MG Car Repair: 1966 MGB GT loss of oil, oil pressure gauge, pressure relief valve

Question
QUESTION: Hi,

I am new to the world of MG ownership but have just been dumped in the deep end. I have recently purchased a 1966 MGB GT. It has had a full body and engine restore some years ago, and has covered only 45000. Today it has dumped a sizeable amount of oil on the driveway but I cannot find any  obvious signs of breakage or leaking points. The only thing I can narrow it down to is possibly a split oil cooler feed pipe (Engine block, not oil filter end), or oil pressure gauge flexi-pipe or possibly the oil pressure relief valve itself. The oil seems to have appeared from around this area. I tried cranking the engine over a turn or two and did not get any oil pressure reading on the gauge. I have now drained the remaining oil and there was approximately 2 litres in the sump. I checked the oil cooler pipes (in and out) and neither had any oil in them. What I need to know is could this all be attributed to a dead oil pump? If so, are they easy to replace and could this also have been the cause of my car vomiting oil?

Any help and advice would be very gratefully received.

With kind regards

Barry

ANSWER: Hi Barry,
I have been working on MGs through the complete life of the MGB and have rebuilt enough MGBs that I can't possibly count them and I never seen a failed MGB oil pump when it had oil in the engine. Even when they have eaten some good sized pieces of trash.

First wash the engine and put oil in it and remove all of the spark plugs and remove the wires off of either side of the coil and use the starter to spin the engine. Watch for any oil leaks and look at the oil pressure gauge. Within a short time you should see about 35 PSI on the gauge. If so, watch for any major oil leaks to see where it is leaking. Then correct the leak.

If you can't get 25 to 35 PSI with the starter don't bother to try to start it as you failed to watch the gauge when it was running and probably damaged the bearings. When you are driving a car and you see the oil pressure gauge go to zero. From that point to when there is major engine damage is measured in seconds. That is why they put a gauge in the car.

The fact that you had a little oil in the pan may mean you caught it in time but you will not know until you do the above test.
Howard

---------- FOLLOW-UP ----------

QUESTION: Hi Howard,

Many thanks for the very quick and informative response. I drained the oil firstly to see how much was left but also to see if there was any debris in it, but it seems fairly clear of any metal filings or trash (good word).

The topping up of oil and inspecting was going to be my next step. Since my previous blog, I have noticed that the steel braiding on the oil pressure gauge pipe is damaged where it has rubbed on the oil cooler pipe union. Is it wishful thinking to think that this pipe has burst due to the braiding having been worn and under pressure, is letting go of its contents hence why there is no reading on the oil pressure gauge?

I'll carry out your recommendations and report back accordingly.

With many thanks and regards

Barry

p.s Just to set the scene a bit more, I wasn't actually driving the car, and it was just ticking over so hopefully that will help towards there not being any damage.

Answer
Ok Barry, let me know what you find. In the dealerships I learned to not try to guess what was wrong and run tests to either show what was wrong or run tests that isolated the problem into a small area. This was true in mechanical, electrical or hydraulic problems. Many times I was surprised what I found but always found the problem. This was necessary as I worked on a commission bases as did most mechanics.

Let me know,
Howard