From Haynes, Diesel oil levels, how do you check yours

[Keith]

A member asked a question at Haynes that I think I have seen mentioned before but can't remember where.

He gets differing readings on his dipstick depending on when he checks the level, and even differing levels if he repeats the same check a few seconds later.

I can't say I have noticed this behavior on my CDT but otoh I only check the level once a month if that, as the car does not use any oil ever, and that is always on level ground with a cold engine normally several hours after it had last been used

Is there a right or wrong way/time/engine temp etc to check the level?

[Simon]

Good ol' Haynes manual says to check oil when engine is cold (or wait 5min after switch off). This is because when the engine is in use, oil is in circulation (obviously) and when you switch off the oil can still remain in the upper engine components (leading to a lower-than-actual reading)

Thermal expansion (albeit, only slight) can be important with hot oil too (not to mention personal injury risks....)

As you suggested at Haynes, sludge could be causing inaccurate readings if the sludge is blocking the pipes, especially in the narrow pipe the dipstick goes in.

[Keith]

Snipped you twos last two posts funny but inapppropriate, you can get off the floor now Simon :)

Anyway I mentioned sludge as a possibility as that could cause higher than real readings but is that a real possibility?

[Simon]

Snipped you twos last two posts funny but inapppropriate, you can get off the floor now Simon :)

Anyway I mentioned sludge as a possibility as that could cause higher than real readings but is that a real possibility?

Quite right about posts, fair enough decision :)

As for sludge.... there would have to be a fair amount in there to cause inaccurate readings. In fact, if there were that much sludge you would start to question when the last oil change was...

What other mechanics are in the derv engines? Y'know, like reservoirs or places where the oil can settle?

[Ti Rich]

Keith

The dipstick appears to have a tight air seal to it. You have to remove the dipstick, clean it, pop it back in and then take a reading.

Not that it uses any oil. I have only put in 0.5L in 55k miles between services.

[maxi_crawf]

Keith

The dipstick appears to have a tight air seal to it. You have to remove the dipstick, clean it, pop it back in and then take a reading.

Not that it uses any oil. I have only put in 0.5L in 55k miles between services.

55K between services :panic:

maxi_crawf

[Ti Rich]

That's not quite what i meant!

I mean from new, apart from oil changes, I have only used 0.5L of oil.

[Paranoid Carlos]

When I take the dipstick out the oil on it smears up the dipstick hole, wipe then reinsert and the reading is always about 4 inches past the top mark.

[Ti Rich]

When I take the dipstick out the oil on it smears up the dipstick hole, wipe then reinsert and the reading is always about 4 inches past the top mark.


Mine doesn't do that, interesting. Or, is your oil over filled?

[Keith]

Thats partly the point of this thread although 4" is a bit extreme I have seen it mentioned elsewhere and the guy at Haynes prompted me to bring the issue up again.

I agree with you Rich I reckon a combination of capillary action and the fact the stick is fairly airtight is causing oil to rise up the pipe on the move

So pull the dipstick, clean it, allow the contents of the tube to settle then check may give a bit more accuracy.

[crofts]

Thats partly the point of this thread although 4" is a bit extreme I have seen it mentioned elsewhere and the guy at Haynes prompted me to bring the issue up again.

I agree with you Rich I reckon a combination of capillary action and the fact the stick is fairly airtight is causing oil to rise up the pipe on the move

So pull the dipstick, clean it, allow the contents of the tube to settle then check may give a bit more accuracy.

Peculiar this one. When I initially pull the dip stick out it is invariably only about 1/4 inch up.
I have often had to dip several times to get the correct level/line. Maybe initially there is oil in the pipe which drains when open to air. A short while later I dip and remove quickly and get a true clean line.
It nearly caught me out the first time & I was about to add a couple of litres but knew instinctively that my car dosn't use oil. :)
If the oil is genuinely high up I would suggest excess is removed urgently before damage occurs, not least to the clutch in manual cars. ( Another good use for a Pela vacuum pump..... as well as for oil changes. Of interest I looked at the handbook for my daughters Peugeot 205 diesel tonight which actually reccomends oil changes by suction !)

[windrush]

I always check my oil first thing in the morning after the car has stood in the garage all night before start up The level is allways low on first removale of the dip stick the next after a wipe is spot on mind you my milage has not yet reack 12,000miles

[Paranoid Carlos]

6.8 litres exactly, added with a jug, and measured with a jug when it comes out.
Doesn't use a drop. But I change mine every 6 months anyway so it does't really get a chance!!!!

Now I'm walking to work it's going to be every year,because I will only be doing about 5'000 miles a year:D :D :D

[Livermpj]

I'm glad it's not just me, then! :confused:

CDT engine: Dipstick cap is a tight fit in the tube and sealed by O-rings.

1st removal of dipstick and it's usually squeaky clean. Re-insert and remove again and the level is OK....

I'm amazed at how oil-tight the engine is, the entire outside is bone dry. It uses a tiny amount between changes (10W/40 semi synthetic).

Pete.