Forum:
Hello again,
Thought I would run this one past you guys, as you seem to know all there is to know about Daihatsu's. Anywho...
My F300 Rocky/Sportrak has an HD-E 1600 Petrol.
Over a period of about a month I will lose about a litre of oil from the sump. In this time I will have travelled about 500-700 kilometres. I do use my Rocky offroad at regular intervals, and do some long distance driving of about 200 kilometres/120(ish) miles.
I don't really think it is burning it, as there is never any visible smoke, ever. There is noticeable "piston slap" when started cold until the motor gets warm. It has always done this, and I just drive her nicely until she quietens down. Is it at all possible that when cold and this piston slap is happening (which is caused by "sloppy" fitting pistons, then when they heat up and expand they are fine) that oil is getting up past the rings and burning?
Why no smoke?
She is always looked after and oil/filter changed every 5000 kilometres. Got me puzzled.
Mace? OldMiniMan? BundyRumandCoke? Help!
Slapper
Your suggestion is entirely feasible, however, the engine in your vehicle is a Toyota unit, these run quite hot, slowly burning amounts of oil would not necessarily be evident until the problem was quite severe when compared to other cooler running engines of the same period.
Is there no sign of leakage anywhere, the usual places are oil filters, sump plugs and rocker cover gaskets, these would not necessarily show themselves as small amounts would be expelled.
If you suspect the rings, do a compression test on the engine, this would identify worn piston rings, worn valve guides, etc, and give an indication as to the cause of the problem.
Re-ringing the engine is possible without removing the engine as this can be done by removing the sump and accessing them that way, this needs to be done with care, and ensuring the top stepped ring is fitted correctly.
one thing you could do to
one thing you could do to check for small leaks is clean the engine off any oil that you can see then take it for a run to heat up the oil mainly on up hill slopes if possable.This will allow the engine to work a bit harder and put it under more stress so you will find out if there is any leaks.The engine may have a hair line crack in one off the gaskets but may only leak when under stress and when the oil is hot.If so this will not be to expencive to sort.
Losing Oil
Are you mistaking the noise of the hydraulic tappets for piston slap as my 1991 is a bit noisy when cold but doesn't use a drop of oil. Once warm it is very quiet.
You may have a leak which is being picked up by air flow but will be visible if you remove the sump guard. Look for oil traces around the filter base and the sump plug. The plug has a fibre and resin sealing washer which is often not noticed when servicing and tends to remain on the sump and can cause a fine leak. I always ensure this seal is prised off the sump and then either use a replacement of a new copper sealing washer. Oil under pressure will come out often as a fine mist and will consume a good amount of oil.
OLDMINIMAN
M J Young
hmmm...
It is definitely piston slap, as the tappets are all fine,and the noise is not coming from the top of the motor.
There is absolutely no visible leaks anywhere. It's only done 130,000kms, and it is in really good nick. No oil anywhere. Still puzzles me...
Hmmmm
If you are certain that it is piston slap then I assume when you decellerate you can hear them rattle as the pressure is reduced on them. A test would be to watch the rear view mirror which I assume shows no smoke, decellerate and the accelerate. Their should be a good puff of blue smoke as oil is sucked up past the pistons on decelleration and then burnt whoff when you accelrate.
A sure test would be to have a pressure test done on the cylinders to see if they are giving a reduced result or maybe one or two are showing a significant difference.
The rattle from the top could be wear in the cam areas and not just pistion slap.
If you are certain, then the best thing is to remove the head and look at the pistons to detect movement and the bores to detect uneven wear and ridges etc. If you are burning oil your plugs will be blackened and a bit oily and you will fail most emmission test/smoke test. 130,000Kms is not a lot of miles for these engines but it depends entirely how those miles have been racked up. Short journeys to and from the station or the shops do more damage than long motorway journeys. Equally irregular service periods and inferior oils will all add to wear. I often get remarks that a car has low mileage for year but if it has spent most of it's life doing short journeys and rarely getting up to operating temp, then this causes more wear on the engine and is not a reason to buy a car.
OLDMINIMAN
M J Young