MotorVac Question

[BENZ-LGB]

My friend's 1989 420SEL has developed a pinging problem. His mechanic has indicated that he needs a "head job" to clean out the combustion chambers and valves from all carbon deposits. I mentioned a MotorVac procedure as a less costly, and perhaps as effective, alternative.

His mechanic told him that MotorVac is nothing more than a witches' brew and that he might as well throw the money he would spend on a MV away in the trash. He also said that there is a danger that with MV a chunk of carbon could be dislodged and start rattlign around the engine, causing more damage.

I told him that I would submit the issue to you guys here and get your "vote."

I also did a thread-check and I will give him any current information on the MV procedure. I would just like to get more updated info to pass along to my firend.

Also, whatever happened to the debate on the Delco fuel system cleaner (I think it is called X66-P). I remember that about a year ago, there was a whole long thread on the pros and cons of this product.

Has anyone used this product recently? Good? Bad? Indifferent?

Thanks y'all

[JCE]

Stevebfl though highly of it for some situations - MotorVac? . The search for Motorvac turned up the threads on x66p and related compounds (looong discussions).

[pmizell]

I used "GM top engine cleaner" (same or similar to X66?) on my 300E, and if the billowing smoke after use was any indication of the product loosening and burning off carbon, it worked very well.

However, a few thousand miles later I pulled my head for a valve job and found a good amount of loose carbon flakes in every cylinder.

I suggest using the X66, or GM top engine cleaner ($6 from any GM parts dept) and afterward, vacuuming out the remaining carbon from each cylinder bore thru the spark plug hole.

If used properly (follow instructions on can to a T), these "top end" cleaner products work very effectively.

Good luck

~Paul

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'91 300E, 213K miles