Ocean30

Cheers Tony. I wondered if someone had the crank shaft out once and welded a shim to the original lobe that would have been cast. It’s really weird for sure. I’ll get hi to order an electric pump and blank off. Might stick a camera in the hole to see more. Will keep you posted.

Ok here we go! So a friends 1.8 BMC had a run away incident due to pump seal failure and subsequent diesel in the oil. A common story, however….we replaced with a re furb pump and got it up and running before it would just die again. So, checked for air and no air. Changed filters etc and came back to the lift pump which was also replaced. Now this is the interesting bit. It seems like the lift pump is not pushing through fuel. As if the lever is not being activated by the cam lobe on the cam shaft. It has been healed in correctly so I know this is not the issue: when I placed my finger on the lobe on the camshaft and felt about I could feel a piece of metal spinning freely on the cam lobe. We turned over the engine and found that there was little movement on the lobe. I then held the pump in place with my hand and got the engine turned over. No resistance or pressure pushing the pump towards my hand. my hypothesis is that during runaway the Cam lobe on the camshaft has somehow failed and has become in effective? Thoughts? My friend is now considering blanking off fuel pump and fitting a in line electric pump. anyone fine this and any recommendations? Thanks for your help as always. Simon

I feel I’ve gone full circle all the way back to the pump. I had a good discussion with a local diesel pump refurbisher who when overhauling the bmc pumps replaces the bushing in which the main drive shaft sits. He has such good knowledge of the pumps. We looked at the newly refurbished pump from Calcutt and agreed that the o ring had gone on the guide dog causing diesel to leak through the centre of the shaft. I thought I would have a look at what had happened out of curiosity to the refurbed pump, I had assumed that the o ring would have been replaced. Well I was wrong. Obviously got missed. Found a brittle perished o ring that I’ve now replaced. Probably missed on the overhaul. Chuffed that I found it. so I’m back to another pump being fitted and hoping that the case can now be closed. Now where have I said that before…..😳😂

It is a 1.8 Tony?

Thanks Tracy i think I’ll definitely need both the part that the pump mounts on to as well as the diesel timing cog. I’m guessing both parts will where out together? I’ll service behind there as well. Looks like I’ll be missing the enjoyment of boating for a while 😢

I know I keep going on but…… I stuck my finger in the master spline shaft hole and found considerable forward and aft movement where the tip of the diesel pump locates. Further more it looked like it wasn’t sitting central. As I rotated the engine it would become tighter before becoming slack again. My hunch is it’s so worn it’s been rattling the life out of the master spline shaft in the diesel pump causing the seals to go. Given that I’ve gone through a couple of pumps this can be the only part left that would be causing it having replaced the lift pump twice. I’m going to have the timing chain cover off for a proper inspection before I do anything else. Feeling a bit more confident that mil might be on the home straight.

It was a refurbished pump by Calcutt. I guess there’s no harm in sticking it in if I can get one? I’ve literally run out of reasons as to why this has happened. Keeps happening!

I was thinking that if the guide dog, part 45 was turning then the fuel could be leaking at this point any actually the seals?

So…….I know I’ve been on this for sometime but I think this could be the issue? when I removed the pump initially there was no torsion bar key. Thus I didn’t assume to refit one. Could this be the reason why I’m getting fuel in the sump? Exceed play in the shaft? Tony, thoughts.

Glad I’m diesel 😳

Now that is different! Such old engines though! I’m going to replace the timing chain and check for wear when she comes out for an overhaul at the end of the summer. I think the exhaust gasket is also blowing as she sounds a bit raspy and oil can be seen to be leaking. Tender loving care…..Or a new engine. Not quite sure yet. Keeps me occupied although so does working full time and raising a family 😂

No it doesn’t sound bad. I removed the lift pump a couple of days ago and replaced. Upon inspection of the old lift pump, which was new this year, I discovered one of the housing retaining screws had nearly totally undone itself. On the priming pump lever. I did do some serious priming when I refitted the new pump. Maybe worked it lose. I then checked the rest of the screws to find they were all quite slack. I wonder if this was allowing some diesel in? Chap from Calcutt boats suggested that if the tank is higher than the lift pump then the fuel can slowly drain in without you knowing much about it, even if the boat isn’t running. I’ve refilled with fresh oil tonight and taken her out for 30 minutes and oil level was unchanged. Gave her a bit of a work out. Oil pressure at 46 psi. So, I’m hoping and preying I fell foul of a poorly torqued fuel lift pump. Ive ensured the screws on the new pump are tight prior to fitting. I do hope I can finally close the chapter on this bloody saga! Please say a little prayer for me……😂🤦🏻🤯 Thanks for being patient. I hope what I’ve learnt can help others out.

I have a hypothesis. Could the Pump timing cog be worn causing excessive movement in the pump shaft when under load. Having seen the assembly stripped dow this seems a possible cause. Maybe I’m clutching at straws. Thoughts?

Me neither it is very strange. I shall endeavour to seek an answer.

I know Tony but I stuck I new one on so was ruling out it could’ve failed so soon? Replace it again? I suppose I could. Any experience of the lift pumps failing so soon? I certainly don’t want to be changing the pump for the 50th time😂. I was wondering if another interaction could cause the shaft seals to leak?