Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 22nd August 2015, 20:48   #1
gazcon
Avid contributor
 
Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec"

Join Date: Sep 2010
Location: Norfolk
Posts: 226
Thanks: 111
Thanked 28 Times in 24 Posts
Default Diesel oil change - missing oil

I've done a few oil changes now on my 75 diesel and the Mrs' Zt diesel. Each time I've been some way short of getting the stated full 6.75 litres to drain out.

Changed the oil on the Zt today and only a bit over 5 litres came out, which means there must still be a litre and a half still in the system somewhere.

I change the filter every time, so it's not in there! I have the car up on axel stands, which if anything I would have thought would help drain the engine... Oil level around the half way mark on the dipstick so it wasn't low to start with...


Any tips on what I'm doing wrong?
gazcon is offline   Reply With Quote
Old 22nd August 2015, 20:58   #2
trikey
Premium Trader
 
trikey's Avatar
 
Rover 75

Join Date: Nov 2010
Location: Devon
Posts: 33,714
Thanks: 8,837
Thanked 14,831 Times in 8,030 Posts
Default

Did you check the level on the dipstick before you removed the sump plug?

Oops just read your full post, if its only halfway, theres the answer!
__________________
Lest we forget..
trikey is offline   Reply With Quote
Old 22nd August 2015, 21:07   #3
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
Default

And some stays in the oil cooler and in a hundred nooks and crannies and shallow pools. The add by volume basis is pretty variable and is really just a guide. The dipstick Min/Max is definitive even though it isn't calibrated by volume.

TC
T-Cut is offline   Reply With Quote
Old 22nd August 2015, 21:22   #4
gazcon
Avid contributor
 
Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec"

Join Date: Sep 2010
Location: Norfolk
Posts: 226
Thanks: 111
Thanked 28 Times in 24 Posts
Default

Thanks guys.

Yes, the dipstick was at around the halfway mark before starting, so I guess that's about 0.5 litres worth, and the rest is stuck in the oil cooler etc. That makes sense.

Being a bit of an enthusiastic novice with these things, I'm always reluctant to rule out the possibility that I've done something stupid
gazcon is offline   Reply With Quote
Old 23rd August 2015, 22:38   #5
tourer
Posted a thing or two
 
Rover 75 Tourer CDT Auto.

Join Date: Oct 2011
Location: Long Eaton
Posts: 1,341
Thanks: 30
Thanked 220 Times in 160 Posts
Default

I always use a Pela and it always manages to suck out 6.5 ltrs, but that is from dipstick showing full as car uses none between changes. Car also on the level as it does not need to be in the air with a Pela.
tourer is offline   Reply With Quote
Old 24th August 2015, 00:28   #6
bassman
Avid contributor
 
Rover 75 CDT Connoisseur SE Saloon (Manual)with XPower Upgrade

Join Date: Mar 2011
Location: Durham Area
Posts: 105
Thanks: 10
Thanked 5 Times in 4 Posts
Default

Quote:
Originally Posted by gazcon View Post
Thanks guys.

Yes, the dipstick was at around the halfway mark before starting, so I guess that's about 0.5 litres worth, and the rest is stuck in the oil cooler etc. That makes sense.

Being a bit of an enthusiastic novice with these things, I'm always reluctant to rule out the possibility that I've done something stupid

Using that working out though...you are still only removing 5.5 litres...I use an electrical suction pump, and mine always sucks out between 6.25 and 6.5 litres, and the same amount of oil should stay in the cooler and the nooks and crannies as does in yours......
__________________
Half of the people can be part right all of the time, Some of the people can be all right part of the time.
But all of the people can't be all right all of the time. .........I think Abraham Lincoln said that.
"I'll let you be in my dream if I can be in yours" I said that............................ Bob Dylan 1963
bassman is offline   Reply With Quote
Old 24th August 2015, 16:00   #7
gazcon
Avid contributor
 
Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec"

Join Date: Sep 2010
Location: Norfolk
Posts: 226
Thanks: 111
Thanked 28 Times in 24 Posts
Default

Perhaps the Pela method is more effective at getting all the old oil out... presumably the suction pipe goes straight down the dipstick tube into the sump though, so unless there's some funny obstruction between there and the sump plug...

I always refill to half way between min and max on the dipstick, as I'm equally worried about over filling as under filling So that's 0.5 litres accounted for, but I'm still about a litre short, and can't see the oil cooler holding that much (?). Strange.

Might try dropping the car while it's draining next time and see if an extra 0.5 - 1 litres are suddenly released from somewhere.

I change the oil every 7,000 miles-ish, so it's not the end of the world. If I stuck to the recommended 15k schedule I'd have a litre or so of oil in there that had done 30k miles!

Same on both my 75 & ZT. Can anyone who drains the oil via the sump plug confirm that they get 6+ litres out?
gazcon is offline   Reply With Quote
Old 24th August 2015, 16:16   #8
gazcon
Avid contributor
 
Rover 75 2004 Cdti Contemporary & a 1999 V6 "jap spec"

Join Date: Sep 2010
Location: Norfolk
Posts: 226
Thanks: 111
Thanked 28 Times in 24 Posts
Default

OK so looking at this...


...it would seem that the dipstick pipe, and therefore the Pela suction hose, would go right to the bottom of the sump. With no need to jack the car up, would that result in getting more oil out of a level sump?


Looking at this...


...the internals of the sump are more complex than I expected, and there seems potential for trapping at least some oil there. Although as the car is jacked up from the front (on 2 axle stands for the record), and the sump plug is at the rear of the sump, I would have thought having the car raised would aid draining if anything....


I hasten to add that I have not just gone out and disassembled my sump! I'm curious about the missing oil, but not that curious!
gazcon is offline   Reply With Quote
Old 24th August 2015, 18:36   #9
first-things-first
Posted a thing or two
 
first-things-first's Avatar
 
MG ZT

Join Date: Jul 2014
Location: Hornchurch
Posts: 1,255
Thanks: 176
Thanked 352 Times in 272 Posts
Default

+1 for the Pela type method and volume.

I got around 6.4 litres by suction and then (just out of curiosity) I got about 100 ml of dribbles from the sump plug.

All on level ground.
first-things-first is offline   Reply With Quote
Old 24th August 2015, 21:07   #10
bassman
Avid contributor
 
Rover 75 CDT Connoisseur SE Saloon (Manual)with XPower Upgrade

Join Date: Mar 2011
Location: Durham Area
Posts: 105
Thanks: 10
Thanked 5 Times in 4 Posts
Default

Quote:
Originally Posted by gazcon View Post
OK so looking at this...

...the internals of the sump are more complex than I expected, and there seems potential for trapping at least some oil there.
Yes a lot more intricate than I thought as well.....As well as trapping oil............I can now see where my suction pipe possibly got "trapped" and (after a bit of force) ended up coming out 6 inches shorter than it went in......This was 30k miles and 4 oil changes ago.....so its presence hasn't done any damage, (touch wood)...
__________________
Half of the people can be part right all of the time, Some of the people can be all right part of the time.
But all of the people can't be all right all of the time. .........I think Abraham Lincoln said that.
"I'll let you be in my dream if I can be in yours" I said that............................ Bob Dylan 1963
bassman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 15:31.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd