HM oil for W163 ML430?

[Newuser]

I have a W163 ML430 that have had almost since new. With nearly 250k miles, it’s finally starting to drip a little from the rear main seal.

I’ve used Mercedes rated 0w-40/5w-40 from Mobil 1 & castrol its whole life. To my knowledge. There’s no Mercedes rated high mileage oil.

Looking to try a high mileage oil strictly for the seal conditioners to see if it will slow the rear main seal down. Given it’s currently not bad, it might help?

Any suggestions for an oil that would be ideal for this vehicle?

 

[BrendanC]

i’d keep a euro oil in it and try this https://a.co/d/10aPLwu

snake oil or not, it slowed the oil burning in my accord significantly.

 

[JavierH19]

Maybe m1 fs 10w-40 hm? it's at least 3.5 hths starting. I think I'd rather keep mb rated oil and use a plasticizer like AT 205 or LM oil saver like Brendan mentioned or any other type of leak reducing oil additive as they are all somewhat the same some better than others. But if using at 205 start at a low concentration only increasing by a half ounce every couple hundred miles. after letting it have time to work in around 500 miles first. Overusing plasticizers can make it worse but some have luck not doing that and throwing the whole bottle in but it's risky.

 

[Newuser]

Maybe m1 fs 10w-40 hm? it's at least 3.5 hths starting. I think I'd rather keep mb rated oil and use a plasticizer like AT 205 or LM oil saver like Brendan mentioned or any other type of leak reducing oil additive as they are all somewhat the same some better than others. But if using at 205 start at a low concentration only increasing by a half ounce every couple hundred miles. after letting it have time to work in around 500 miles first. Overusing plasticizers can make it worse but some have luck not doing that and throwing the whole bottle in but it's risky.

Going through my stash. I found enough valvoline 10w-40 high mileage semi synthetic to do an oil change.

Would running this for 4-5k miles be okay for this 4.3 V8?

It’s primarily used to haul horses short distances these days. Just trying to avoid having to do a rear main seal in the near future, as I live in the middle of nowhere. The nearest capable mechanic is 2 hours away

 

[JavierH19]

Going through my stash. I found enough valvoline 10w-40 high mileage semi synthetic to do an oil change.

Would running this for 4-5k miles be okay for this 4.3 V8?

It’s primarily used to haul horses short distances these days. Just trying to avoid having to do a rear main seal in the near future, as I live in the middle of nowhere. The nearest capable mechanic is 2 hours away

It's already a bit low on additives and 10w-40 only has to have a starting viscosity of 3.5 hths but there's no shear limit so it's just about acceptable if you're not towing but if you're towing it's not great. I'd rather run the 20w-50 if starting temperature permits just for the extra viscosity to help out and even then 5k miles is a bit long I do 2k. It won't hurt the engine to give it one 2-3k run of Max life 10w-40 I just wouldn't do that forever.

 

[Newuser]

It's already a bit low on additives and 10w-40 only has to have a starting viscosity of 3.5 hths but there's no shear limit so it's just about acceptable if you're not towing but if you're towing it's not great. I'd rather run the 20w-50 if starting temperature permits just for the extra viscosity to help out and even then 5k miles is a bit long I do 2k. It won't hurt the engine to give it one 2-3k run of Max life 10w-40 I just wouldn't do that forever.

Understandable. Realized I have it sitting around from another vehicle, and would hate to be wasteful and purchase another HM oil when I have this sitting around.

 

[JavierH19]

Understandable. Realized I have it sitting around from another vehicle, and would hate to be wasteful and purchase another HM oil when I have this sitting around.

Looked up maxlife 10w-40's pds on valvoline website and it says 4.0 hths and worst case scenario it shears by .5 hths it's still ok. I didn't expect it to start so high I imagined 3.5-3.7. With that I'd use it for 3k miles.

 

[fantastic]

Looked up maxlife 10w-40's pds on valvoline website and it says 4.0 hths and worst case scenario it shears by .5 hths it's still ok. I didn't expect it to start so high I imagined 3.5-3.7. With that I'd use it for 3k miles.

Yeah, that surprises me as well if true. I suppose knowing it's kind of an old school grade High Mileage oil & HM oils tending to be higher viscosity seems to help it's HTHS. Keep that old high mileage iron from wearing out..Maxlife for the win! I like the idea of at least a 10w starting viscosity compared to say a 5 or 0w to potentially minimize leaks. Good recommendation IMO.