Oil in engine coolant

[Slim]

Over the last few months I've done some major work on my stern gear and gearbox/engine. New stern tube,, shaft, gland, driveplate,  flywheel casing, engine mount bracketsy and flexible mounts. The list goes on and on. I did not do any work on the engine itself. After resolving issues around bleeding the fuel system I was finally able to get back onto my mooring earlier this week. Since the work the engine has run for about 3 - 4 hours faultlessly. Forgive the above details but trying to set the scene.

Earlier today I was down the engine hole and one of the checks I did was the coolant level.The exaust/ header tank was full of engine oil. Checked the sump and there was only 1/2 an inch or so of oil on the dipstick.! There was absolutely NO sign of water or emulsified oil in the sump or on the valve gear (through the filler cap). The oil in the header tank showed no sign of emulsification. I checked the oil in the gearbox as both box and engine have oilcoolers and that's fine. Sucked the rest of the oil out of the engine with a Pela as best as I could with cold oil/thin tube. Got about 1.5L  maybe a bit more out and again no emulsification. Nor was there any on the end of the Pela tube. As I see it two possibilities, head gasket or tube in oil cooler. I 've convinced myself it's not the head gasket as the head was last off about 800 hours ago. As part of the work mentioned above I removed both coolers and took them home to make new mounting brackets. No work on the coolers as such but they were handled quite a bit.

Views and opinions welcomed. Won't be able do anything for a week??  or so as I've got to go home tomorrow for some eye surgery. Also can anyone suggestchow I might clean out the cooling system. I guess a good squirt of Fairy Liguid might not be a good idea.

 

Many thanks

 

Frank

Edited January 11, 2020 by Slim

[ditchcrawler]

I had this and it was an oil cooler failure   

 

Edited January 11, 2020 by ditchcrawler

[Slim]

12 minutes ago, ditchcrawler said:

I had this and it was an oil cooler failure   

 

Thanks for info. I know that feeling of panic, I'm just getting over my attack!. Ran out of light so didn't attempt to take it off. Will do so tomorrow am. How did you clean the oil out of the cooling system?l

[Bee]

Have you got antifreeze in the engine? If it runs OK with no sign of steam once it has warmed up I doubt its a head gasket. For their to be enough oil in the water to really see it I would think of oil cooler, Sounds like its the engine oil cooler too. I think I would take it apart and see if there is oil where there didn't ought to be. 'O' rings OK?

[ditchcrawler]

This was mine, I couldnt see it until I pumped it up.

 

[Onewheeler]

2 hours ago, Slim said:

 Also can anyone suggestchow I might clean out the cooling system. I guess a good squirt of Fairy Liguid might not be a good idea.

 

Have you a bleed tap at the top of the skin tank? Oil floats so take out as much as you can there, top up the water, repeat, run engine to stir it up, etc. You'll get most of it out that way.

[BEngo]

You really need to clean the oil out of the engine because it seriously reduces heat transfer to the coolant, leading potentiallg to localised overheating.

First find and fix your leak- my money is on the engine oil cooler.

Ditch the current coolant and replace with ordinary water containing about 500g of washing soda in every 5 litres (From your local supermarket).  Run  up to temperature and circulate for 30 min.  Drain and repeat. Fill with plain water anx run up to temperature for 30 min.  Drain. Fill with diluted antifreeze of your choice.

Don't  use Fairy or the like it is full of salt and foaming agent and you don't want either in your cooling system.

 

 

N

[Slim]

58 minutes ago, BEngo said:

You really need to clean the oil out of the engine because it seriously reduces heat transfer to the coolant, leading potentiallg to localised overheating.

First find and fix your leak- my money is on the engine oil cooler.

Ditch the current coolant and replace with ordinary water containing about 500g of washing soda in every 5 litres (From your local supermarket).  Run  up to temperature and circulate for 30 min.  Drain and repeat. Fill with plain water anx run up to temperature for 30 min.  Drain. Fill with diluted antifreeze of your choice.

Don't  use Fairy or the like it is full of salt and foaming agent and you don't want either in your cooling system.

 

 

N

Thanks.

Actually the Fairy Liquid quip was a joke. Many, many tyears ago a friend went to the US for his  company  for 6 months. They rented an apartment for him that had a dish washer. Never having used one he used a good squirt of washing up liquid. Suds everywhere.

BEngo, thanks for the tips

Onewheeler, theres a bleed plug so I'll pull that  out.

The only good thing, assuming it's as simple as an oil cooler , is that I've yet to give the engine compartment a good clean out after spraying it with diesel whilst bleeding it.

[WotEver]

13 minutes ago, Slim said:

Many, many tyears ago a friend went to the US for his  company  for 6 months. They rented an apartment for him that had a dish washer. Never having used one he used a good squirt of washing up liquid. Suds everywhere.

When my mum had not long had her first automatic washing machine she ran out of automatic washing powder. “What can the difference be?” she asked herself, as she filled the dispenser with OMO. About 30 minutes later we found the kitchen nearly a foot deep in foam. It was really very impressive. 

[Boater Sam]

A bit of oil in the coolant does aid the water seal on the pump but a lot is a problem.

If you have antifreeze in the coolant it will breakdown the oil but not emulsify it to any great extent so I would guess heat exchanger too.

To make sure, are there any gas bubbles showing up in the header tank? Be sure it is not pressurising with exhaust gasses when cold.

 

You say head gasket 800 hours ago, has the head been retorqued as recommended? If its a BMC it should be retorqued every 400 hours or so. There is an oil feed through the head for the rocker shaft but its unusual for this to leak across to a waterway but possible. I don't know how you would establish that this is OK without lifting the head but it may be worth torquing it now.

 

For peace of mind, check the gearbox oil level too..............................Just in case! As you were missed that you had already, sorry.

Edited January 12, 2020 by Boater Sam

[Slim]

5 hours ago, Boater Sam said:

A bit of oil in the coolant does aid the water seal on the pump but a lot is a problem.

If you have antifreeze in the coolant it will breakdown the oil but not emulsify it to any great extent so I would guess heat exchanger too.

To make sure, are there any gas bubbles showing up in the header tank? Be sure it is not pressurising with exhaust gasses when cold.

 

You say head gasket 800 hours ago, has the head been retorqued as recommended? If its a BMC it should be retorqued every 400 hours or so. There is an oil feed through the head for the rocker shaft but its unusual for this to leak across to a waterway but possible. I don't know how you would establish that this is OK without lifting the head but it may be worth torquing it now.

 

For peace of mind, check the gearbox oil level too..............................Just in case! As you were missed that you had already, sorry.

 

At this stage I'm hoping it's the oil cooler. It's a Polar the same as Ditchcrawler's.I'm up early to take it off and bench test it at home. I'll check the head nuts before I refill with oil

Thanks

 

Frank

[Slim]

On ‎11‎/‎01‎/‎2020 at 20:07, ditchcrawler said:

This was mine, I couldnt see it until I pumped it up.

 

Thanks Ditchcrawler, you were on the button, stack to outer body which was covered up by the end cap. I used 2 Schrader valves in 15mm compression fitting nuts (the cooler nipples are 1/2" BSP which is about 20-21mm dia) The fracture was such that my 4-5 CFM compresser could not build up more than about 20PSI.

A new cooler is on the way from ASAP Supplies for £91. I did consider brazing it and have the kit but for £91 it's just not worth it.

As an aside, a few weeks ago Bowman told me their oil coolers were specced to 3000 PSI. Hope they're right 

[Slim]

On ‎11‎/‎01‎/‎2020 at 21:26, BEngo said:

You really need to clean the oil out of the engine because it seriously reduces heat transfer to the coolant, leading potentiallg to localised overheating.

First find and fix your leak- my money is on the engine oil cooler.

Ditch the current coolant and replace with ordinary water containing about 500g of washing soda in every 5 litres (From your local supermarket).  Run  up to temperature and circulate for 30 min.  Drain and repeat. Fill with plain water anx run up to temperature for 30 min.  Drain. Fill with diluted antifreeze of your choice.

Don't  use Fairy or the like it is full of salt and foaming agent and you don't want either in your cooling system.

 

 

N

Went to my local , large Tesco earlier today looking for washing soda. Couldn't find any so asked an assistant. She didn't know what I was talking about. I know a little hardware shop that is bound to carry it.

 

Frank

A lot happier than I was a few days ago.