tj90

Has anyone done it on their 993? Never done it on any vehicle, gonna try on my other vehicle to see how well it works. I dont have driveability problems but wonder if things can be better - plus, Im bored....

beentherebaby

It's effective at causing rust on internal engine parts.

vincer77

Doesn't sound sound.

Terry Adams

I did this on 60's cars, where you can impress friends holding a white cloth over the exhaust.

If you value your 993 or any other modern car, do not do this.

johnsjmc

It,s an old fashioned technique, left over from the model T.. If you ever dismantle a water cooled engine with a bad head gasket or a cracked head it is very obvious which cylinder was affected .The cylinder which had water going through it will have the carbon steam cleaned from the piston and combustion chamber and be shiny and clean. Other than corrosion from the leftover water I would also be concerned about the risk of thermal shock and worse could be hydraulic lock. Engines have been ruined by ingesting water through the intake in a bad rainstorm,why risk it. There are decarbonizing tune up sprays which would be a better choice if you have a drivability or emmisions problem. IMHO

race911

What carbon problem exists on these engines? Worst I'd ever see was in the flame quash area of the funny shaped 2.7 and 3.0 CIS engines. Can't say I remember seeing much on the oh-so-rich running MFI 2.0-2.4L engines, but someone who worked in that era could correct me.

johnsjmc

Carbon in the "rich" 2.0,2.2,2.4 engines was mostly a plug fouling issue.Worn valve guides would leave carbon deposits on the back of a valve but thats common in any oil burner. Little carbon combustion chamber deposits that I remember. The original question was re a 993. With 11.3 CR there is less room in the chamber, compared to earlier engines, to fill with water without the risk of a hydro lock and bent rod or worse.

geolab

https://rennlist.com/forums/993-foru...ight=HYDROLOCK

tj90

George: I read your post and it is very interesting. You were successful using water but then at the end you say dont do it. I guess you figured too much risk for the reward. I figure this is an option if suffering problems but not worth it if you just want to tinker.

geolab

is it worth maybe killing a catalytic conv? no
throttle response was as good after a fuel can of injector cleaner.

cgfen

don't worry about the rain, let's go for a ride, that will cure boredom

LOL !

2Many Cars

I've heard of this being done on very early MGs and always thought of it as a last ditch attempt to avoid pulling the head for what in the era was sometimes known as a "decoke". Back when most cars ran on very fat mixtures and wide machine tolerances produced a fair amount of oil blowby this was a periodic necessity. A well maintained engine today shouldn't need this.

johnsjmc

Hydrolock would still be my biggest fear. I had a 327 Chev engine in a 1964 Corvette I owned years ago. Comp ratio was 11:1 I ended up with a bent rod about 1000 mi after a careful rebuild. We traced the cause to a leaky float in the carb,it allowed fuel to dribble into the intake when stopped. The small high comp. combustion chamber was partly filled with liquid on one cyl. which had an open intake valve. When started there was enough to stop the piston when rising and bend a con rod.