I know oil threads are played out but....

So I recently (~1250 miles ago) switched to the M1 Formula M 5W-40 from LiquiMoly 5W-40 (the regular Leichtlauf stuff). I don't know why I switched. Maybe I was lured in by the factory M1 pitch. Or the "protects cats" thing since these like to use oil and these cats are ungodly expensive. Or that people have said LiquiMoly products are....average, and nothing special. Well, at 800 miles I had to add my first quart and this was consistent with the LiquiMoly. But then another 450 miles later I had to add another quart of M1. Yikes. I did check underneath again and the same wetness from the rear main is there but really no geyser of fluid. I guess it's burning it. I have seen some visible tailpipe emissions under certain circumstances. If I cold start it and shut it off before warming up, the next time I start it I tend to notice a puff. Also sometimes when I go WOT I will see a cloud behind me though it always seemed darker than oil smoke. Either way, things seem worse with the M1 than they did with the LiquiMoly 5W-40 I was using.

So more research revealed that I shall try LiquiMoly 5W-40 but the newer Molygen varietry. Amazon reviews pretty consistently suggest a marked decrease in consumption (along with a small boost in fuel economy and reduction in engine clatter). I am driving this car on a 2,000 mile road trip in 2 weeks and I cannot deal with adding a quart every 450. That's insane.

I didn't find too much on the Molygen here but I did find a few posts that seemed positive. Anyone else running it with good results? As a reminder, my 04 has about 136k on it.

FWIW, I ordered 2 5L bottles from Amazon and 5 1L bottles from Rockauto (best combined pricing, though all Rockauto was $38 cheaper than all Amazon).

 

I've put over 500k miles on this oil as a synthetic (and prior with Castrol), starting with a 500SEL, a BMW 850Ci, two BMW 750iL's, and my CLS55 AMG. I would use it in my other two cars, but they require special Shell racing oil. It's made by Petronas in Europe for Castrol, and all of my engines have done well over 200k miles without ever being apart.

I started with Mobile 1 in my CLS55, and didn't like the noises coming out of my engine. When I switched to the Castrol the entire motor became eerily quiet.

My car doesn't use any oil between 5k mile oil changes, and the oil looks almost the same coming out as it does going in.

It's also $4.00/quart.

 

Your overall experience mirrors mine. Long ago I wrote off M1 products because they made my small blocks sound bad. I got on the Castrol 0W-30 bandwagon and have used that in any engine I care about, until this one. Actually that oil is 229.5 rated but the viscosity is wrong.

Well now I'm wondering why mine uses so much oil. Do some of these just burn more than others? I thought they all guzzled oil....

Either way I will report back how my consumption changes when I get the the Molygen in there.

 

Your car is burning a lot of oil. I have put over 6,500 miles on my S55 AMG (with Liqui Moly 5W-40 Leichtlauf), and haven't had to add any oil.

Take a look at this article. I used the engine flush (two cans), then added two cans of Liqui Moly MoS2 additive, with the Liqui Moly 5W-40 Leichtlauf.

https://www.liqui-moly.com/en/us/ges...tion-1981.html

 

The oil is too thin. I'm more interested in the 40w end of things than the 0w. That's why I switched to the Castrol. It's viscosity curve is better. Depends on where you live, and how cold it gets. I've never had an issue even in 10-20F weather. Read the technical PDFs of oils if you want an education.

 

Interesting. I will say my oil seems to get dirty quickly. Maybe I should do that. Well, I am just going to try the Molygen but if I still have issues after I will try the flush. I think it's at a low point with this M1.

The funny thing is I have sort of "flushed" the engine a year ago when I accidentally added like 5+ quarts of ATF to the engine (just idled it) on top of a fresh oil change. You'd think that would have removed some stuff.

 

That's some funny sheet Kevin. I did the same thing years ago as a nuebee. Man I learned a lot since than! LOL

 

Ordered 2 bottles of the LiquiMoly flush. I'll dump that in right before I change out this M1 for some Molygen. The good news is I'll be able to report results within the next couple of weeks.

 

Yeah. I've been wrenching on cars for a full 20 years at this point. Just when you think you've learned it all or seen everything, you learn something new. Not too proud to admit that.

 

Hello, I run Molygen 5w-40 in my CLS55 and R500 with good results. I have 155k on the R500 with a M113 and it uses ~2-2.5 qts in 6k miles and the CLS55 with 77k miles uses 0.5-1qt in 6k miles. I had the same results with Mobil 1 0w-40 so I switched to LiquiMoly. I used to run Amsoil in my Porsche 944 but cost and availability made it prohibitive. I have good luck with Castrol Edge Titanium in my Jag X-type when I still had it. Also a fan of Motul but again harder to find. I now use Motul or LiquiMoly in my differentials.

FCP Euro has good prices on LiquiMoly oils and lifetime warranty too so you can turn in your used oil and filter for credit back.

 

Formula M was factory fill over a decade ago. Frankly, it is not worth the effort to track it down or pay a premium for it.

Molygen has some favorable opinions in the W204 C63 forum and is a safe product to try since it meets MB 229.5 spec.

Rowe, Ravenol and Motul also make excellent options that meet spec.

 

your rings are getting tired is what it sounds like to me. I run amsoil 5w40 in my car and have next to no oil consumption at a 5k mile intervals....maybe, maayyybbee half a quote. the PO used M1 and the car idles and runs noticeable smoother on the amsoil, 4.5 years strong and no issues.

 

I'd suspect worn valve guides and/or seals before piston rings.

 

I tend to agree, not based on experience but based on what I've read. I don't think these are known for chewing up piston rings. Soon as I have a chance I will do the flush and change to Molygen. Then by next ~Fri/Sat I will know if my consumption has changed at all. Based on what I've read from both the flush and Molygen, this should make a huge difference.

 

Another possibility could be worn valve seals.

 

I think at this age/mileage it is quite likely. The question is, how bad is it contributing and can I mitigate it short of replacing them? We'll see.

 

Did the flush. Poured 1L in hot and idled for 10 minutes then held 1000 rpm for a minute or so. Random bonus time.

Drained the oil and it was pretty black as expected. Only 1450 miles on this oil.

Poured my remaining 4 qts of M1 Formula M into the engine to flush the sump, plus a quart or two of the regular LiquiMoly I still had. 8.5L of the Molygen 5W-40. The clock starts now but the serious mileage will come at the end of next week.

 

Thought I would provide a little update.

First, this car was absolutely outstanding on the family road trip. Completely filled the trunk including the spare well with tools and stuff (that I didn't need), fluids, etc. Airmatic worked perfectly to level everything out. The car is an amazing cruiser. Just eats up the miles. Handy to have a reserve of power for those truck parades on I-81. Most tanks were between 21 and 22 mpg. A little worse than expected but with the load I was carrying I guess it's acceptable, plus I wasn't exactly cruising at 65. I did NOT air up the tires to the fully loaded specs. Just left them at around 34-35 psi cold.

Onto the oil stuff.

7/1. Made it about 447 miles and when I checked it said to add a quart (may have said 1.5) but I added 1 qt.
7/2. Another 538 miles and when I checked it wasn't fully level but it said 1.5. So I added another quart.

Clearly this is not improving. By 7/2 I had made it from RI to NC so I had a few days to decide if I wanted to take any action such as buying more oil (I brought 5 makeup quarts of the Molygen 5W-40). After some research, I decided to research the various stop leak products out there. Yes, I know. Ended up looking at AT-205 which actually gets good reviews on Amazon (and Scotty Kilmer if you can stand him). Couldn't get that quickly, though. Ended up driving to a local Advance Auto at my vacation spot and perused the shelves. Ended up picking up an 8oz bottle of Blue Devil Rear Main Sealer. I believe it is a similar formulation as the AT-205 because it pours clear and thin like AT-205 and seems to have a similar approach (something something polymers). One bottle treats 8 qts. Close enough. FWIW, the Advance lady thought that was their best product based on customer feedback and (lack of) returns. Good enough for me, as the stress of continued oil consumption was, well, consuming me.

Poured it in on 7/5. Before leaving for the first day of the return trip on 7/9, I checked the oil level (again, not level). Said to add so I added a quart at only 327 miles (and this doesn't count the 8oz of stuff I also poured in). Not looking good for a 900 mile highway drive, with only 2 makeup quarts in the trunk.

Checked the oil at every fill. Actually, I checked once in VA and it said overfilled, reduce. I checked immediately again and it said level OK. It was a pretty hot check so kind of odd.

Anyway, made it back home with no issues. And to my surprise, it has now been 1,026 miles since adding the last quart, and it still says level OK (this time level in my garage). That is a clear improvement. This also seems to support my diagnosis that some combination of valve stem seals + rear main is probably my issue (and not any kind of ring sealing). This stuff would do absolutely nothing for any ring issues. And furthermore, the flush and Molygen was supposed to help clean up dirty rings yet I had no improvement from that step alone (so my ring sealing is probably just fine).

Curious how far I'll go on this quart before it registers low. Also not sure if I'll just run this oil to 5,000 like normal or drop it earlier. Or if I should add more stuff to the next change or leave it out and see what happens. Yes, I know my car needs a repair but I don't currently have a lift and I'm not pulling the trans on my garage floor.