Chit Chat - Oil Changes

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Oil Changes

Printed From: myHanse.com
Category: General
Forum Name: Chit Chat
Forum Description: Talk about anything to do with your boat
URL: https://www.myhanse.com/forum_posts.asp?TID=15363
Printed Date: 26 March 2026 at 23:37
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com

Topic: Oil Changes

Posted By: Martin&Rene
Subject: Oil Changes
Date Posted: 14 September 2025 at 15:31

A follow on from our saildrive problems

https://www.myhanse.com/saildrive-problems_topic15362.html" rel="nofollow - https://www.myhanse.com/saildrive-problems_topic15362.html

When the engineer came on our 2003 Hanse 341 to listen to the saildrive problem, he also said he did not like the sound of the engine. Running the engine in his workshop and then examining it, he found the problem was that minimal oil had been getting to the top of the engine and that all the components of the rocker system showed wear of some form or other. Thankfully, this engineer has wide experience of working on large diesel engines around the world and has the skills and philosophy of repairing items, rather than throwing away a system and replacing it with new. He therefore had a number of items machined/skimmed up and rebuilt the engine. The engine now starts and runs much better.

The Problem

I do not know what happened in the first 6 years of the yacht’s life, but I have always done an annual oil change. However, having to drain the oil out of the engine through the dipstick hole results in there always being a residue of dirty oil left in the engine. 20 years of build-up of dirt had basically blocked the oil galleries feeding to the top of the engine.

Recommendation

Our engineer’s advice is that we should always follow a policy which he uses of flushing the engine each oil change. So, the warm oil should be extracted, preferably straight after a sail, when all the oil is mixed up. (It can be useful to weigh the quantity of oil extracted, to know how much to refill finally) Then sufficient new oil should be put into the engine to fill just past the minimum oil level mark and the engine run under load for 20 mins or so. Then drain the oil, change the filter and refill with new oil to the normal oil level.

The cost of the extra oil is less than the cost of an engine overhaul.

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Martin&Rene Hanse 341 Dipper Wheel steering, 3 cabin layout, normally based in Scotland

Replies:

Posted By: samuel
Date Posted: 15 September 2025 at 10:46

Did he not suggest Castrol solvent flushing oil. I used to use that on old diesels years ago & that flushed lots of sludge out of the diesel engines

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Daydream Believer- Hanse 311- No GBR9917T- Bradwell Essex

Posted By: sgrhma2
Date Posted: 15 September 2025 at 17:42

History is littered with engine failure due to poor oil changing and stretched service intervals. In recent times engines have become more reliable and service intervals have been greatly increased. The majority of people think that this is due to improved design and manufacturing quality. This indeed is a part of the reason, but the single biggest improvement in reliability and increased service intervals has been achieved through significant improvements in oils. Engine components and bearings are still made from the same basic metals as they were in the 1970s, whereas oils in general have moved increasingly from mineral to synthetics. Synthetic oils have greatly improved film strength, lubricity and higher temperature stability. At the same time sump capacities have virtually doubled, resulting in the oil doing fewer circuits of the engine and giving it more time to cool. Similarly you’ll notice that at the service interval modern oils are a lot cleaner than the black treacle they use to become, a result of the increased thermal stability.

I use a fully synthetic oil in my engine and have done once it was run in when new (2005). When I’m inside it checking valve clearances, all the internal surfaces are like new, with no discolouration or sludge deposits and this is directly related to the thermal stability of synthetic oils. I also always change the oil through the dip stick hole. The residue that is left (and annoys me) being synthetic is still in reasonably good condition, and when new oil is added the ‘mix’ is still significantly better and more stable than a lot of mineral oils.

Before everyone races out and change over to synthetic oils, there are a few times that you should stick to the manufacturer’s recommend, if a mineral. These are, when running the engine in when new, and running in after a rebuild.

When changing to a synthetic it’s very important to match the viscosity recommended by the manufacturer.

Hope this is useful

Simon

Posted By: Screener
Date Posted: 06 November 2025 at 19:56

We can syphon oil from the sump drain, with the hose installed there, on the FP generator. Has anyone done this for a VP-D2? is it possible?