Mobil 1 0W40 in my older Mercedes engine

[190E26FTW]

I used this oil based on everyone's recommendation here as previously my car has ran for 158,883 miles using conventional Castrol GTX 20W50 oil most of its life.

I had to rebuild my head gasket after it blew up when I added Royal Purple Purple Ice coolant additive to my cooling system. It did not mix very well with Mercedes coolant and actually turned into a thick greasy jello. I tried flushing it 60 times but could not get it out. It blew my Behr radiator 2 times and 1 heater core. Ended up costing me a ton of money. Lesson learned. RP would not help me with the matter and even blamed me for using their product wrong. Anyways I diverge.

So after the rebuild I decided to use Mobil 1 0W40 since everyone has been giving such good reviews of it. It made my car very noisy and the gas mileage went down. The best I could do was 17 or 18 mpg each tank. My car normally gets 21-26 depending on highway driving. Its weird for me to get such bad gas mileage. So today after only 1500 miles on the 0W40 I went back to the thicker stuff- M1 15W50. Hopefully this will cure some of the ills my little car has. When I pulled the magnetic oil drain plug out there was a good size black ball of metal stuck to it. I wonder if the thin oil caused the older engine some wear? It has to be iron because the aluminum in the head will not stick to magnets.

Anyone else have issues using thinner oil in an older Mercedes inline 6 engine? My car is a 1993 190E 2.6. Please feel free to discuss.

 

[d00df00d]

to BITOG!

Question: Why are you blaming the oil and not the rebuild for the issues you are having?

It's not unusual for a freshly rebuilt engine not to run at its best until it is broken in. It's entirely possible that fuel economy will come up short and noise will be slightly higher, and it's a certainty that the engine will shed lots of wear metals for the first several thousand miles of its (new) life.

If I were you, I would petition the moderators to change the title of your thread. There is no reason to blame the oil for the performance of a freshly rebuilt engine. Break it in according to the rebuilder's instructions, and THEN switch to whatever oil you want and see how it runs.

Who rebuilt your engine? Did they have break-in instructions? Did you follow them?

 

[unDummy]

Did you verify the thick greasy jello by mixing in a separate container? Or did the RP do some cleaning?

After the head gasket replacement, you should perform a couple short OCIs to remove any coolant contamination from the oiling system.

If you want to find out what happened, you run the 0w40 a couple times and take samples for a UOAs. Then you run the 15w50 and do the same. Compare the results.

60x flushing? That I won't believe.

 

[SuperDave456]

You think the material collected by the magnet could be left overs since you had the head gasket replaced?

Have you ever run anything besides 50 weight oil in your Mercedes?

 

[190E26FTW]

Well I still do have 2 cases of 0w40 left. The 60 times flushing was more like drain and fill and drain and fill kind of thing. Sometimes I would add in Super flush or Mercedes citric acid powder.

Oh I rebuilt my engine with a friend. Had the head cleaned up at a machine shop. It was a pain in the rear to get the coolant mixed with oil out. Probably still some gunk inside. I will do short oil changes then and hopefully clear up some of these ills. Not sure if winter fuel has anything to do with it too. I usually use Chevron 91 or Shell 91. Thanks for your input guys. * I already changed the title. I didnt mean to come out as attacking the oil as its great for newer cars but not so good for older ones like mine where the specs and tolerances are a lot looser now after 160,000 miles and being 18 yrs old. The car ran really rough on the thin oil and shook too. My engine mounts are brand new factory ones.

Super Dave I have always just run Castrol GTX 20W50 in my engine. First time using M1.Before I closed up the engine I stuck a neodymium magnet down in the holes to pull pieces of the broken head gasket out. It could be residual left over.

 

[190E26FTW]

Thanks for the welcome D00df00d!

Are there other companies beside Blackstone that does the oil analysis?

 

[d00df00d]

Tons. What do you want to learn from doing the oil analysis?

 

[440Magnum]

I'm running a fill of M1 0w40 in my 1966 Mopar 440 right now (rebuilt engine, has about 20k miles on it, prone to piston slap due to material, design, and fit of pistons I chose- live and learn). So far its working extremely well- a UOA will tell for sure, but the "ear test" says the piston slap is less than it was with RT6.

 

[CATERHAM]

If you engine is not badly worn; i.e., you're getting normally oil pressure, M1 0W-40 would be an ideal oil for your 190E.

 

[Astro14]

Mercedes mechanics will tell you not to mix anything with Mercedes coolant - for exactly the reason you discovered...Mercedes coolant cost me $16/gal for straight coolant last time I bought some...not much more than regular coolant.

Not sure why you've been running 20W50 GTX...that vintage 'Benz allowed a range of viscosities, but 20W50 is pretty thick in cold weather. I've been running Rotella T6 5W40 in my '92. Used to run 15W40 Rotella in my '81 240D in the summer and 10W30 in the winter. That 15W50 is pretty thick for a 'Vegas winter as well...

I don't think the oil has anything to do with the power loss and poor mileage. Coincidence (two things at the same time) is not causality (one caused the other). It is far, far more likely that you have a leftover problem from over heating or from the rebuild: burnt valve, warped head, poor compression, timing off (including valve timing, which will manifest itself as low compression)...since the description was really of a head replacement, not a full rebuild on the motor...you may have a bottom end problem from the overheating as well...

The 0W40 is a great choice for your car...I use it in 2 of mine...I would recommend that you check compression and timing before blaming the oil...

 

[190E26FTW]

Ok thanks guys. I will look into having the compression test done on my car. I think it should be ~180 PSI across each cylinder for a normal running car.

The winters arent too harsh in Las Vegas. Except this year where it snowed 6 inches outside my house! Crazy! But the last 6 years its been high 30s usually. So the 20W50 was no problem.

I learned my lesson- dont mix nothing with Mercedes coolant. Man if you got it for $16 bucks a jug then you got a deal. I buy them from the stealer for $25 a jug.

The head was fine. No warpage. No burnt valves. Valve guides are good and valve stem seals are the new polyurethane kind. No leaks whatsoever in the head. It was machined to make sure it was flat. That was it after the pressure test. The bottom end of the block was a mess with pieces of the head gasket mixed in with yellow gunk and motor oil. I am still getting remnants of the gunk coming out. I dont think I can truly get rid of the grease in there. Had to finally put coolant in the car because it got so cold outside. I was running water the whole time.

 

[Silk]

Headgasket rot is very common with these engines,it happens as they get older no matter what coolant you use.I did the headgasket on my 1994 220C last year,and did a 6 cyl 1994 last year too.Both engines were perfect inside,both at over 250,000km,mine was at 275,000km.My engine has been run on 10/30 or 10/40 most of it's life,I'm using Fuchs 15/40 HDEO at the moment because we use it at work.

 

[Oldwolf]

Well, I am sorry and surprised that Mobil 1 0W40 is giving you problems because it is approved for you engine by MB. Also, your coolant problems odd, RP and the what I use, Water Wetter, shouldn't be an issue at all. I use Zerex G05 coolant, also MB approved, $10 at NAPA, with mine.

Let us know how the 15W50 works for you.

 

[d00df00d]

There has been absolutely zero evidence presented that the oil had anything to do with what the OP is reporting.

 

[190E26FTW]

Filled up with 15W50 Mobil 1. The engine is running much smoother now. Im sure 0W40 is a great oil for the newer cars. Yeah Mobil 1 site lists that as the recommended oil for my car so thats why I tried it. It is too early to tell with the thicker oil so I will have to drive more and report back.

I have another friend with a 1989 190E 2.6 and 89,000 miles on the odo. He started using 15W50 last Dec and noticed that the cleaning action of the oil is causing more leaks in his car. But he likes the way it feels so will keep using it. Mine has no leaks right now so I will have to see how it is after some more break in. I changed my seals so I should be good. These cars usually leak from head gaskets due to age and the timing chain cover area.

OldWolf wow that is cheap $10 at Napa! They sell it for more at least when I checked the last time I was in California. $19 for ZEREX G05

 

[Santo Fontana]

so switching from 0w40 to 15w50 fixed the problem?

how long have you had the car?

 

[190E26FTW]

Had the car its whole life. Yeah I am getting better fuel mileage now. Half a tank of gas would only take me 92 miles on OW40 and 153 miles now on a half of tank of gas with 15W50. I only use Chevron 91 octane gas. I barely hit 200 miles on a tank of gas with Ow40 and now I am getting 270 miles before my light comes on. This is mixed city and highway driving.

Weird huh?

 

[virginoil]

Hi

What you have posted has been experienced and reported before by another one or two BITOG members where thicker oil provided better mpg that the thinner grade.

IM0 based on what you have said I would not continue use the M1 0w40 definitely go back to the thicker grade even if its a semi syntetic.

Don't get sucked in by the thin is best.

Read and reasearch as much as you can and do whats best for your vehicle, some cars seem to just like certain oils or grades.

I hope the advanced search facility is fixed so you get to the see the list of threads instead of the every post within a thread. Makes filtering of the easier.

 

[Oldwolf]

Originally Posted By: 190E26FTW
Had the car its whole life. Yeah I am getting better fuel mileage now. Half a tank of gas would only take me 92 miles on OW40 and 153 miles now on a half of tank of gas with 15W50. I only use Chevron 91 octane gas. I barely hit 200 miles on a tank of gas with Ow40 and now I am getting 270 miles before my light comes on. This is mixed city and highway driving.

Weird huh?


93 miles is only 10mpg! What is wrong with your car?

 

[190E26FTW]

Originally Posted By: Oldwolf
Originally Posted By: 190E26FTW
Had the car its whole life. Yeah I am getting better fuel mileage now. Half a tank of gas would only take me 92 miles on OW40 and 153 miles now on a half of tank of gas with 15W50. I only use Chevron 91 octane gas. I barely hit 200 miles on a tank of gas with Ow40 and now I am getting 270 miles before my light comes on. This is mixed city and highway driving.

Weird huh?


93 miles is only 10mpg! What is wrong with your car?


You misread that man. By the time the needle hits half a gas tank I ve only gone 93 miles. Thats what I meant. Normally its at 150 or 175 miles when the gas tank reaches the middle.