Weird DIP STICK readings on CDTi

Edward Huggins · 9th March 2016, 11:07

I find that when I take a reading when cold, I can see no oil at at all on the dip stick - it's perfectly dry and suggests that the oil is at a very low level.

However, when I dip it (just once more) again it shows over the Maximum fill.....

Does this mean I have been continually over-filling the engine due to this "False" reading?

Why does it do this?

ED

stevestrat · 9th March 2016, 11:17

With a diesel the manual actually states to remove the dipstick, wipe it then slowly reinsert.

1. Withdraw the dipstick and wipe the blade clean.
2. Slowly insert the dipstick and withdraw again to check
the level, which should NEVER be allowed to fall below
the lower mark on the dipstick.

Edward Huggins · 9th March 2016, 11:44

Quote:

Originally Posted by stevestrat

With a diesel the manual actually states to remove the dipstick, wipe it then slowly reinsert.

1. Withdraw the dipstick and wipe the blade clean.
2. Slowly insert the dipstick and withdraw again to check
the level, which should NEVER be allowed to fall below
the lower mark on the dipstick.

Thankyou, but the point I am making is that the dipstick is perfectly clean when first removed. No need to wipe it over as there's no oil on it! On the second insertion it shows "overfull". ED

Dorset Bob · 9th March 2016, 12:19

If the second dip says overfull, then it is.

As Stevestrat says, the procedure is that the reading (if any) on the first removal should be ignored.

When I had a diesel 75 it scared the life out me when I first removed the dipstick as, like yours, there was no reading.

Mickyboy · 9th March 2016, 14:16

If it shows too much on second dip, then it's overfilled mate, a plea pump will make it a easy job

Edward Huggins · 9th March 2016, 15:43

Quote:

Originally Posted by Dorset Bob

If the second dip says overfull, then it is.

As Stevestrat says, the procedure is that the reading (if any) on the first removal should be ignored.

When I had a diesel 75 it scared the life out me when I first removed the dipstick as, like yours, there was no reading.

Many thanks for this very re-assuring reply! Does anyone know what causes this strange effect? Edward

T-Cut · 9th March 2016, 15:48

Quote:

Originally Posted by Edward Huggins

Does anyone know what causes this strange effect?

Air pressure in the guide tube prevents oil from rising up it after shut down. The upper end is sealed by the dipstick handle so the oil can't displace the trapped air so the level in the tube stays at the end.

TC

tourer · 9th March 2016, 19:49

Quote:

Originally Posted by Mickyboy

If it shows too much on second dip, then it's overfilled mate, a plea pump will make it a easy job

And a Pela pump will even make it easier than that.

Edward Huggins · 10th March 2016, 08:01

Quote:

Originally Posted by T-Cut

Air pressure in the guide tube prevents oil from rising up it after shut down. The upper end is sealed by the dipstick handle so the oil can't displace the trapped air so the level in the tube stays at the end.

TC

Many, many thanks - that makes good sense. I bet I'm not the first to be fooled by this! ED

Mike Noc · 11th March 2016, 07:11

If the PCV valve sticks open you can get the opposite effect - sump appears overfilled until you take the second dip.

9th March 2016, 11:07	#1
Edward Huggins Avid contributor Rover 75 Join Date: Aug 2015 Location: Southwold Posts: 130 Thanks: 15 Thanked 8 Times in 8 Posts	Weird DIP STICK readings on CDTi I find that when I take a reading when cold, I can see no oil at at all on the dip stick - it's perfectly dry and suggests that the oil is at a very low level. However, when I dip it (just once more) again it shows over the Maximum fill..... Does this mean I have been continually over-filling the engine due to this "False" reading? Why does it do this? ED

9th March 2016, 11:17	#2
stevestrat This is my second home ZT260 #243 (resting) Join Date: May 2010 Location: Prestonpans Posts: 22,455 Thanks: 650 Thanked 4,624 Times in 3,358 Posts	With a diesel the manual actually states to remove the dipstick, wipe it then slowly reinsert. 1. Withdraw the dipstick and wipe the blade clean. 2. Slowly insert the dipstick and withdraw again to check the level, which should NEVER be allowed to fall below the lower mark on the dipstick. __________________ Steve T4 Location Map

9th March 2016, 12:19	#4
Dorset Bob Senior Citizen Rover 75 2.5 Connoisseur SE,Chrysler 300C,124 Spider, Daytona 955i,Honda XL250 & Royal Enfield 650GT Join Date: Feb 2008 Location: The Kingdom of Wessex Posts: 6,976 Thanks: 2,391 Thanked 2,685 Times in 1,686 Posts	If the second dip says overfull, then it is. As Stevestrat says, the procedure is that the reading (if any) on the first removal should be ignored. When I had a diesel 75 it scared the life out me when I first removed the dipstick as, like yours, there was no reading. __________________ Let the good times roll............

9th March 2016, 14:16	#5
Mickyboy SERVICING AND DEALER DIAGNOSTICS MG ZT CDTI 135 + & MGZT CDTI AUTO 160 & ROVER 75 TOURER CDTI 160 TROPHY YELLOW Join Date: Aug 2013 Location: Hernebay Posts: 4,331 Thanks: 818 Thanked 2,414 Times in 1,141 Posts	If it shows too much on second dip, then it's overfilled mate, a plea pump will make it a easy job __________________ [SIGPIC][/SIGPIC] T4 Owner Jobs done : new UBP, Spy hole mod, Rear hub(wheel bearing),plenum cleaned and emptied, Inline thermostat fitted,Full service, In car Digital tv/DVD Bluetooth Satnav etc, Replaced UBP, Restored headlights,Fixed airbag connection.replaced HP pump,replaced rear light seals,changed intercooler O rings. Jobs to do: ,replace drivers lock,.[/SIZE]

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11th March 2016, 07:11	#10
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	If the PCV valve sticks open you can get the opposite effect - sump appears overfilled until you take the second dip.