Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Dipstick wrong length?

hi everyone, a while back i posted about a breather problem, in that it would spurt oil all over my engine bay at high revs. I thought i fixed it but it has done it again, but looking closer when i did an oil change i noticed that i put an aweful lot of oil in the engine before i got to the correct level on my dipstick. my dipstick is an aftermarket aluminium one as my engine didnt come with one. does anyone know the correct length for the dipstick as i now believe i may be putting in too much oil. the amount i put in was over 4 litres.
A P New

Just done oil change, so good timing!

Dipstick is 283 mm from tip to collar (where it sits in the dipstick tube) Min mark is 36mm from end and max is 45mm from end. Mine is original style-maybe original!

I put in about 4 litres and then top it to the max on the dipstick. So your 4+ litres looks about right. Haynes says 4.26L for sump + 0.57L for filter. Can't see the cooler making any difference as I doubt it ever empties when you drain the oil

I did hear of after market ones where the collar was poorly secured. HTH M
Michael Beswick

This has cropped up a number of times, and I'm sure I've read there were different dipsticks for different years. The wrong one will give the wrong oil level. There is also the theory that late 18V engines had lower capacity sumps! Whilst my V8 takes a full 5L for an oil and filter change to get back to F on the dip-stick, the roadster (73, 18V582) probably only takes 4 and a bit. Haynes is probably a dry engine, as is the Workshop Manual.
PaulH Solihull

Check out British Automotive at
The article on MGB dipsticks & tubes for the different
engines is very good.
Joe G
J. E. Guthrie

Indeed, tubes as well. The shorter tube with the same dipstick was probably used when the sump *quantity* (not the sump itself) changed to the later quantity in late 71.
PaulH Solihull

Indeed, this topic crops up again - I'm still worried about whether I've put too much oil in (4.5 litres - 1.8 engine 1977 model, no oil cooler). When I did my first oil change only 2.5 litres came out - despite mark on dipstick showing 'max'. My problem is that I cannot identify engine number yet as stamp on block is replaced by 'ivor searle' own stamp. There is an original code behind the starter motor at the bottom of the block right hand side, but I cannot read it until I take the engine out next week.

Any other ways of telling which engine one has?

Each of the 4 (4 cyl oil cooler) engines I've had experience of has needed 4+ litres at a change, as per the book. 2.5 would make me worry.


I still feel you may have a high rpm blow by problem as we discussed last year, you could always physically see what happens by holding a high rpm load on a rolling road.

P Burgess

This thread was discussed between 25/09/2010 and 27/09/2010

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.