Monique

Capacity is 72 total.

Sorry about "motorvac".. don't know

GabiOsz

Good, i think i have it sussed now with the dosage, I have used STP fuel system cleaner, can anyone recommend any other decent brand in the UK that actually works?

GabiOsz

Does anone have any idea if there is a UK company offering the MotorVac Carbon Cleaning service?

Also can anyone recommend any carbon removing fuel addatives that would be available in the UK that will actually work?

User 4221

If you can find it in the UK, Google BG44K. I have used it on many motorcycles and my old 928 with great success. It will do clear up your fuel system and work on the carbon.

HTH,
Scott

1999Porsche911

I regularly (1 time a year) pour a ahlf a quart of of tranny fluid in my cars to clean and lube the upper part of the engine. I have done so since my first car 30 years ago. It does help to remove any carbon buildup in the upper chambers ofthe engine.

In a closed throttle body setup, simply disconnect a vaccum hose and stick in in the botle of tranny fluid when the engine is running. Do it outside because it will smoke like hell. Once the amount you want in the engine is sucked out of the bottle, turn the engine off and let sit for 5 - 10 minutes. Then drive the car for a little while until the smoke is gone.

I doubt that this procedure will do what is necessary for heavy carbon build up, but if done regularly, there wil be no heavy carbon to remove.

JasonAndreas

Do you temporarily pull the cats when your running tranny fluid through the motor?

1999Porsche911

Noipe. No need too.

Steve Weiner-Rennsport Systems

Hi Gabi:

I'm guessing that you have a case of exessive carbon buildup caused by the ubiquitous Porsche valve guide problem. This does two things, raises the mechanical compression ratio which in turn requires higher octane fuels, and leaves small glowing bits of carbon which trigger detonation.

The Motorvac process is pretty effective although I do not know if anyone in the UK has one.

With this treatment, your car's fuel injection is directly connected to a self-contained fuel delivery system that sends a concentrated solvent (with no harm to cats) into the engine for 20 minutes or so at idle. Then, the car's FI is reconnected and then the car is driven "briskly" for 5 miles or so.

This loosens and removes a lot of deposits on the valves, injector tips, and piston crowns. We always follow this treatment with an oil change and if the oxy-sensor(s) is/are old, they get replaced as well.

If that doesn't do the trick, then the only other real cure is to remove the engine, pull the heads and install new (non-OEM) valve guides with factory Viton seals to eliminate the root cause of the carbon buildups.

I would suggest that you contact MotorVac at http://www.motorvac.com and see if they have sold one of their machines to a UK shop or dealer. LubroMoly (Germany) also makes a comparable machine and perhaps someone in the UK has ones of those, as well.

If you were here, I'd have you all taken care of,....

JasonAndreas

Have you ever looked at a cross-section of the ceramic insert inside a catalytic converter? Even at 600F, I would think blown-off carbon from your cylinder heads, valves, etc. is not going to burn 100% and there is absolutely no way that even the tiniest chunk is going to make it completely through your catalytic converter?

GabiOsz

Thanks for all the advice, it sounds like I am way past being able to clean things up with a fuel additive. I hope I don't need to get work done on the engine, that sounds expensive, how much would an engine job like this cost me? Also do you know what people generally charge for a MotorVac service?

GabiOsz

Sorry to reserect an old thread.

I have been reading a little on the subject of dieseling and have found the 944 board blaming a leaky/clogged fuel injector or bad ignition barrel. It seems strange that a fuel injected engine should find the fuel to diesel when the ignition is shut off unless an injector/the DME is letting fuel into a cylinder, unless there is a leaky injector or the DME is still pumping fuel, any thoughts on this? Is there a way to check this myself?

Carrera Mike

Gabi, just curious, how much KM/Miles do you have on the car? Tnx

GabiOsz

I have 71.5k miles on the car now, but the problem has been there since i bought it with 55k miles.

993inNC

I used to use the water in the cylinder thing back when I rode sportbikes (can't recall how I got it in there though). But if you can find "SeaFoam" its a chemical decarbon agent, it work pretty well. I use it in my tank strait, just as I am on reserve fuel (runs a more concentrated mix of the chem.) I have also used it by rag on a Vette I used to own, works wonders. If you can find the lowest point of intake and get the stuff in that way either at idle or even off, that'll be the best way to use it for really sevre build up. I you have time to let it sit and soak, even better, but if you do it while running make sure you're outside, it blows a nasty yellow cloud!

Steve Weiner-Rennsport Systems

Hi Gabi:

IMHO, you need some professional assistance on this since this really transcends a DIY-type analysis and solution.

Fuel injectors do go bad and either will not fire a proper pattern or they will leak. It takes some very specialized equipement and knowledge to test, clean and calibrate these things. Sometimes, its replacement time for ones that do not clean up.

The MotorVac or LubroMoly process is FAR better than simply connecting a vacuum port to a can of some solvent in the quest to clean the valves and piston crowns. Connecting the fuel injection system to an alternate fuel source like these machines cleans everything that the fuel touches. Using the wrong chemical can trash oxysensors and cats so Caveat Emptor.

There just has to be someone in the UK with a device like these,....