Date registered: Oct 2005
Vehicle: '04 G55 '80 280GE '99 S420 '98 E320 2011 E350 2016 GLA250
Location: South Texas
Mentioned: 8 Post(s)
Quoted: 154 Post(s)
Photo DIY- M119 Engine Compression Check
Since it was time for me to change the Spark Plugs, I normally like to do a Compression Check, just to keep a record of the internal "Health" of my engines...
The write-up is from the WIS, which I was Shocked to see there was NO bypassing of any of the fuel relays, like most tutorials. Since my engine had no rear CPS in the location shown in the WIS, I went to the front sensors and unplugged them to keep the engine electrical system off-line.
Please note, DON'T push the Gas Pedal to Full Throttle like most Compression checks.. and place transmission in Neutral while cranking using the CAR KEY, rather than the Hand Starter like my other vehicles....
I hope this encourages someone to also keep up on their car's "Wellness" Check-Up...
Please note, this is for the '99 S420 M119.981 Engine. Of course, at the end, it is the "re-install in reverse order" mumbo-jumbo. Keep the Coil Spring orientation correct.