• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

BMC A-series: Oil in coolant

Ladybug

Freshman Member
Country flag
Offline
(Non-native speaker, my apologies for any errors)

The 948 cc A-series engine on my Austin a35 (completely rebuilt a couple of years ago) is leaking quite a bit of oil in to the coolant. No sign of leakage occurring the other way tho. I've only been able to find detailed instructions on trouble-shooting and fixing the issue on BMC's C-series engines.

Any advice or links on the matter are greatly appreciated 🚗
 

Madflyer

Jedi Knight
Country flag
Online
Look at it this way higher pressure wins. your coolant pressure is between 9 and 12 pounds from Radiator cap, Right.
Your motor cyl. pressure at near new is over 100 pounds so it is pushing the block pressure to water jacket. Retorque head in the right order twice hot and cold. I would not think crack block but head gasket, there are a few spots where the material is thin between cyl and water jacket that would be the worse case. MF
 

Pat MM

Freshman Member
Country flag
Offline
The 948 is the same engine used in the Morris Minor and the Sprites and Midgets. There is a huge amount of information available online. It is always worth a try retorquing it, but if that doesn’t fix it, you will be removing the head.
Since the engine has been apart in the past, the head studs may need to be replaced and your head needs to be checked to make sure that it is flat.

Good luck getting it repaired.

I really miss my A35 van, but had to sell it and my ‘67 Cooper S to pay for childcare when I was in school. At least I was able to keep the Sprite!
 
OP
L

Ladybug

Freshman Member
Country flag
Offline
Thank you both. I did notice this was a frequent topic on MG forums, but wasn't aware that midget had the same engine.
 

Madflyer

Jedi Knight
Country flag
Online
The above is correct as to head studs a small cost but smart money tighten more than three times that you know of. Only a light dressing of head is needed to make sure it is flat and true. and yes used on many cars. MF Where is Tampere
 
OP
L

Ladybug

Freshman Member
Country flag
Offline
Where is Tampere
Finland :smile:

After retorque and thoroughly rinsing the radiator, there seems to be much less oil. We'll be taking the engine out and reassembling anyway come winter. Might not be worth the effort tho - seems to be more of a feature than a flaw 😁
 

Madflyer

Jedi Knight
Country flag
Online
These motors are built for wear and tare and worth the rebuild. And yes they leak, a good look and inspection and careful reassemble will bee good for many years. This Forum as a guide as a tool also. MF
 
Similar threads
Thread starter Title Forum Replies Date
K BMC Supplemental Tool Kit Bags - Reproductions made anywhere? Austin Healey 8
O For Sale BMC Service Shop sign Other British Classifieds 3
B orginal BMC radio Austin Healey 9
C BMC Special Tuning Data Austin Healey 9
K MGA BMC paint colour code AL1 MG 2
K BMC paint colour code AL1 [wire wheels] Austin Healey 1
HealeyRick The BMC Story Spridgets 7
HealeyRick The BMC Story Austin Healey 29
HealeyRick "Tuning BMC Sports Cars" Spridgets 11
abarth69 Dry Sump BMC Engine Spridgets 3
I Resource for BMC/Leyland parts for Sprites? Spridgets 15
S Argentinian BMC Ute?? Other British Cars 4
B 100/6 BMC parts manual Austin Healey 12
K Colour Chart for Austin-BMC-MG...Jaguar? Triumph 3
sjuengst BMC affinity Austin Healey 0
theleisure BMC SPECIAL TUNING DATA Manual Spridgets 4
B BMC Training Unit Bus Other British Cars 164
BugEyeBear 1958 BugEye 1st Road Test Vintage BMC Video Spridgets 0
E Tip to remove the BMC on a '70 Midget Spridgets 6
TurnerSports222 Alexander Cross Flow Head - BMC Other British Cars 4
Luke_Healey Was this seat belt a real BMC part? Spridgets 3
H 1965 BMC AM Radio - no sound Austin Healey 5
John Loftus BMC fastener codes Restoration & Tools 10
Howard_The_Duck Posi-Ground BMC radio MG 5
B BMC Comps Dept new book Austin Healey 0
M Crosley with BMC engine-trying to identify it. Other British Cars 6
S BMC registry Austin Healey 12
rovernut Austin or BMC mini logo British Motor Corp 4
78Z check out this BMC/BL history site Other British Cars 3
M Series 3 E-Type Bonnet Jaguar Classifieds 0
6 For sale 1966 Series 1 FHC $85,000.00 Jaguar Classifieds 0
ROARRR Series 2 XJ6 with cert for chev eng for parts or refurb Jaguar Classifieds 0
N Wanted Spats - XK Series? Jaguar Classifieds 4
S Series 1/2 Wiper Motor Needed Rover / Land Rover 0
steveg HS vs HD series carbs Austin Healey 2
W XJ6 Series I bumper swap to Series II Jaguar 0
S For Sale Mg t-series crankshaft tb tc td tf 1250 1500 MG Classifieds 0
D Source for XJ6c Series ll Ignition key blanks & remote Jaguar 1
Lin Fairly new YouTube series on AH100 restoration Austin Healey 0
H Lotus Super 7 series 2 Race car for sale Lotus 0
T For Sale Gear reduction starter fits jaguar 3.8 340 mark series 3.8l 3.4l - $100 Jaguar Classifieds 0
steveg HD series Jet Centering - a Caution Austin Healey 19
M E-type series 1 plastic dash vents Jaguar 1
M XKE Coupe series 1 Tub versus series 1.5 Jaguar 1
O Wanted Vauxhall Victor F series parts Other British Classifieds 2
O TR6 TR series transmission compatibility Triumph 4
B For Sale 1969 Jaguar XKE 4.2L Series II Coupe - Indiana Jaguar Classifieds 0
Basil About to re-install my fuel tank Series I E-Type Jaguar 6
Healey Nut "Father Brown" British television series Austin Healey 9
Basil Series 1 EType Spotted 2

Similar threads

Top