Engine cool-down time before draining the oil

[laika]

Numpty question of the week....

How long should I leave an engine (in this case a yanmar 3jh4e) to cool down before taking out the dipstick to drain the oil with a pela? Or alternatively, how long from cold should I run it to get the oil runny but not hot enough to melt the plastic of the oil extractor dip tube or spray hot oil about the place when the dipstick is removed.

I've previously changed the oil cold following the lead of the bloke from the yanmar main dealer who did the first service on the engine after I'd got it. However I later realised that his "oil change" actually left a significant amount of the old oil in the sump and doing it rather more thoroughly with cold oil takes quite a long time.

 

[cmedsailor]

Change the oil immediately after you turn the engine off. I don't think the oil gets so hot that will melt the plastic of the oil exctractor. Certainly it didn't melt mine after 4 hours of operation.

 

[RAI]

I find it a lot harder to extract the oil if it is not warm. (Yanmar 4JH4E).

 

[jac]

ANotehr for straight away. I usually start mine - put it under some load ( about 2000 rpm in gear) ( Having checked the stern lines!!) and run for about an hour whilst doing other jobs . Then pump it out. Still takes a while even with a lot of vacumn on the Pela

 

[lw395]

I think they tell you not to do it hot because of the risk of burns from hot oil.
I did my car cold with a Pela, it took a long time to drain 10 or 15 minutes?, but seems to have got pretty much all the old oil out, as the new oil is still pretty clean.

 

[jac]

I think they tell you not to do it hot because of the risk of burns from hot oil.
I did my car cold with a Pela, it took a long time to drain 10 or 15 minutes?, but seems to have got pretty much all the old oil out, as the new oil is still pretty clean.

The same logic that labels packets of peanuts - Care may contain Nuts

 

[Norman_E]

I have seen a tip for getting the oil out faster. A piece of 12mm plastic tube can be pushed over the dipstick tube and makes a good seal. You need to check if their is a small air bleed hole near the top of the tube and push the plastic past it. Connect the other end to the Pela. The problem with the Pela is that the bit that goes down the dipstick tube is just plastic covered curtain wire and has only about a 3mm bore.

I have not done this yet, but intend to when I go back to the boat.

 

[jac]

I have seen a tip for getting the oil out faster. A piece of 12mm plastic tube can be pushed over the dipstick tube and makes a good seal. You need to check if their is a small air bleed hole near the top of the tube and push the plastic past it. Connect the other end to the Pela. The problem with the Pela is that the bit that goes down the dipstick tube is just plastic covered curtain wire and has only about a 3mm bore.

I have not done this yet, but intend to when I go back to the boat.

I'm struggling to see how that would work - I get that the dipstick tube "SHOULD" act as the bottom bit of the pela ( just larger bore) but isn;t the rest of the oil system effectively sealed - so you will end up creating a partial vacumn that you then need to overcome? be brilliant if it worked though

 

[laika]

Thanks all. My superstitious reticence to get too close to the oil in a hot diesel engine goes back to vague memories of an incident well over a decade ago which, now I come to think of it, may even have involved stupidly loosening the dipstick from a *running* engine. I'll look at getting a seal on the dipstick hole too (thanks).

I'm still quite, shall we say, "surprised" at how the murkiest I've ever seen "fresh" engine oil was after that time it was changed by a main yanmar dealer. I even questioned it and was told that was absolutely normal. Of course he was on the clock and it has taken considerably longer when I've done it cold. Hopefully will be shorter with my new found confidence with hot oil....

 

[Vara]

I remove oil as soon as the engine has stopped.

On a Volvo 2003 I can use the Pela middle bore extractor tube and it removes 4l pretty quickly

 

[westhinder]

I'm struggling to see how that would work - I get that the dipstick tube "SHOULD" act as the bottom bit of the pela ( just larger bore) but isn;t the rest of the oil system effectively sealed - so you will end up creating a partial vacumn that you then need to overcome? be brilliant if it worked though

I haven't tried the suggested method, but am certainly going to try it.
I have found it easier to get the oil out when I remove the oil filler cap, so there is no vacuum in the sump.

 

[VicS]

I have seen a tip for getting the oil out faster. A piece of 12mm plastic tube can be pushed over the dipstick tube and makes a good seal. You need to check if their is a small air bleed hole near the top of the tube and push the plastic past it. Connect the other end to the Pela. The problem with the Pela is that the bit that goes down the dipstick tube is just plastic covered curtain wire and has only about a 3mm bore.

I have not done this yet, but intend to when I go back to the boat.

I'm struggling to see how that would work - I get that the dipstick tube "SHOULD" act as the bottom bit of the pela ( just larger bore) but isn;t the rest of the oil system effectively sealed - so you will end up creating a partial vacumn that you then need to overcome? be brilliant if it worked though

It applies to some engines where the dipstick tube is fitted low down to the side of the oil pan . See green circle in diagram below ... which is of a Yanmar

Also look back for a few days and you will find the post Norman E refers to.
(Here it is in this thread http://www.ybw.com/forums/showthread.php?433628-What-oil-for-a-Yanmar-4JH3E )

It may well apply to the OP's engine.

Sump breather should allow air back in but you normally release the filler cap when draining oil surely


When the thin Pela tube is used through the dipstick hole raise it a mm or so from the bottom of the sump until most of the oil is out otherwise it can sit so tight on the bottom that it restricts the flow.

 

[Talulah]

I'm struggling to see how that would work - I get that the dipstick tube "SHOULD" act as the bottom bit of the pela ( just larger bore) but isn;t the rest of the oil system effectively sealed - so you will end up creating a partial vacumn that you then need to overcome? be brilliant if it worked though

I did this a short while ago. I will no longer be inserting the Pela tube down the dipstick. It is so much quicker and easier to do it over the dipstick. No need to warm the oil.
The Yanmar dipstick tube is 15mm OD. The Pela tube is 10mm O/D so you need two pieces of pipe. A length of pipe with 15mm ID to go over the dipstick tube and a short length of pipe (25mm) 10mm ID, 15mm OD to go between the two. I went to the chandlery to look for suitable tubing. Clamp the pipe over the dipstick tube with a hose clip and far enough over to cover the tiny air bleed hole.
Because the Yanmar dipstick goes to the bottom of the sump you are able to extract virtually all the oil. In addition, because the engine has not been run the oil filter is almost empty. Remove the oil filler cap to allow air into the engine whilst extracting the oil. Takes less thn 10 minutes start to finish. Extracting with the thin tube down the dipstick seemed to take forever even with hot oil.

 

[prv]

Because the Yanmar dipstick goes to the bottom of the sump you are able to extract virtually all the oil.

That's the crucial point - great on your engine where it applies, but on many others (like mine) the majority of the oil would be left below where the dipstick tube enters the sump. Wouldn't want someone to make the mistake on a different engine

The Volvo D1 engines (and maybe others) have a dedicated drain tube connected to the bottom of the sump, led up the side of the engine and capped with a rubber bung. I have mine connected to a PVC tube which runs to a convenient point to plug in a short length of hose attached to the Pela. The only thing easier would be a permanently-installed electric drain pump like the big mobos

Pete

 

[RichardS]

In addition, because the engine has not been run the oil filter is almost empty.

All the car engines I have worked on have been designed so that the oil filter does not drain into the sump when the engine is stopped. I would be surprised if marine engines are built differently but one never knows.

Richard

 

[Talulah]

On the Yanmar the dipstick tube is attached to the sump with a Banjo bolt.
Some people drill the end of the banjo bolt and fit a drain off point.
Other people replace the banjo bolt with a double banjo bolt and add a drain off tube that way.
I did consider this for a while but once I found that extracting the oil with the Pela tube over the outside of the dipstick was so easy the idea became redundant.

 

[Talulah]

All the car engines I have worked on have been designed so that the oil filter does not drain into the sump when the engine is stopped. I would be surprised if marine engines are built differently but one never knows.

Richard

There is still some oil left in the filter but most has drained away.

 

[laika]

Brilliant! I ask a numpty question and I receive as much excellent information as I could have hoped for with a reasonably sensible question. Thanks again to everyone. Yes the 3JH4E's dipstick arrangements (and filling points) are similar to those of it's 4 cylinder sibling. I think maybe I'll try rummaging in the spare pipe locker, maybe coupled with a chandlery trip as Talulah suggests, falling back to the hot oil method next time if necessary.

 

[vyv_cox]

I worked on a Volvo D2-4 engine last year on which the dipstick protruded a couple of inches below the tube. I doubt if the tube even touched the oil.

 

[VicS]

I worked on a Volvo D2-4 engine last year on which the dipstick protruded a couple of inches below the tube. I doubt if the tube even touched the oil.

dunno what a D2-4 is. VP site does not recognise it. but there are some VP engines with a fitting for an extractor pump ( VP supply an electric pump as an accessory ) on the sump which could be used as described for the above Yamnars.

Would not have been applicable to any vehicle engine I have ever had though!


BTW dont buy the Screwfix version of the Pela .