Dipstick/engine blow

J_macky

Right lads I was looking at 07 landcruiser to buy and when I pulled
out the dipstick the oil was spitting a bit on my hand.
Someone told me that is a sign of a blow in engine and walk away.
Is that true ?

Atlantic Dawn

I would always only check the oil with the engine stopped.

CJhaughey

Your engine is an air pump, if you have 4 big pistons going up and down and each one displacing 750cc then there will of course be pressure in the crankcase, pulling the dipsticks on most running engines will result in the same thing happening.
High performance engines have special pumps to evacuate the air from the crankcase to minimise pumping losses but The 1KD engine is not in that camp.

In short what you experienced is normal and nothing to worry about, your friend is talking through their hat and should not be listened to.

Oil filler cap is normally a safer place to look for blowby but even that may result in some oil fling due to camshart(s) rotating there at something in tune of 5 rotations per second at idle (at engine speed of 600 rpm).

biko

Checking oil with engine running is pretty pointless.
Check oil in a cold engine, it's the best way to tell the level.


NB - with some cars, the automaker recommends that the oil be checked after the engine has been warmed up.
It's all about the design.
If in doubt, google the brand.

H3llR4iser

Was going to changs the oil on my car - took the dipstick out, checked and as it was cold, the oil was not flowing ideally. So I decided to turn the engine on to warm it up a bit. Distractedly, I just put the dipstick down without fitting it back in. Turn the engine, let it run for 1-2 minutes before realizing the mistake.

That was 3 years ago - I'm still cleaning up the mess. Every now and then, I find a spray that got into some really remote area of the engine bay, I go "how the hell did oil get in here", immediately followed by "ah, yeah..."

So yes, it tends to splatter.

grogi

CJhaughey wrote: »

Your engine is an air pump, if you have 4 big pistons going up and down and each one displacing 750cc then there will of course be pressure in the crankcase, pulling the dipsticks on most running engines will result in the same thing happening.

The problem with that explanation is that when one piston goes up, another one goes down... If you sum up, the overall volume of crankcase remains constant and there should be no pressure buildup only because the pistons movement.

jimgoose

CJhaughey wrote: »

Your engine is an air pump, if you have 4 big pistons going up and down and each one displacing 750cc then there will of course be pressure in the crankcase, pulling the dipsticks on most running engines will result in the same thing happening.
High performance engines have special pumps to evacuate the air from the crankcase to minimise pumping losses but The 1KD engine is not in that camp.

In short what you experienced is normal and nothing to worry about, your friend is talking through their hat and should not be listened to.

Strictly speaking, crankcase pressure is caused by blow-by from combustion and isn't supposed to happen. In practice, a certain amount of it - usually around 1 PSI - does happen and hence the need for PCV setups. Excessive pressure down there can be indicative of problems, mind.

Seweryn

Here is a simple cap test on a different engine. There is too much pressure in the crankcase. The cap should stay still or barely move, but that one got too excited and was dancing on top of the engine.

https://www.youtube.com/watch?v=oghhMfXmhDs

CJhaughey

grogi wrote: »

The problem with that explanation is that when one piston goes up, another one goes down... If you sum up, the overall volume of crankcase remains constant and there should be no pressure buildup only because the pistons movement.

This is theoretically true but the pressure differences inside the engine are in the form of pressure waves and as you know waves move in different directions as they encounter solid materials.
Thus while the actual volume remains constant the high speed movement of the pistons is like a hand moving rapidly past your face you will feel the pressure wave as it passes even though the rooms air volume hasn't changed.

i57dwun4yb1pt8

GIGGIDY