Water decarbonisation

[FCD]

Tried the old trick of water decarbonisation last Sunday on my '75 Capri.

Came back from a long drive, whipped off the air filter box and sprayed distilled water right down the carb using a spray bottle, i used a little over half a liter while holding the engine at 2000-3000rpm.
It wasn't immediately noticeable but i really began noticing it yesterday :

- Idle is smoother
- Acceleration seems more linear and engine seems to rev more freely.

Until August 2016 when i changed the valve stem seals, the engine used a lot of oil, i estimated about a quart / liter every 600 miles, after changing them the oil consumption completely stopped, so i assume the inlet valves are probably very cruddy.

These are ofcourse not scientifically demonstrable, but the butt dyno says it runs better!

Bonus revving video after doing it : https://www.youtube.com/watch?v=dilsdyH5d1Y

 

[Kira]

How many miles/kms are on your Capri?

 

[wander2039]

Did the same on our RV couple weeks ago but haven't drove it yet. The driveway was clean before I started.. and so was my youngest leg. He just happened to walk by right as I hit it lol. Was having issues with pinging. I'll find out the results tomorrow.

 

[billt460]

Is there a down side to this procedure? Can you damage anything like electronic sensors in these modern vehicles? I've heard of water injection used as a way to increase power in older military aircraft. But for some reason spraying water into a running automobile engine doesn't sound like something most should be doing.

 

[csandste]

Bringing back memories here. Bought a '71 Renault R6 new and fell for a JCWhitney water injection bottle. Did it do anything? It bubbled and that was interesting and it didn't hurt. Just nostalgic for the old days when everything was simple and there was a lot of room under the hood for putting quart jars of water in.

 

[DGXR]

Originally Posted by billt460
Is there a down side to this procedure? Can you damage anything like electronic sensors in these modern vehicles? I've heard of water injection used as a way to increase power in older military aircraft. But for some reason spraying water into a running automobile engine doesn't sound like something most should be doing.

If someone is doing this on a modern FI engine, they should disconnect the air cleaner from the TB/intake and spray the water directly into the TB. Since this will remove the MAF sensor (and perhaps IAT) from the system, it might set a code. But as long as they aren't spraying fire hose quantities of water, no damage will occur and any codes will reset after the air cleaner system is reassembled.
None of this should be necessary in a healthy engine that has been maintained. But the OP had an oil burning condition that made this cleaning a good idea.

 

[Oily_Thing]

I used to use ATF to clean out carbon. Just slowly pour a quart of ATF down the carburetor while revving the engine to keep from stalling. It made a little smoke doing that.

 

[slo town]

I would never do that on a car worth more than $1000. Check that. I'd never do that to any car.

Scott

 

[wander2039]

Originally Posted by billt460
Is there a down side to this procedure? Can you damage anything like electronic sensors in these modern vehicles? I've heard of water injection used as a way to increase power in older military aircraft. But for some reason spraying water into a running automobile engine doesn't sound like something most should be doing.


I found a vacuum line that goes straight to the intake manifold. I wouldn't spray it in like a carb. I've used it on several EFI engines with no issues. The downside is doing too much you'll be buying a engine lol

 

[Kruse]

Quite a few years ago, I read on some forum where a Cadillac tech tried to do a decarbonization on a Northstar engine and filled up the intake runners with water because he was doing it at idle instead of high-revving it during the process.
As soon as he revved it up, the engine gulped a bunch of water and did a hydro-lock on a customer's engine. The dealership paid for a new one.

 

[billt460]

Originally Posted by Eric Smith
The downside is doing too much you'll be buying a engine lol

That's the potential problem I was referring to. How do you know when you choose to walk this mechanical tightrope, exactly when you have crossed the boundary into, "too much"? Sounds like an expensive gamble to me, regardless of how it's done.

 

[meep]

I've done it many a time with no adverse effects, but the improvements minor. On really old/neglected vehicles I skip water and drizzle seafoam for a while more and more until it bogs and quits. Let it soak, then crank it up and drive it. Problem: on the worst vehicles, the CC carbon soaks up the seafoam, and after restarting, the dark cloud will absolutely engulf.... in personal experience, I had a bad experience with this - early one morning 1/4 mile of my neighborhood and the next 1/4 mile to the grocery, at which case I shut down and pulled over because it clouded up the entire route I'd taken.. Not a responsible citizen or kind neighbor..... I waited until there was wind, then re-started and idled it until it dissipated and I could come home. The engine ran remarkably better after.

 

[BMWTurboDzl]

Originally Posted by billt460
Is there a down side to this procedure? Can you damage anything like electronic sensors in these modern vehicles? I've heard of water injection used as a way to increase power in older military aircraft. But for some reason spraying water into a running automobile engine doesn't sound like something most should be doing.



It's more of a misting than spray and acts like a steam cleaner. Water does reduce combustion temps which can increase power. The current BMW M4 GTS uses water injection. IIRC this is the only OE water injection application produced for a modern car.

Owners of tuned euro cars will often install an aftermarket methanol injection system. I don't think they run pure methanol but it contains some percentage of water.

 

[FCD]

Originally Posted by Kira
How many miles/kms are on your Capri?

The engine isn't the original one but around 180k miles.
In good shape though, burns no oil at all, very little blowby, good compression and oil pressure still.

 

[Linctex]

An old windshield washer nozzle in the inlet duct right before the throttle body works perfect.

It's BEST to do it under a load - you can use the washer fluid tank and pump, too.
Just disconnect the wiper motor so the wipers don't run while you are pushing the washer button.