Engine flush - how often is too often?

[vr2turbo]

Honestly no idea because I also never experienced such cases before, even on my old Mitsubishis back then. I guess the way I do maintenance with such occasional flushing is more of a preventive measure.

True also. Of course if really dirty with sludge, I think what was mentioned can happen......lol

 

[alcyon]

It becomes way too expensive if have to change FS oil within just 1000km, for 3 times some more. The engine flush I use only costs rm18.50.

If one 4L bottle for RM90, thats ok, still worth it than taking risk with the flush dislodging and blocking some passages, or the seals leaking.

 

[6UE5t]

If one 4L bottle for RM90, thats ok, still worth it than taking risk with the flush dislodging and blocking some passages, or the seals leaking.

I'd rather use cheap mineral oil plus the rm18.50 flush.

 

[ixeo]

I think modern engines don't suffer sludge issues that much since all specifies FS oils. It was the old Audi that was notorious.

 

[Izso]

Sigh. This topic keeps on popping up every no and then and there are literally thousands of videos on Youtube talking about this.

This is my take on the subject as a whole :

- If from day 1 you've been using mineral / Semi-Syn oils and changing regularly at 7-8k km intervals, you're probably better off not flushing and just sticking with your OCI and choice of oil. If you have sludge it may or may not be clogging up wear and tear bits and pieces like oil seals and gaskets preventing leaks. Flushing will likely flush out that sludge and what previously isn't leaking - will start to leak.

- If from day 1 you've been using mineral / semi-syn oils and have been going crazy with the OCI and changing every 2000-3000km (yes I do know people who do this), then you really don't need a flush cuz you wouldn't have given the oil enough time form sludge. Won't matter if you flush too. But this is highly dependent on whether your car is a daily driven one or barely driven one (hence low mileage). If daily then no issue, if barely - better make sure you max give it 6 months and do an oil change even if you haven't touched 2000-3000km.

- If from day 1 you've been using fully synthetic oils - then you really don't need an engine flush. Most if not all FS oils have great additive packages and some extremely good detergents built in. Like Royal Purple, guaranteed to clean out any varnish and sludge left behind by your prev oil. A certain rich fella I know uses Royal Purple to flush his engine every oil change before filling his own choice of oil. Unnecessarily excessive.

- There are several types of flushes out in the market. Some that bond with the engine oil and suspend the sludge and dirt (like Bluechem products) and still provide certain amount of lubricity meaning the engine can still be driven 100-200km, and then there's some that are supposed to run in your engine for 10-15 mins and drained (not meant to be in the engine too long due to it's acidic nature). I've used a few brands in the market and the best one I've used is the Bluechem one. I say "best" because of the value vs how it's used. In terms of cleanliness all brands seem to be the same. But the CRC one is a little scary - even after draining the oil the smell of the flush is still in the engine. I usually flush the flushed engine with cheap oil to remove any leftover flush if any. Bluechem doesn't need that, if the article is still in ZTH, I wrote a whole article about it and how it works.