What oil to use in old diesel engine?

[pjbori]

Hello cruisers!

I'm about to embark on my first ever oil change on my new (old) cruiser. The engine is a 1975 Volvo Penta MD6A. The boat came with some extra oil, which was a 10W-40 (API SL/CF, ACEA A2/B2). The store I'm going to to buy new oil filter, and oil pump doesn't have oil with these specifications, so I'm wondering whether I can replace it with for example 15W-40?

Thanks in advance!
Cheers

[tkeithlu]

Any "C" rated oil you are going to find on the shelf will do. The later classifications such as "CF" just mean stuff that meets a higher standard for compression-ignition (diesel) engines than the earlier stuff.

Used to be that multigrade oils couldn't meet "C" standards, and were relegated to "S" (spark-ignited) engines. Those days are gone. Multigrade just means low viscosity at cold temperatues and high enough viscosity at high temperstures, relative to the single grade oils (10 and 40 in 10W-40).

[MicHughV]

years ago, I had a Volvo MD7A...it's a beast of an engine....you could fill it with cooking oil and it would run...but these engines are raw water cooled, and it doesn't take long for the water cooling passages in the water jacket to get clogged up. As above....modern oils are categorized by viscosity....little difference between 10-40 and 15-40....not so you'd notice.

Getting original oil filters from a Volvo dealer, invariable means robbing a bank first. Most Auto parts stores sell a variety of comparable filters.

It will be worth your while to remove the cylinder head and clean out the gunk in the cooling passages. I did it several times on my MD7A, always re-using the original cylinder head gasket...never had an issue with that...

If you are like most boat owners, equipped with a Volvo marine diesel, it won't take long before you develop a love/hate relationship with that engine.

Good luck with it.

[pjbori]

Hi Mic! Thanks for the response and the info. Indeed, it's a great engine, and it's still running after 46 years - no doubt thanks to the great maintenance it has received over the years from all POs, a tradition I intend to continue. My MD6A is modified to be fresh water cooled, and I've had my fair share of trouble with it earlier in the summer, when the thermostat stopped working and the heat exchanger got clogged up. That's fixed (for now), so hence my focus on the oil. A love-hate relationship at its best...

[Bill O]

PJ,
Where are you located? In a colder climate the multi weight oil is probably the way to go. In a warmer climate or tropics, a straight 30 or 40 wt oil was recommended in some older engines. The straight heavy wt. oil tends to stick to internal engine parts a bit more, which would be helpful during engine start up.

[pjbori]

Hi Bill,
I'm located in Scandinavia, so definitely colder climate. Multi-weight being the 10w/15w?

[onavegador]

When you have the user manual of your Volvo Penta Engine, you will read that the recommended lube oil is Oil with classificatio CD. I used normally Shell Rotella 10W - 30 or 20W-40. The latter in warm climate eg. the tropics. In my boat are 37year yanmars direct cooled engines and they turn (touch wood) very well.
Good luck.

[Bill O]

Originally Posted by pjbori

Hi Bill,
I'm located in Scandinavia, so definitely colder climate. Multi-weight being the 10w/15w?

As mentioned previously not much difference in a multi wt. oil starting at 10 or 15. The API SL/CF, ACEA A2/B2 (older ACEA designation) oil you mentioned is for gas motors and light duty diesel motors. For a heavy duty diesel engine oil use an ACEA rated oil w/the "E" series designation.

[Scubaseas]

My Volvo MD11 is happy with Mobil 1 turbo diesel 5W-40 or Rotella T6 15W-40

And "C" rated oil will work fine. I find synthetic oil stays in the motor longer. As in burns less between oil changes if run all day. Used to use 1/2 qt per 24 hours running with regular dead dino oil but uses none with synthetic.

[Dooglas]

The manual for my Volvo TMD40A engines (late 70s vintage) says to use SAE 20W/30 oil in warmer climates (above 50 F) and SAE 10W oil in colder climates.

[Clivevon]

Here's a link to the workshop manual for the MD6A engine - the oil spec is on page 41 I think.

http://www.ballad.no/Volvo_MD6A_MD7A...p%20manual.pdf

[Cadence]

Originally Posted by pjbori

Hello cruisers!

I'm about to embark on my first ever oil change on my new (old) cruiser. The engine is a 1975 Volvo Penta MD6A. The boat came with some extra oil, which was a 10W-40 (API SL/CF, ACEA A2/B2). The store I'm going to to buy new oil filter, and oil pump doesn't have oil with these specifications, so I'm wondering whether I can replace it with for example 15W-40?

Thanks in advance!
Cheers

You would be fine. Get some Rotella T. if you can.

[Cajunexpat]

If it were my engine, I would first remove half of the old oil and fill it to full with Marvel Mystery Oil. Run it for an hour or so then drain and change the oil. This will remove a lot of the sludge buildup. I would use an oil made for Diesel engines such as Rotela T.

[Clivevon]

Also this link to ASAP Supplies in UK might be useful for suitable spares for your engine:

https://www.asap-supplies.com/engine...es/md6a?page=2

[MicHughV]

I'm not a big Volvo fan for a number of reasons....but I gotta say this.....My MD7A got flooded with seawater once, due to a number of reasons....I mean flooded from top to bottom...

I removed the cylinder head and sucked out all the seawater inside, and also siphoned everything I could out of the sump. The pistons had seized up solid, but I beat on one piston with a sledgehammer until it reached the bottom of it's stroke.

Then I re-assembled everything, after putting new oil in, using all the bits and pieces I had taken off in the first place,as I had no other option.

Damn, if that thing didn't start right up. It smoked a little now, but it ran. I ran several more changes of oil thru' the engine to make sure I had got rid of all the water.

It continued to run for the next several years, ran like clockwork, always started right up, smoked a bit, but didn't really use much oil, that I could tell.

I finally traded it in for another Volvo, the 2003, only because it would fit my existing supports, etc. It too ran like a champion.

My beef with Volvo was the price of spares, a trait I learned is shared by most Volvo owners, that and these weird rubber fittings Volvo uses for the raw water cooling lines. Try as I might, I could never get those little rubber inserts to fit perfectly, and they always leaked. Not much, but an annoying slow drip.....drive me crazy...

I've discovered the internet has many bits and pieces even entire engines of these older Volvo models.....