Sucking oil out f sump

Sludge was a "feature" in the old days when first I started rebuilding engines. My impression is that modern detergent oils keep debris suspended much better (based on the lack of deposits on sump plugs, when removed).

Toyota had a lot of problems with sludge in the late 1990's to mid

Plus modern cars seem to use 'thinner' oil.

Sludge can form in any grade of oil except Fully synth as its the product of oil mist and water vapour being overheated. When cooked Fully synth doesn't break down into the same sludge forming products that dino oil produces.

If your average speed is less than 15 mph you should be on more frequent oil change routine. Or make sure you do at least one trip a week that gets the engine hot enough long enough to boil the water out of the oil.

A coolant/oil heat exchanger can help as it not only cools the oil to prevent it cooking but also brings it up to temperature quicker.

Do you know of one with a pipe small enough to fit down the dipstick tube? I'm not sure how else you would reach it.

Certainly more likely to be Fully Syn. these days. I'm not sure what 'dino' is, perhaps another name for mineral oil?

I've not used even Semi Syn. for years. I 'converted to it early on then to Fully Syn as I bought cars that needed it.

Rightly, or wrongly, I believe that regular oil (and filter) changes with quality oil go a long way to ensuring long engine life.

I do know someone who never changed his oil. He had at least one really old lorry type vehicle that he reckoned was on its original oil. He must have been very lucky ;-)

Interesting, thank you. However, you've rather exposed my basic approach / use of terms. I was using the term 'sludge' to the refer to general 'stuff' that seems to collect in the sump- at least of you change the oil at (say) 10k miles (or more, heaven forbid!). I tend not to see it as I change oil every 12 mths and don't cover anything like 10k miles in that time these days. In the days I did cover higher mileages, I changed at 10k (unless the car spec was lower). Also, I've not owned any vehicles on that list- although I assume other makes suffer.

Don't misunderstand me, I'm not suggesting you are incorrect- you knowledge in this area clearly exceeds my own, I was simply referring to something more basic.

You can buy such pumps. I assume the pipes fit. I've not measured the inside dia of a dipstick tube but would guess at maybe 6mm or so.