MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

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 - No Oil Pressure - No Compression



I am "resurecting" a '69B that has been stored (not very well) for about twenty-five years.

I got to the point where it was time to try to start the engine.

The entire driveline had been removed from the car, but it did turn over manually when I tested it. I was pleasantly suprised.

When cranking with the starter now, there is zero oil pressure, and an average of 50lbs. of compression. I removed the oil pressure flex hose, at the firewall and cranked again. Zero oil was emitted from the hose.

I think I already know the answer, but I'll ask anyway: Does anyone have any suggestions, other than engine removal and disassembly?

Thanks in advance.
JR Ross

My guess on the oil pressure is that it needs more cranking (with the plugs out). An engine that has been standing for that length of time will take a while to get the oil pressure up.

The lack of compression is probably due to stuck piston rings and sticky valves.

You may get it going after it's been spun over a few times to free things up a bit but really, the engine needs to be stripped, cleaned and assessed for condition properly.

Mark
M D Howard

Assuming the engine hasn't been run "properly" for 25 years it's a miracle it still turns over. I'm with Mark. If you are going to put a lot of work in to get the car back to driveable condition then an engine and gearbox strip and overhaul would be an excellent idea.

Tony
Tony Oliver

If you really want to start the engine squirt a bit of oil down each cylinder to seal the dry rings and check the compression again (it wont run on less than 70lb comp) if you get compression put an extra gallon of oil in the sump, this will submerge the oil pump and help it prime. Try and start the engine. If you get it going stop it and drain out the extra oil. Or if you even just get oil pressure drain out the extra oil. This wont cause any problems as long as you dont leave the extra oil in with the engine running too long.
Denis
Denis4

JR,
Try the website http://www.mgaguru.com/mgtech/engine/de101b.htm
Barney has several pages dedicated to Starting a Dormant Engine. Lots of good advice there.

Good Luck,
Ralph
Ralph

On both of my "B" 18V rebuilds, I could not get oil pressure by just cranking, but pressure came up the second the engine started...I was prepared to turn the ignition off the instant the engine started, if there was still no pressure....Went immediately to 75lbs....
As mentioned, put some (teaspoon) oil in the cylinders, and recheck the compression.
Edward
E.B. Wesson

I think Peter Says in his book, ( you know whom I am talking about!) Crank without the plugs in on a new engine. It thus cranks faster then when an oil pressure just registers put the plugs back then fire up. While a person was cranking, without the plugs another person could check that sparks were being developed etc. Hate to keep cranking without any joy if the electrics were cock-eyed. Mike
J.M. Doust

Remove the oil cooler hose at the back of the motor & use an oil can to squirt in oil until it is full. That will prime the pump. I presume that with a 69B the oil filter is the stand up cartridge type - notorious for draining out when sitting unused. Get youself the later 1970 spin on type of adaptor and use a new filter.
Garth
Garth Bagnall

This is where the V8 benefits - remove distributor, put drill on oil pump, watch oil pressure come up.
PaulH Solihull

This thread was discussed between 24/08/2011 and 29/08/2011

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now