Hi all, I was thinking about having my 89 v12 carbon cleaned. No particular reason to do it, just seems like a good idea. Wondered if anyone else has had this done? Any positive or negative reactions? Many thanks

 

What is carbon cleaning?

Cheers
DD

 

Hi Doug,
It's where they run the engine on a chemical that removes built up carbon deposits.

 

Waste of petrol money Brinny! The cylinders will not be coked up.

 

Good enough for me Greg.

 

Good decision! A blast across the Yorshire moors will be far better for the engine and far more fun!

 

Italian tune up!

Italian Tune Up Explained - Removing Harmful Carbon Deposits (roadandtrack.com)

 

Among other reasons, one MUST allow any engine to "Kiss the Red Line" once in a while (like, Every Shift after reaching operating temperature until the speed gets dangerous) or they think ya don't love 'em!
If you've never done that, you'll be amazed just now much Pure, Unadulterated Fun it can be!

 

Ahhh. OK

Cleaning out the carbon. Got it !

By "carbon cleaning" I thought you meant cleaning something with carbon.

I'm with the others. Save your money. Keep your combustion chambers clean for free with a few full throttle blasts to 5500-6000 RPM. Look at your exhaust in the review mirror. You'll know when the carbon is gone.

Depending on your driving habits and conditions once a month should do the trick. I do about 95% city driving so mine needs the treatment more often. Mind you, I derive no pleasure at all from doing so. A miserable task but, hey, it must be done for the well being of the engine. :-)

Cheers
DD

 

This will shock you and I’m sure to get heat about it . But when you do your carbon cleaning. Fill your tank with 10% ethanol.
Alcohol, the right kind of alcohol. Ethanol not methanol. Really softens up the carbon deposits that our fuel injection system puts on the back of the intake valve.
As every Jaguar owner should know our EFI is batch injected. That is 4 injectors at a time open up and squirt gasoline in. it then leaves the camshaft to decide which valve open and when .
While that fuel is aimed at the back side of the intake valve it’s relatively cool. And hits that valve. Some is left behind as a carbon deposit.
As I said alcohol dissolves carbon. Oh and cleans deposits on the combustion chamber as well ( plus the spark plug)
Now some misinformed people object to alcohol. They aren’t sure why but they’ve heard stories.
Race cars love alcohol. Indy 500, 100% ethanol. NASCAR 15% ethanol Drag Racing puts cars with ethanol in faster classes because it makes more power same with land speed record setting. Alcohol puts you in faster classes.
Now about here some one who knows a little will tell you alcohol has less energy than gasoline. ( he’s right it does have less energy than gasoline. But gasoline had less energy than diesel fuel.)
The reason Alcohol makes more power is it has extra oxygen to burn more of the fuel.
Just remember Ethanol is in beer wine and scotch. So it’s good for you and your car. Methanol on the other hand is real bad for you. You drink it, you die! It’s also bad for your car. It attacks rubber and aluminum etc.
So those who think alcohol is bad confuse one with the other

 

Just to add a slightly different perspective and some personal experience:

There seem to be 2 primary treatments that are aimed at carbon deposit cleaning.

The first uses hydrogen injected with the primary aim of cleaning carbon deposits from the inlet tract, valves and combustion chambers.

The second connects the car to a specialised fuel supply which is used to clean injectors, inlet tract, right through to cats and lambda sensors.

I trialled out the second type of treatment on my AJ16 XJS using the "Terraclean" technology some years ago. https://www.terraclean.co.uk I believe they also have US representation?

As the treatment started, the engine started to run a bit rough with noticeable exhaust smoke as elements were no doubt being cleaned out from various areas. The engine then started to run much much smoother and the exhaust smoke disappeared. After the treatment my CO figure had reduced to Zero and my HC figure had come right down to a very low figure. The idele was smoother and the pickup from idle revs was cleaner, presumably from the injector cleaning.

A treatment such as this cleans a number of areas not just the valves and combustion chambers. I was very happy with the results and I'd certainly consider having it done again when the car has done a few more miles.

As regards the hydrogen cleaning approach, I don't have experience of that. But a friend of mine fitted a water / meths kit to his x350 XJR. We then put a scope down his engine 10,000 miles later and the cleanliness of the valves and piston crowns was quite incredible. The water / meths had cleaned every bit of carbon buildup. It has seriously made me think about fitting water injection to the XJS!

Paul