL PI and BG44K (and probably Redline SI) will clean the carbon off the backs of the intake valves.
Doesn't do it in seconds, but after a tank of gas, deposits should be pretty well gone. A tank of gas used in stop and go city driving is more effective than a tank of gas used on the highway. It gives the chemicals a chance to soak in.

 

[sciroccoGTX16V]

SL-1 or Techron will do wonders for the valve deposits when it's sucked thru the intake manifold. If your valves are dirty, you will see lots of smoke in the exhaust.

 

[Dr. T]

I think that in addition to cleaning the injectors, a good F.S. cleaner (plus proper maintenance eg. oil changes) helps keep the valves, lifters, etc. clean and lubricated.

 

[Leo]

Just wondering how a fuel additive can do squat for lifters? The lifter is lubed only by engine oil..

I hear this all the time on the net...

 

[LCD]

lc and fp will cure all these problems

 

[LM]

I just had a brief follow-up conversation w/the mech. He sees a noticeable change/improvement in before & after exhaust gas analyzer #s (we didn't get into the actual #s / details), on those cars in need, and is why he believes in a few different chemical intake cleaning products that he uses (and some of the cars run better afterwards, too).

FWIW, he's currently using 3M product 08958 (about $16 USD), which is also part of a 3 can 'kit' MM8962 (about $28 USD), which includes two other throttle plate and whatever cleaning products (probably other products would suffice).

Note that 08958 requires adapter 08960 for delivery (maybe something else could be fabricated to get the aerosol product into the induction system), and the exhaust will smoke up pretty good! for a few minutes until the stuff has run its course

[ November 10, 2003, 11:25 AM: Message edited by: LM ]