De-carb with plain old water

[jmgtp]

Tomorrow is the big day. Going for my re-Etest on my LX9 swap.

It failed its original test (months ago) for very high NOX, which to the best of my knowledge is the chemical compound created due to elevated cylinder/combustion temps. Bring down the cylinder temp and the NOX will drop. It did pass HC and CO limits.

Since that test, a major motor issue has been corrected (was running on 5 cylinders before, due to a misplaced pushrod). An EGR valve has been installed which should in itself drop NOX levels. It has a newish (6 months old) 3 way catalytic converter (this was present on the original test).

I think the proper running motor, the addition of the egr valve and more tuning should result in a pass. However, I still worry. I want to de-carbon the engine tonight. My logic is that any carbon deposits on the piston tops and cylinder head can increase compression and more compression equates to more heat and NOX.

I want to use plain old water. I live in a condo complex and the Seafoam cloud will likely result in police at my door. I did some Google research and saw some pretty amazing results from just water.

The big question I need answered is how much water do I feed through a vacuum line and at what rate? In other words, a quart? a gallon? Over 5 minutes? 10? 30?

I'm thinking I will either use the small FPR vacuum line or the PCV line as the draw source for the water.

[pocket-rocket]

I know Lorenzo will swear by water too, but I've never watched how much he added. I'm pretty sure he fed his engine about a 20oz. bottle and I don't know if he used a vacuum line or attempted to dump it through the TB. I imagine if a couple bottles would do it and I would use any line that a can of Seafoam or GM TEC would use. I wouldn't want to use a FPR line though since undoing that would spike the fuel pressure and run rich at idle.

This is just my $.02, but I haven't done this before.

[Fastmax32168]

I think if you are using a vacum port the answer is going to be as fast as it will accept it. I have used this method many times in the past and have simply poured it into the main intake throat while modulating the throttle at a rate that kept the engine from stalling. I have actually never done it on a motor with a sideways intake throat so have never used a vacum port. I think it will probably be impossible to get it in there "too fast" through a vacum port. As to how much, until you feel like stopping.
Roy

[3400-95-Modified]

You can always find the cylinder where a head gasket was leaking due to the steam cleaned piston so yeah I can only imagine how well that would clean up the pistons..

[Superdave]

It works very well, however things can go bad quick. Add a little at a time and you should be fine.

[3400-95-Modified]

It works very well, however things can go bad quick. Add a little at a time and you should be fine.

Treat it like a meth injector and keep the flow low and that will eliminate any issues...

Just don't stuff the vac hose in a 2L bottle.

[TGP37]

Seafoam, when used right, can get rid of A LOT of carbon build up. And you can gauge how much you removed by the level of smoke produced, which is the carbon getting blown/burnt out.

Follow the instructions exactly for the vac line application. Also try adding 1/2 can to 12-15 gallon full tank. It will clean as you drive. You should take it out on the highway and floor it, open her up to RPM max. That will also help blow out carbon build up, especially after a recent seafoam application.

I have never encountered but read about........A stretched timing chain can also increase NoX. From the retarding of the camshaft. So can a bad coolant mixture of water/antifreeze. Which can prevent proper cooling, just like a bad radiator cap with a bad/no thermostat can increase nox as well. Unlikely but things I ponder.


Basically, your combustion temps are exceeding 2300°F if NOX is way too high. Just some ideas in case the de-carb trick doesn't work.

[CNCguy]

AFR ratios over 15:1 or so will raise NOX levels. Is your tune right for the RPM ranges they are checking?

[jmgtp]

Seafoam, when used right, can get rid of A LOT of carbon build up. And you can gauge how much you removed by the level of smoke produced, which is the carbon getting blown/burnt out.

Eh, I don't really buy that the amount of smoke is indicative of the amount of carbon burning off. I think its more like the chemicals in Seafoam burning.

AFR ratios over 15:1 or so will raise NOX levels. Is your tune right for the RPM ranges they are checking?

Tune should be good for emissions now. Lean cruise is Off and EGR is ON. They run it on a dyno at something like 25 mph. That said, I didn't make it to emissions this weekend so no results yet.

I did the decarb with water. About 2 liters total. I used the FPR vacuum line and allowed it to skim the surface of the water so that the hose was never fully submerged. It ran a bit rough (idling) but did not stall and it produced a whole lot of steam out of the pipes. I suppose it worked, it runs the same as before the decarb, which is a pretty smooth idle.

[3400-95-Modified]

I think it's quite obvious as to what the issue was... Almost no car running on 5 cylinders will pass an emissions test cleanly.

Since that test, a major motor issue has been corrected (was running on 5 cylinders before, due to a misplaced pushrod). An EGR valve has been installed which should in itself drop NOX levels. It has a newish (6 months old) 3 way catalytic converter (this was present on the original test).

[jmgtp]

Absolutely agree. But, I'm just doing everything I can to ensure a pass. Which meant adding an EGR, decarbing, etc.

[Azrael]

I did a water/steam treatment by sticking a spraybottle nozzle into the brake booster vaccuum line and slowly pumped the water in. I figured the nozzle would help atomize the water for better distribution but it's hard to tell how well that worked. It took about 7-8 minutes to finish a 1L bottle.

It seems pretty safe to do it this way since I didn't have to touch the throttle to keep the idle speed up.

[Merc6]

Even tho it's just plain water are we still changing the oil and plugs shortly after doing this like when running seafoam?

[pocket-rocket]

I wouldn't see the need. If it seeps past the rings (which it shouldn't after going through the combustion chamber during the combustion event) and enters the crank case it would boil off after the engine reaches operating temperature.