Oil change 15w40 to 0w40 - engine sounds terrible - PeachParts Mercedes-Benz Forum

TwitchKitty · #1 10-26-2014, 10:24 AM

This might be hurting this engine. It defies the descripton of the oils. It's a gasser, I changed from a diesel oil to gasser oil.

Motor Oil 108 - Bob is the Oil Guy - Bob is the Oil Guy

I really want to believe bobistheoilguy but I can't ignore my ears. After the oil change this engine sounds like it might fly apart. Lifter ticking is loudest but the engine sounds loose overall.

It is not just on start up. It sounds worse after it warms up. I might go back to diesel 10w40.

t walgamuth · #2 10-26-2014, 11:23 AM

I am always reluctant to go with a thinner oil than the mfgr had in mind when the engine was designed....more so if it is high mileage.

I'd get that thin stuff out of there and go back to what it was designed for. New engines are designed tight and can work on the very thin oil, old engines are designed for the more viscous stuff.

TwitchKitty · #3 10-26-2014, 11:32 AM

Quote:

Originally Posted by t walgamuth

I am always reluctant to go with a thinner oil than the mfgr had in mind when the engine was designed....more so if it is high mileage.

I'd get that thin stuff out of there and go back to what it was designed for. New engines are designed tight and can work on the very thin oil, old engines are designed for the more viscous stuff.

That link to bobistheoilguy says otherwise but my intution says exactly what you are saying. My ear backs up what you are saying.

I might change the filter first just as an experiment.

I can justify the thin stuff as a flush, what's $22, just money.

MTUpower · #4 10-26-2014, 01:18 PM

they are both 40 weight oil- so when warm they are 40. The "0" and "10" mean when cold they act as a lighter oil- so in the morning when cold the engine starts more quickly. In theory. Perhaps your car's engine is worn and you need the 10-40. Remember it takes almost 30 minutes for the oil to warm up.

aklim · #5 10-26-2014, 09:15 PM

Quote:

Originally Posted by MTUpower

they are both 40 weight oil- so when warm they are 40. The "0" and "10" mean when cold they act as a lighter oil- so in the morning when cold the engine starts more quickly. In theory. Perhaps your car's engine is worn and you need the 10-40.

Remember it takes almost 30 minutes for the oil to warm up.

My guess would be the engine is too worn for 0 weight oil

I don't think so. My oil temp gauge gets to temp in the Vette pretty quickly. May not be instant but certainly not 30 minutes unless it is freezing cold and you are idling it.

Kuan · #6 10-26-2014, 08:37 PM

Add moly?

layback40 · #7 10-27-2014, 08:04 AM

You dont give any details of the application/motor.
In very cold conditions a 0w type oil may be good.
Filter should always be changed with an oil change for a diesel.

TwitchKitty · #8 10-27-2014, 08:55 AM

It is a Mazda B6 engine and it does have a lot of miles on it. It appears that it is known as a noisy engine. I always thought it sounded good. Has a nice tuned hum to it.

The definitive 100K mile Miata HLA cleaning story

Mazda B engine - Wikipedia, the free encyclopedia

I changed the filter again and left the new Castrol Edge 0w40 in it. It sounded better but not right. So I changed the oil again. Mobile 1 10w40 High Mileage this time. I haven't done my driving yet today and I'll post again later about my opinion of the Mobil 1.

There were two different filters involved, one larger than the other. That was the reason for trying different filters.

TwitchKitty · #9 10-31-2014, 01:57 PM

So the Mazda finally cycled back around on the priority list and I am back to 5w40 Delo and it sounds like it might live for a while. It got better with the 10w40 Mobil 1 but was still noisy enough to be annoying.

This engine has tiny little hydraulic valve adjusters in the outer end of the rocker arms called HLAs, hydraulic lash adjusters. The HLAs are sensitive to oil types. Learn something new.

Zulfiqar · #10 10-31-2014, 02:06 PM

Quote:

Originally Posted by TwitchKitty

So the Mazda finally cycled back around on the priority list and I am back to 5w40 Delo and it sounds like it might live for a while. It got better with the 10w40 Mobil 1 but was still noisy enough to be annoying.

This engine has tiny little hydraulic valve adjusters in the outer end of the rocker arms called HLAs, hydraulic lash adjusters. The HLAs are sensitive to oil types. Learn something new.

same kind of lash adjusters as in the M112 engine by mercedes, it also is quite sensitive to what sort of oil you put in it.

t walgamuth · #11 10-31-2014, 04:03 PM

On my 84 500SEC it had the hydraulic lash adjusters. When I got the car I put in 15w40 diesel oil. It promptly started ticking one of the valves on startup. After the oil was good and hot it would quiet down. I switched to 10W30 mobile one and all was good.