Engine noises

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Graham_Wright

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Gloucestershire
www.mastaclimba.com
I have a BMC 1.5 diesel which (now) starts at the first touch and revs nicely.

However, despite its reputation, I am concerned by the noises it emits. I am deaf and high frequencies are lost to me.
Oil pressure is good and acceptable even when hot which hopefully rules out bearing slackness but having heard upsetting talk over crankshaft cracks and the like, I would like an expert opinion (and not be ripped off).
Is it worth trying to find an engineer (not necessarily marine for this engine) and asking for an audio diagnosis?

The boat is in Cardiff.
 
jrudge said:
It maybe worth cutting open the oil filter as if there is a metallic failure it should show up in the oil.
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Thanks.
What sort of metallic failure might that be? I have committed the (apparently) cardinal sin of adding an extra pulley to the end of the crank. It has been suggested that that can induce crank cracks.
Would it be safe to assume the sump drain plug is magnetic (although probably impossible to access in situ!).
 
No idea re the sump plug, but if it is a mechanical failure then the bits must end up somewhere and that somewhere is usually the oil filter. Aircraft engines have the filters cut open as a matter of course at each check / annual as it is a decent early warning system.

You could do oil analysis but that is of limited values as a one off - the trend being more important.

If there are bits an analysis can tell you what metal which can help isolate what is broken.
 
Graham_Wright said:
#1 -I'm deaf!
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I did read that you said that some areas of the hearing range may be lost to you, but perhaps assumed that you weren’t without hearing altogether. Apologies if this is the case. If it isn’t completely lost to you, you’d be amazed what you will pick up using such a method otherwise.
But to be honest, I think we are all guilty about over worrying about our boats and their engines. Although I am not overly familiar with your particular engine, I have spent half of my professional career and all of my living years around and about marine engines and plants. In my experience, there isn’t too much that can’t be told about the health of an engine by simply constantly being aware of and monitoring your pressures, temperatures, oils and fluids. Generally these vitals will tell you all you want to know about an engine. All are visually indicated too.
Id also perhaps maybe even suggest that given your unfortunate lack of hearing, you may also find that you may just have heightened levels of another very telling means of picking things up. That being feel. By this I mean you may be almost instantly be able to detect the slightest change in the harmonics or change of them through vibration or similar.
It’s also very cheap and accessible for the average joe to send off an oil sample for analysis these days. If you do this regularly, you can establish and monitor trends from the first sample onwards. Detecting any abnormal or raising levels of bearing material in the oil. Along with other indications too. Just a thought.
 
Seriously...............................
Ok so you spend money and time on a 1960s diesel engine oil check and it reveals its a bit worn and bit noisy....... Quelle suprise !
Big ends/ main bearing wearing a bit ,are you going to pull it and rebuild ?
Changed the oil recently, forget the oil check .
A more appropiate way , check the exhaust smoke, check oil is being consumption and whip off the oil filler cap to find out how much crankcase pressure there is.
This is not a MAN V10 with gold plated rocker covers.
One of the local fishermen or workboat owners has probably got one of these with twice the hours , burning more oil than fuel , ask him to have a listen ? :)
 
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QBhoy said:
Get yourself a stethoscope or listening device (screwdriver to the ear)…might put your mind at rest
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+1 - place the end on of the screwdriver as a stethoscope (I found a new acronym for the awful SaaS) on your forehead or other sensitive area. It is worth a try because it costs nothing and you might find you can detect abnormal vibrations or a very smooth running. Worth a try.
 
oldgit said:
Seriously...............................
Ok so you spend money and time on a 1960s diesel engine oil check and it reveals its a bit worn and bit noisy....... Quelle suprise !
Big ends/ main bearing wearing a bit ,are you going to pull it and rebuild ?
Changed the oil recently, forget the oil check .
A more appropiate way , check the exhaust smoke, check oil is being consumption and whip off the oil filler cap to find out how much crankcase pressure there is.
This is not a MAN V10 with gold plated rocker covers.
One of the local fishermen or workboat owners has probably got one of these with twice the hours , burning more oil than fuel , ask him to have a listen ? :)
Click to expand...
Harshly put…but straight to the point and I tend to agree, all things considered.
No harm in a man looking after or being concerned with the health of his engine…but yeah. You’re ultimately correct. No frills or sugar coating for sure though ?
 
oldgit said:
Seriously...............................
Ok so you spend money and time on a 1960s diesel engine oil check and it reveals its a bit worn and bit noisy....... Quelle suprise !
Big ends/ main bearing wearing a bit ,are you going to pull it and rebuild ?
Changed the oil recently, forget the oil check .
A more appropiate way , check the exhaust smoke, check oil is being consumption and whip off the oil filler cap to find out how much crankcase pressure there is.
This is not a MAN V10 with gold plated rocker covers.
One of the local fishermen or workboat owners has probably got one of these with twice the hours , burning more oil than fuel , ask him to have a listen ? :)
Click to expand...
The oil pressure is good and there is no smoke (except on starting cold).
I need someone with experience to listen to the clank and tell me it is normal (or not:confused:).
I have also checked the tappets' clearance. They were all correct or very near (0.015").
 
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