97 E420- switching to Mobil1 synthetic, but use engine flush + cleaner? - PeachParts Mercedes-Benz Forum

ProV1 · #1 10-04-2006, 10:59 AM

Car - 97 E420 106,000 miles

Past owner used mineral oil for 9 years, but I'm switching to Mobil1. I must assume there is a some sludge & buildup, and also switching to Mobil1 w/ high detergent level will break things loose. Therefore is it advisable to use a engine flush and/or engine cleaner (www.auto-Rx.com?) before switching to Mobil1? I will also use a bottle of Techron fuel cleaner.

Car gave P0172 (too rich bank#1) code a few months ago, and the spark plugs and connectors were replaced. However the car has an unstable idle and rpm drops periodically. I also have the dreaded ticking noise. I want to start w/ most simple solutions first before moving on to MAF, injectors, coil packs etc.

Thanks for help.

sokoloff · #2 10-05-2006, 08:01 AM

I would never put that flush product in my car. The Mobil 1 will remove sludge, etc. slowly on its own. If you use Techron, I'd add it before doing the oil change.

Len

lkchris · #3 10-05-2006, 09:59 AM

Best to get your Techron one tank at a time by using Chevron gas.

Or, any Top Tier gas.

Belief in liquid solutions for auto maintenance is something best left behind.

page62 · #4 10-05-2006, 04:16 PM

I agree with sokoloff and lkchris. Change the oil and filter, put a bottle of Techron in the gas tank, and be happy!

Kebowers · #5 10-06-2006, 02:21 PM

If you suspect internal varnish or gum in the engine, look inside the valve cover. If should be clean in there with no brown or yellow or black deposits. If any, I strongly recomend using BG-44 engine cleaner to safely remove the crap. Use it in a good petroleum oil--the 'old fashioned' oil actually will suspend and dissolve lots more crud than the synthetics will. After runnig the BG-44 no more than 2000 miles change oil and filter again, this time using 1 pint of Marvey Mystery Oil in the fill. This will gently soften and remove clear laquer/varnish without causing it to crack and flake off-potentially plugging oil passages. M-1 and other synthetics have been hyped so much that one can easily believe you really never have to change it, in fact just put the container NEXT to the engine and it works magic. Tain't necessarily so as thay say. Premium conventional oil with 5000 mile changes (highway only) or 3000 miles city/suburban short trip use, will keep your engine just as clean or cleaner, will provide just as much wear and corrosion protection, and will remove more harmful dirt ingestion than synthetic oil used for the 10-15K drain intervals touted.

Fuel AND oils, and air filters are much better than 5 years ago at keeping the entire engine clean. Especially if you use 'clean-up' or Teir 1 quality gasolines.
Every 'real world' endurance test has shown conventional oils more economical and equal or better in engine wear protection overall than any synthetic. THe ultra-long drail intervals do not work except under the strict 'long trip moderate or lower load , clean air, high quality fuel regimen.

Will_w202 · #6 10-07-2006, 11:18 AM

I switched to Mobil 1 at 75k on my M111, and developed a very small leak 1k after that. Luckily she was still under Starmark, and they replaced all my seals including head gasket (I'll buy CPO again for sure). That said, the leak was small, but you just never know. The stuff flows much better than dino oil. Just be prepared in case.

As for flushing, some other members have a great solution - a diesel oil, preferably either Delo 400 or Delvac 1, 5w40. The stuff is designed for HD OTR use, and it is like Mobil 1 on steroids as far as detergents. I would run it maybe 3k and change it. I ran Delvac 1 in my old Jetta TDI for the first time after 30k, and at 5k, I had 8% soot based on oil analysis. That's a LOT. That stuff will SCOUR your engine, safely

Hatterasguy · #7 10-07-2006, 08:24 PM

Your not kidding, you should see the inside of my 603 diesel after 20k miles on Delvac 1. Its like new!

That stuff cleans for sure!

Gilly · #8 10-07-2006, 08:43 PM

I agree with the "no-flush" crowd, just switch it and I'm sure you'll be fine.
Better watch out that your dreaded ticking noise isn't caused by the dreaded "broken oil tube"
Gilly