Diesel engine - gunky coolant flushing advice please.

[Yeoman_24]

I have a 28hp Beta Marine BD1005 which appears to have had a mix of antifreeze in.
It has what I can only describe as 'greasy gunk' inside the coolant filler cap. It isn't oil / water contamination as the engine runs sweetly.
What's the best way for me to flush the coolant 'crap' out of the system and what antifreeze is recommended for future use?
Thanks for any help. Simon

 

[Tranona]

Your manual will show you the drain point, or you can just remove the lower hose as the drain point will be small and probably bunged up. Refill with the coolant mixture recommended by Beta. This is a regular service procedure so good idea to learn how to do it.

 

[NormanB]

I have a 28hp Beta Marine BD1005 which appears to have had a mix of antifreeze in.
It has what I can only describe as 'greasy gunk' inside the coolant filler cap. It isn't oil / water contamination as the engine runs sweetly.
What's the best way for me to flush the coolant 'crap' out of the system and what antifreeze is recommended for future use?
Thanks for any help. Simon

A bit confusing this. If the ‘greasy gunk’ is in fact oil contamination that does not mean the engine will not run ‘ sweetly’ - that is not throwing a high temperature indicator or alarm. The danger of oil contamination is that the effects can be very localised and create the conditions of local overheating as heat transfer is inhibited. It may be that this localisation occurs in part of the cylinder head or in one of the passages around an engine cylinder or liner. In either or both of these examples engine damage can ensue.

You can clean out the cooling system using detergent which will need to be circulated by running the engine up to operating temperature. However, you really need to pin down if this is indeed oil contamination and if so identify the source. A first step is to put an ‘exhaust sniffer’ on the expansion tank to exclude that path.

 

[No Regrets]

Speak to Mike Knowles at TEC2000.

They make a range of products which work, from Engine flush, Cooling system flush to diesel additives. I have had extensive experience of these products working in real time (Fuel injected car slight misfire disappeared within 20 minutes, rattly Hydraulic tappets silenced within 30 minutes for example!)

My TAMD40b's wouldn't drain due to the taps being blocked, I ran them with TEC2000 'Rad flush' and subsequently flushed out gallons of brown sludge, which was strange because the coolant was always changed every two to three years!?

It's going to cost you around £10-20 for a good dose in a modest engine, I would recommend you try and flush the engine whilst running with a hosepipe in the top and a good bilge pump draining the old stuff for thirty minutes first though, you'll be amazed what can come out when you rev the engine whilst doing this!