The thread on April 22 about 960 valves included some discussion about injecting water via a vacuum line on the throttle body to clean carbon deposits. Sped mentioned a technique of routing the windshield washer hose into the throttle body to inject at highway speeds.

My question is: If the steam is blowing through the exhaust during this technique, is there a possibliity of damaging the Oxygen sensor? My mechanic once mentioned this possibility when a head gasket blows and antifreeze goes thru. Would this also apply to plain water?

Robert

I am sure that it will not harm your O 2 sensor. As for the MG anything built by the brits warrants special care, they are not volvos!

did the B have a cast iron cylinder head???

i would certainly be carefull about introducing too much water into anything...3 possible causes of damage i can see..

1. rapid cooling of localised spots in the manaflold/head leading to cracking/stress in the head/manafold/valve

2. steam formed in cylinder causing excess presure in the cylinder...possibly leading to (least nasty) steam being forced into the crank case removing oil fro mthe ring lands, prsurizing the crank and contminating the oil

3. OK this is excesive.but possible hydro-locking of the cylinder causing complete engine failure (eg snapped con-rod)

basically a procedure i would approach with some (considerable) care..

ok and last but not least...with a turbo im not sure what allthat steam hitting the turbo blades would do...

I think the idea is to introduce the water downstream of the turbo.

Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

yep...but its still steam in the piston, then exits via the exhaust porrt and hits the turbo blades in the exhaust...

True, but a significant amount of steam is normally created during combustion anyway. Add to that the acids and other nasty stuff in exhaust, and I doubt a little more water/steam is going to hurt anything. But I'm just guessing, since I have no first-hand experience with the procedure.




Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

I tried this on an MGB with disastrous results. The goal wasn't valve cleaning, but to get some of the carbon out of the chambers and stop the incessant pinging under load. Technique involved going down the highway at 3000RPM with the water being sucked into a manifold fitting from a jar in the cockpit via a long rubber hose with a 1mm flow restrictor in it. Engine sure ran roughly every time I unpinched that hose...After a few miles I observed a lot of blue smoke from the exhaust. Engine had not done this before. (well, it leaked - after all, it's British, but not an oil burner). Compression is low on one cyl and I believe I could have cracked a piston or broken a ring. Anyhow, above a certain RPM, it now blows a big blue cloud. Proceed with caution. Cleaning valves is probably best done via a commercial fuel system cleaner like Chevron's Techron.
--
Bob (81-244GL B21F, 83-244DL B23F, 94-940Sedan B230F)

Water (a normal byproduct of combustion) will not affect your oxygen sensor. Glycol will.