Just been on long journey with my 1983 Bedford TL horsebox. What I thought was the brake air pressure warning light and buzzer came on and off sporadically on the journey home. The brakes were absolutely fine so I ignored it. It wasn't till I was about a mile away from home that I realised that it was the oil pressure warning light!!! We had had a problem with oil blowing out of the breather on the way down but my husband thought he'd overfilled it. The engine ran sweetly all the way there and back. a) what have I done? Had I realised it was the oil pressure light I'd have stopped but as I say, the engine ran like a dream. b) is it likely to be terminal/expensive? I am hugely fond of this old lorry which has a brilliant history and I only bought it exactly a year ago. Any help very MUCH appreciated.

Olga, September 2008

Check the oil pump.
It could damge the crankshaft.

Vishal Sookoo, October 2008

Any engine has to breath, but if oil is blowing out of the breather it is a sure sign that there is excessive piston and piston ring wear which enables the combustion gasses to pass into the crankcase and build up preasure which forces out through the breather. This is not caused by blocked oilways.Most engines allow exessive crankcase gases to be feed back into the inlet manifold to be burnt. Maybe the breather pipe is blocked? Low oil preasure indication could be caused by a faulty oil preasure relief valve or it maybe just the oil preasure sensor switch which is the first thing to change. Also if the oil filter is blocked most of the oil is dumped back into the sump and may result in low preasure.If you have an oil preasure gauge fit this and see what the preasure is. A cold engine normally has good preasure as the oil is thicker. When it is hot the oil is thinner and the preasure may drop if you have worn bearings. I would assume that given the age of the vehicle it has done a few miles and would suggest that if the oil preasure switch is not faulty you are loosing preasure through worn crank shaft bearings.

Matt W, October 2008

First thing I would do is check your oil level and top up as necessary. If there is no or next to no oil left you could have done serious damage. Filling it up to the correct level and take it for a short run to see if it smokes or not, and see if the warning light goes out or not. If you are lucky it might just be the oil pressure switch which is faulty and all will be ok. If you are not lucky it could be a lot more serious. Usually when you run with little or no oil the temprature creeps up a little more than normal. You also say that it was blowing oil out the breather, this could mean that there is a blockage in some part of the oilways hence blow back. As it ran sweet all the way home I am hoping for a good ending. Good Luck

B, September 2008