Has anyone tried Motor Vac?

mattski · #1 08-14-2002, 01:22 PM

Has anyone tried to clean out the combustion chambers with a system called Motor Vac? I have had it done on my Ford Aerostar and my mechanic has recommended it for the SVX as well. He says that one of his other customers has noticed a significant improvement in performance and economy. It is intended to clean out the fuel injectors and carbon deposits on the valves and pistons.

Ovidiu STAN · #2 08-16-2002, 12:16 PM

Did you see any improvements on your van performance?

How much it was?

Thanks

LarryIII · #3 08-16-2002, 12:31 PM

Mattski,

I never heard of it.

mattski · #4 08-16-2002, 12:37 PM

I have had the procedure done as part of periodic tune ups so it is impossible to tell if the improved performance was due to Motor Vac or new plugs, clean throttle body, etc.

I have read the recent posts regarding the hesitation prior to warm up and I have to say that my 97 with 55k does not suffer from this issue. I was wondering if a good fuel and combustion chamber cleaning would help in this case.

svx_commuter · #5 08-19-2002, 11:35 AM

I have used it on all my high mileage cars and the SVX is one of these. I did not notice any performance change or MPG improvement. It did however fix the surge I had with idle speed when the car is first started.

I recently had the SVX engine apart and saw what the VAC did. There was still carbon in the combustion chamber. I thought it should have been gone form the pictures I had seen. I am thinking now that maybe the Vac works better on cars with the injector in the combustion chamber. The SVX injects into the intake header before the intake valves. How is the injector going to get dirty in that position? Unless you got leaking intake valves.

I have not tried this yet but an older mechanic says carbon can be removed by spraying a mist of water into the air intake. I may disconnect the air hose from the filter box and give that a try.

mattski · #6 08-19-2002, 12:00 PM

Is Rick Allen your mechanic with the Motor Vac?

Beav · #7 08-19-2002, 05:31 PM

All things are relative. Modern cars with electronic injection and igniton don't pile up clods of carbon as they used to in the days of carburetors. We used to see valves that no longer had a 'T' shape to them, they had collected enough carbon to look like a 'Y'. The misting of water into the manifold thereby won't produce the same results. A little carbon here and there in the chamber is o.k., it's usually more like a heavy film at worst. The main objective of the motorvac and similar systems is to clean the injection system, intake runners and throttle body.

Most of the crud in the throttle body and intake manifold is a result of the introduction of crankcase vapors from the pcv system. In days past the intake manifolds were heated by water flowing through them or exhaust gas crossing below the carb, heat from the engine oil splashing on the bottom of them or any combination of the above. The oil vapors weren't much problem then but now with 'cold' manifolds the vapors condense and crud things up a bit. The carbon in carbureted engines was a result of poorly metered fuel incompletely burning and leaving deposits behind.

BTW, while there's been some rumors of new engines coming out with direct injection, the only engines with that feature to date (to my knowledge, for whatever that's worth) are diesels. All current production gas engines that I know of are port or throttle body injected.

Ron Mummert · #8 08-19-2002, 07:20 PM

I have not tried this yet but an older mechanic says carbon can be removed by spraying a mist of water into the air intake. I may disconnect the air hose from the filter box and give that a try. [/B][/QUOTE]

Isn't this procedure known as a "Mexican tune-up"?
Not that there's anything wrong with it.

Don Ron.

svx_commuter · #9 08-20-2002, 05:52 AM

HI Matt,

Yes. Rick Allen is the only local mechanic with MotorVac that I have found.

Quote:

Originally posted by mattski
Is Rick Allen your mechanic with the Motor Vac?

svx_commuter · #10 08-20-2002, 06:00 AM

Quote:

Originally posted by Beav
A little carbon here and there in the chamber is o.k., it's usually more like a heavy film at worst.

BTW, while there's been some rumors of new engines coming out with direct injection, the only engines with that feature to date (to my knowledge, for whatever that's worth) are diesels. All current production gas engines that I know of are port or throttle body injected.

So this amount of carbon is normal? The MotorVac was done about 15k miles before this picture.
http://www.subaru-svx.net/photos/fil...muter/3713.JPG

Also thanks for the facts on where the injectors are located. I thought the MotorVac sales pictures showed direct injection.

So, what is the SVX injection called?