E30 Zone

What are your opinions on engine oil flush/cleaning treatments? There are lots of companies selling flush treatments that you add to the oil before the old oil is drained and there used to be flushing oil that was put in after the old oil was drained out and then it was drained out before filling with new oil. Are they worth it? Can they actually cause damage? Someone once told me that flushing can cause an engine to smoke due to removing "clag" from the piston rings. Thoughts?

If the service interval is upheld then there will be little or no sludge in the engine if it is running well, like most miracle in a bottle cure, they are just bullshit.

Some one gave me a bottle of forte bio something or other, to flush their cooling system the other day, £20, and strangely it smelled exactly the same as my Swarfega hand wash They thought the heater may have been blocked, opened the header, there was K-seal in there

If you want to give the engine a "flush" put oil for a diesel engine in, run it around for 1000 miles, then do another change. Its not going to do much but it will help.



This is what happens if you don't change your oil. This had 147k on it.

Some people say it's best not to "flush". For example.....if you have some sludge sitting harmlessly arround the bottom end or cylinder head, by thinning the oil down you could disslodge it and cause a blockage on one of the small oil wells supplying a bearing or the spray bar. This could cause oil starvation right where you don't want it.

A regular oil change is a much better policy.

I've used engine flushes on every car I've owned over the last 21 years - never caused me any problems.
On some cars when I've done the first oil change in my ownership using a flush when I've transferred the old oil into a can there has been noticeable thick gunk at the bottom of the drain pan - which is then gone on subsequent oil changes.

Its personal choice. if you're worried then dont use a flush just get the engine good and hot, drop the oil out and refill with decent quality stuff and a genuine filter.

Rather then engine flush I use a cheaper brand oil, let it run for short period and then drain that out. Any remaining thick nasty oil comes (not always 100% with out some camera proof or splitting the engine to check) out first before the cheap stuff, hey presto nice clean oil flowing through.