Engine oil flushing - anyone use this

[davidivorwynphillips]

Last year someone recommended using a proprietary oil flush when I change the oil in my old diesel engine (a Mercedes OM636). There does seem to be a lot of controversy over this. I did so last year - lovely clean oil for the first 10 hours or so of running but my impression is that the small oil seal leaks in the engine have increased somewhat. Does anybody used this and with what results?

 

[RichardS]

Last year someone recommended using a proprietary oil flush when I change the oil in my old diesel engine (a Mercedes OM636). There does seem to be a lot of controversy over this. I did so last year - lovely clean oil for the first 10 hours or so of running but my impression is that the small oil seal leaks in the engine have increased somewhat. Does anybody used this and with what results?

In 99% of cases it's a waste of time and money. If you're worried about the oil being dirty then just change it a bit more often.

Richard

 

[TC Tuckton]

I use an engine flush at each oil change. It's difficult to get the last of the old oil out of the sump (MD11C) and I think the flush helps.

 

[Daydream believer]

Used it regularly with all my diesel plant , mixers , hoists dumpers etc. did remove lots of crud which inevitably built up in abused builders plant.
I think that if ones engine is old and has not had the oil changed often then the odd flush is worth it

 

[ronsurf]

Yes for a new or newish engine, no if it's an old one.

 

[lpdsn]

I use it periodically (about every three years or so) mainly because I have to change the oil through the dipstick hole (as per most Yanmars I believe). Otherwise I just do an normal oil change.

I've been told, both on the forum and privately that it isn't necessary, but it does seem better at clearing out the dregs from the sump than just an ordinary oil change. It doesn't cost more than the oil for a second change and it's handy to get it all done in one go.

Never had an oil leak because of it.

 

[Daydream believer]

Yes for a new or newish engine, no if it's an old one.

I would say the other way round

 

[sailorman]

I would say the other way round

The flushing oil may dislodge particles ( in an old engine) you would prefer to keep in place

 

[davidivorwynphillips]

Thanks - rather confirms my impression of a lack of agreement on this!

 

[lw395]

Thanks - rather confirms my impression of a lack of agreement on this!

I think it has uses when an engine has been run on non-detergent oil, or has had oil contamination, is full of 'black mayonnaise' or something.

 

[Jamesuk]

In 99% of cases it's a waste of time and money. If you're worried about the oil being dirty then just change it a bit more often.

Richard

Yes I did research in to it last year for the boat and I concluded that it is a waste of time on the back of the research.

Engine oil alone changed often enough is designed to clean your engine and keep it running smoothly at the right temperatures

 

[lw395]

.....

Engine oil alone changed often enough is designed to clean your engine and keep it running smoothly at the right temperatures

Some people on here though advocate old-skool oils from cheap foreign sources which may not be detergent oils 'designed to clean your engine'.

 

[Daydream believer]

The flushing oil may dislodge particles ( in an old engine) you would prefer to keep in place

Such as?

 

[black mercury]

No i wouldn't use it unless I have a problem such as gummed up piston rings causing high oil consumption in which case it could be worth while doing. If the oil is changed every season you shouldn't need to use a flushing additive. If you use it since the engine was new then it shouldn't be a problem. The issue is with an old engine with an unknown past. If there are sludge deposits in the engine, either the soft sludge or the hard baked on sludge, if you use a flushing additive it could dislodge this and either block oil passages or the oil strainer in the pick up pipe in the sump. Boat engines are worse because if you are sucking the oil out with an extraction pump you wont get the sludge out from the sump, and you will leave a quantity of flushing oil in the engine as you usually can't get all the oil out. Have seen a few car engines wrecked because of flushing additive, although they were neglected and with a very dirty sludged up engine. If you have been using it then it shouldn't be a problem to keep using it, the problem arises when a dirty engine is given the oil flush for the first time. Just my opinion.

 

[Floyd Raser]

Last year someone recommended using a proprietary oil flush when I change the oil in my old diesel engine (a Mercedes OM636). There does seem to be a lot of controversy over this. I did so last year - lovely clean oil for the first 10 hours or so of running but my impression is that the small oil seal leaks in the engine have increased somewhat. Does anybody used this and with what results?

Where oil is supposed to cling everywhere and lubricate, flushing additive is designed to liberate everything, like washing powder.
It's true that it can also liberate hard deposits but those hard deposits take some shifting, so as long as the additive isn't left in for a long time it should be OK.
The additive may also reduce the viscosity, hence the increased leakage but that may well be temporary until the thin stuff has gone.
As others have said, regular oil changes are the best way to look after an engine.
The best way to clean the inside of an old or unknown engine is to strip it.
Just my opinion based on working on old car engines.

 

[Latestarter1]

Last year someone recommended using a proprietary oil flush when I change the oil in my old diesel engine (a Mercedes OM636). There does seem to be a lot of controversy over this. I did so last year - lovely clean oil for the first 10 hours or so of running but my impression is that the small oil seal leaks in the engine have increased somewhat. Does anybody used this and with what results?

Engine lube oil flushing has its roots in gasoline engines which ran on single weight lube oil with no lube filter, this practice has no place in diesel engine operation.

After WW2 there were major advances in diesel engine lubrication tribology led to the universal adoption of detergent oils which have an additive package consisting of Zinc DiakylDithioPhosphates – better known as ZDDP.

The introduction of ZDDP was key in keeping harmful diesel soot deposits in suspension and slowing down depletion of lube oil due to acid combustion loading. Following a lubricant change lube oil should go black very quickly which is a sign that lube oil it doing its job.

Flushing oils are positively dangerous in diesel engines #1 is the residual contamination of the additive pack evidenced by the fact that the new lube stayed 'clean' for 10 hours of running, I would suspect that the TBN (Total Base Number) of the new lube dropped like a stone during these 10 hours with a corresponding increase in TAN (Total Acid Number). Life of the replacement lube oil was compromised from the outset.

#2 Reason for not using flushing oils in diesel engines is that many types of diesel engines have components subject to high hertz stress and I can think of at least two manufacturers where flushing oil will do irreparable damage to the cam/tappet interface.

Flushing is just a leftover of dinosaur gasoline engine thinking.

 

[Champagne Murphy]

Engine lube oil flushing has its roots in gasoline engines which ran on single weight lube oil with no lube filter, this practice has no place in diesel engine operation.

After WW2 there were major advances in diesel engine lubrication tribology led to the universal adoption of detergent oils which have an additive package consisting of Zinc DiakylDithioPhosphates – better known as ZDDP.

The introduction of ZDDP was key in keeping harmful diesel soot deposits in suspension and slowing down depletion of lube oil due to acid combustion loading. Following a lubricant change lube oil should go black very quickly which is a sign that lube oil it doing its job.

Flushing oils are positively dangerous in diesel engines #1 is the residual contamination of the additive pack evidenced by the fact that the new lube stayed 'clean' for 10 hours of running, I would suspect that the TBN (Total Base Number) of the new lube dropped like a stone during these 10 hours with a corresponding increase in TAN (Total Acid Number). Life of the replacement lube oil was compromised from the outset.

#2 Reason for not using flushing oils in diesel engines is that many types of diesel engines have components subject to high hertz stress and I can think of at least two manufacturers where flushing oil will do irreparable damage to the cam/tappet interface.

Flushing is just a leftover of dinosaur gasoline engine thinking.

Unless you've got water in the oil.........
yes, personal experience

 

[lw395]

Unless you've got water in the oil.........
yes, personal experience

If you get water in the oil, the best thing is usually to drain it out with the oil, get as much out as you can, then add new oil, run the engine, maybe clean/change the filter, get the engine hot, change the oil again.
I've seen trail bikes get a lot of water inside, sorted with no problems.

 

[Latestarter1]

If you get water in the oil, the best thing is usually to drain it out with the oil, get as much out as you can, then add new oil, run the engine, maybe clean/change the filter, get the engine hot, change the oil again.
I've seen trail bikes get a lot of water inside, sorted with no problems.

Yes, I was somewhat bemused by the smiley. Even on a sinker normal practice to drain and refill with new filter.

Taking a wrecking ball to the additive package of new lubricant makes no sense whatsoever.

 

[Champagne Murphy]

Yes, I was somewhat bemused by the smiley. Even on a sinker normal practice to drain and refill with new filter.

Taking a wrecking ball to the additive package of new lubricant makes no sense whatsoever.

The smiley was embarrassment! Water pump failed but didn't really show until water was in the case.
Engine flushed (twice) with a 50/50 mix of diesel and the usual oil as recommended by Al and Norm at Bukh, then new filter and oil