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MG MGB Technical - can't drain the oil

hi
79 mgb

oil won't drain

went to chainge the oil, removed the drain plug under the car but only about a quart of oil drained out ? !!
ran the engine a bit hoping to start the flow,no luck.
the dipstick says that it is a bit over filled.

so, what could be clogged up ??

help, please.

incidentally, i had driven from illinois to
washington,d.c., with no problems/trouble.

john
john sutter

You haven't drained the gearbox, by any chance?
Dave O'Neill 2

The transmission holds about a quart of engine oil. Have you checked the oil level in the transmission since you worked on the car? -G.
Glenn G

Have you poked anything inside the drain hole to make sure some piece of debris hasn't covered it? Perhaps your oil level was very low because you have the wrong dipstick. Best to go by putting in the correct amount then seeing where it comes on the dipstick. My glovebox handbook says:

18GG, GD (no oil cooler) 7.75 Imperial pints (4.26 litres, 9 US pints)
18GG, GD with oil cooler 8.25 Imperial pints (4.5 litres, 9.6 US pints)
18V engines (no oil cooler) 5.25 Imperial pints (3 litres, 6.3 US pints)
18V with oil cooler 6 Imperial pints (3.4 litres, 7.25 US pints)

Don't know about only a US quart (pretty close to a litre) in the gearbox, the books say the 3-synch gearbox takes 4.5 Imperial pints, 2.56 litres, 5.6 US pints and the 3-synch gearbox plus OD takes 5.33 Imperial pints, 3.36 litres, 6 US pints. The 4-synch gearbox takes 5.25 Imperial pints, 3 litres, 7 US pints and the 4-synch gearbox and OD takes 6 Imperial pints, 3.4 litres, 7 US pints i.e. 2 or 3 times more.
PaulH Solihull

hi again 79mgb

you guys are confusing me

there is no drain for the gear box, at least not that i know.

the drain at the bottom of thw sump is the one in question. when opened, only about a quart of oil drained, yet the dipstick says there is still oil present. if the dipstick is either too long or too short i shouldn't see any oil if it was draining completely.

i probed into the drain hole for debris, none.
i would love to drain completely and start all over but, but it won't drain completely.

i removed the oil filter , temporarily, and ran the engine, oil poured out on the ground, lost about a half to a quart.

so, i have oil but it wont drain and i can't seem to find a clog of any sort.

if i were to apply air pressure to clean things out ,where might i attach the hose ?

i will keep checking for new information to send you.

any help really appreciated !

john

john sutter

very curious John!
How far in and with what did you probe? With the sump plug removed you should have a big puddle! If the pump is lifting oil with the filter removed, drop the sump pan and give everything a good clean.
Using air pressure is an option but you would need to block all the possible exit points except one eg rocker cover, breathers etc. Use the dip stick hole to get the air in, leave the drain bung off and make sure you have a very wide dish to the catch the oil or it will go everywhere!!


regards


M McAndrew

John,
Did you remove the oil filler cap when trying to drain?
If the breathers are blocked then the oil flow from the drain plug can slow to a trickle as there is no way for air to get in, especially if there is a seal on the dipstick.

As to the question of the gearbox, a look at the oil which drained out will answer this. If it was black and smelt used, it came from the engine; if it appeared fresh it was from the gearbox.

David

David Overington

How long have you owned the car? Have you drained the oil before?

Did the drain plug come straight down, or out sideways?
Dave O'Neill 2

Excuse me if the following question sound like condescending, it is not intended that way. When you checked the oil in the sump, did you pull the dip stick, wipe it dry, insert it back into the engine, pull it back out and see where the oil level is? Not wiping the dip stick is a sure way to get an incorrect reading. Cheers - Dave
David DuBois

There would have to be a huge chunk of something in the sump to stop it draining...............never in my experience has this happened!!!!
There IS a drain plug on the gearbox, directly underneath, a BSP taper plug as I remember, i.e., no washer. The sump plug, on the other hand, is parallel threaded with a compressable copper washer.
Allan Reeling

I'm convinced you have drained the gearbox.
Mike Howlett

There is no way you could drain some oil out of the sump but not all, short of a piece of something blocking the hole which was a flying stab in the dark as I've never heard of it happening either. Did the dipstick show the same level of oil both before and after you drained whatever you drained? If so you definitely drained the gearbox! The drain plug on the gearbox sticks out like the proverbials on a bulldog - literally (straight down from the casting), although the engine sump drain plug is hardly shy and retiring, in the pressed steel sump further forward.

This *is* an MGB we are talking about, I assume ...
PaulH Solihull

not forgetting to check the breather pipes aren't blocked up and to remove the oil filler cap whilst draining

you would help yourself so much if you purchased a Drivers Handbook or this DVD with loads of info on it - http://www.motoringclassics.co.uk/mgb-and-mgb-gt%3Cbr-%3E1974-to-1980/p21730
N Atkins

There's a Nor'easter blowing in your sump
from the drain plug pushing all the oil towards the dipstick? :>)
(Sorry I just had to)

It must be the gearbox that was inadvertantly drained.
You'll want to make sure you refill the gearbox after this. You should look into purchasing a workshop manual. The Haynes manual is very good. In the Colonies it is like the sacred book of MGB maintenance and repair.

Good Luck,
Ralph
Ralph

What colour was the oil? Gearbox should be quite clean.
Art Pearse

Whilst removing the oil filler cap does speed draining a little there is no way *not* removing it will prevent the oil draining out, even if the breather is blocked as well, unless perhaps you have freezing cold grease in there. I reckon it must have been done with the car near the equator and facing south ...
PaulH Solihull

those were tips in addition not as the solution

I'm sure John, like myself, not being mechanical will find the owners Handbook much more appropriate to use for servicing ang and ownership

rather than the repair basis of the never so good for non-technicals Haynes manuals

the wookshop manual is better but the owners Handbook is the one to start with

or get the lot on DVD - http://www.motoringclassics.co.uk/heritage-range/c380
N Atkins

Start the engine and check the oil pressure!!!
Art Pearse

How about sucking the oil out with one of those oil suck out probes? Using the drain plug is yesterday's technology.

PS: Check the gearbox oil level though.
Mike

Are you jacking the car up to undo the plug? even a slight angle will leave a lot of oil in the sump.
c cummins

Why dont you put the sump plug back in, add 5 litres of cheap oil to the engine, see if the dip stick level goes up, then drain the engine again and see if you get 5 litres back out. Tell us what happens.
Mike (just visiting from the MGA forum)
Mike Ellsmore

I thought a suction probe in the dipstick hole was old technology, discredited years ago as it was found to leave debris behind unlike the much greater rush of hot oil out of the drain plug.

The drain plug should be at the back of the sump, jacking up (or preferably driving up on ramps) is not going to leave any oil in the sump, and possibly less than if the bottom of the sump is horizontal.

"Start the engine and check the oil pressure!!!" Now that's just cruel ...
PaulH Solihull

C Cummins might be on to something. Maybe the car is jacked up from the rear end, and the oil has run to the front of the sump!!

Ralph
Ralph


hi
it's john with the 79mgb again

i haven't been able to check out all the suggestions that you gave, i'm 81 years old so it takes i bit of time.
this is my second mgb, before that a couple of big healeys, but i freely admit a am no mechanic !!

so, give me a little time to check out your help bits and i will get back to you all when i need more hints or the problem has been solved.

john
john sutter

To clarify a few items: the drain for the engine is on the passenger's side of the car, at the rear of the engine, and is mounted at a 45 degree angle in the oil pan. The transmission drain is mounted vertically in almost the center of the car. The transmission drain is a tapered pipe plug, while the engine oil drain plug has fine threads and a sealing washer under its head. Hope this helps. And remember, you get wiser with age, no matter what anyone tries to tell you. RAY
rjm RAY

Two posts, two pics.

This one sump drain plug, right hand side toward rear of sump.

Roger T

Second, gear box drain plug on underside of box - note gearbox side plate on left hand side of box. This is a side fill box from a car around 74 I think.

Roger T

"the drain for the engine is on the passenger's side of the car"

Or more universally, the right-hand side ...

Rubber bumper cars had the level/filler plug also on the right-hand side. Chrome bumper used a dipstick, accessed from inside the car, top of the tunnel, right at the front, also right-hand side.
PaulH Solihull

>>Or more universally, the right-hand side ...<< that's if you know the convention - of looking at the car from the rear

(logic would have you looking at the car from the front, looking towards the bonnet/hood and windscreen)
N Atkins

"(logic would have you looking at the car from the front, looking towards the bonnet/hood and windscreen)"

That would be like someone facing you and identifying your left eye when it is really your right eye.
Steven 67GT

N Atkins,

Unless otherwise specified (which is rare), right and left are always determined from your position when sitting in the car looking out the windshield.

Charley
C R Huff

Charley, Steven - this is exactly why I made comment on what Paul put to highlight possible confusion for those that don't know the convention

Paul is extremely knowledgeable on Bs but both he and I are in the UK and yourselves and John (the OP) are in the USA so may have different conventions, like driving on the other side of the road (pavement? - which is for pedistrians here)

unless I've completely confused myself - which is possible

over here things are looked at from the rear of the car looking forward (as Charley put) hence we have RHD vehicles (to us)

things on the left are nearside (near the kerbsones) and on the right offside nearest the centre of the road

Steven - my wife says it makes more sense to be standing at the front of the car looking back when describing things and as I can never beat her logic I agree

Sorry I didn't mean to confuse things just to make sure it was clear for John - not my bits, the previous bits, oh, I'd better stop and leave it to Prop

cheers, Nigel
N Atkins


"Steven - my wife says it makes more sense to be standing at the front of the car looking back when describing things and as I can never beat her logic I agree"

Nigel, agreeing with the wife is the best convention on either side of the pond :)
Steven 67GT

Actually the talk of wives confuses things further for me; I know of a marriage where the wife, even as a passenger, can be very much in the drivers' seat....
Willem vd Veer

Nigel,

Sorry to be repeating what you had already said. I mistook your entire first line as the quote from the previous post.

Also, thanks for explaining nearside and offside. I had always meant to ask for an explanation, but never got around to it.

John, when you get back to work on your car, do check the transmission oil level. Pulling the wrong plug seems to be the most likely explanation.

Charley
C R Huff

Charley, no problem, cheers, my posts are not always the easiest or most accurate usually, but not always, because of my typo mistakes

I'm with you and others and thinking maybe John has drained the gearbox so he certainly wants to check before driving but it's no bad thing to change the gearbox oil

I'm sure a copy of the owners Handbook (see previous post for DVDor better still buy a papercopy) would help John enomously

I wonder what USA visitors here think of the advice to walk on the pavements!
N Atkins

"my wife says it makes more sense to be standing at the front of the car looking back when describing things"

That's probably why wimmin don't know their left from their right ...
PaulH Solihull

at the moment I think she wants me in front of the car - as soon as I'm let out the doghouse

quite often my wife's logic is good common sense but other times, well, I'm just stunned by it
N Atkins

Some modes of transport uses "Port" and "Starboard"
(saves any confusion)
R Fowler

Or "bow side' and "stroke side"
Art Pearse


hi 79mgb

success, at last

you guys were correct, i could'nt see, find, remember that there are two drain plugs.
all is o.k., except that i feel like an idiot.
thanks again, and until next time.

john





john sutter

When having mg difficulties my wife says 'would'nt it be better to get a proper mechanic...' I reply 'that's not the point...!'
And that IS the point John S. I bought my first mgb last rear - no experience what so ever.
Learning by doing is the motto...and asking for help when needed... :)
/Moss
Moss

Well, John, we are all idiots, just on different subjects.

Charley
C R Huff

Good Lord John, I hope I can get under an MGB to change the oil and make a mistake when I am 81!

Tony
Tony Oliver

Amen to that Tony!

Thanks for the feedback John. I agree that we are all idiots, there are a number of threads on this BBS that describe our mistakes.
Willem vd Veer

This thread was discussed between 27/05/2011 and 06/06/2011

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