DIY question: W126 fuel pressure regulator
 

Hello Folks:

Finally tracked down the source of a "gas fume" smell in the cabin of my '89 560SEL: apparently the diaphragm inside the fuel pressure regulator has failed, causing gas to travel down the line (the one that looks like a vacuum line but isn't, just an atmospheric vent) into the breather hose that connects the air cleaner to the top of the valve cover.

I've looked through posts here and it seems to be a fairly straightforward parts swap (i've even got some golf tees handy!), but I wanted to know, since this is not covered in my CD-ROM shop manual (at least I can't find it!) if there are any tips or tricks to this before I get under the hood.

Any advice, experience, or stories will be most appreciated!

Thank you.

OneTwoSix

Fixed.
 

Well, replacing a fuel pressure regulator on a 560SEL is a DIY. :D

Only one trip to the auto parts store mid-way into the replacement: for a can of PB Blaster, a chemical I can now highly recommend over Liquid Wrench. One of the nuts was siezed up quite hard (it had only been sitting there on top of the engine for 14 years after being put on in Germany! haha!) and PB Blaster got it loose.

Other results: car now idles so quietly at stoplights that I can't tell the engine is running. Also, the gas fume smell is now gone.

I love pre-1995 Mercedes. :cool:

Cordially,
OneTwoSix
Current: '89 560SEL, 135K.

I would recommend and oil and filter change as fuel has be flowing into the head and thus into the oil sump. Fuel+oil means oil is to thin and contaminated.
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