Julian Messent26 February 2015 at 14:15 #51174
I thought I would start a new topic for a bit of light entertainment and enjoyment for all.
Stories or funny / interesting findings while working in the workshop. I thought I would try to do one per month but it just depends on workload.
M45 oil pressure.
We just had an M45 Team car in for an engine rebuild after knocking noises were heard and no oil pressure.
Turned out that the oil pump drive shaft had seized in the pump body and snapped the drive dog. No oil pressure lead to a spun big end bearing. (this one was on shells)
The oil pump on an 4.5 as many of you know is driven from the cam and also drives the rev counter so a quick check to see if the pump is going round is to see if the revo drive is still turning.
The owner of this particular car is a very experienced competitor and driver and watches his oil pressure often, luckily he saw the oil pressure disappear and started checking other things etc,
In this case the pump/revo drive was still turning, the rev counter was also still turning so it was presumed that the pump was also working.
Luckily due to a wise head and some funny noises, the owner decided not to risk things and stopped the rally for the service crew to check inside the sump. All looked well and nothing could be found. (no oil pressure found either though)
Unfortunately the oil pump drive gear had sheared on the lower end which is very unusual, so the revo worked but the pump not.
Just goes to show that initial checks don’t always show what we expect.
Engine going back together now after a general rebuild and submurged arc welding up the damaged bearing journal, re-grinding and re-nitriding the crank etc.
(too much damage to simply grind unfortunately but little other damage)
Funny things these old cars.
Hope you find this a good idea.
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