KAD 42 Sudden oil dump into bilge

BruceK

BruceK

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Shakedown cruise this weekend noticed oil pressure drop from 50-60 to 30 at cruise revs and then started dropping to 25 After about 8 Nm on day 2. Shut down engine and noticed oil in bilge. Dip stick dry. Oil appears to have leaked out of oil cooler area. This winter I had the oil cooler out to check for corrosion and the source of a small weep. All fine and changed all o-rings etc. I think I might have displaced an o ring on reassembly....?

This is the second year I've tried to tackle a weep in this area. Obviously changing all o rings and seals etc blindly is failing. What I would like to try is to remove super charger and heat exchanger, run a water pipe from aft side of oil cooler direct to exhaust elbow and bridge the coolant lines from the now missing heat exchanger

Question.
Would running the engine without the intake manifolds from the bottom of the airbox and on top between the super charger and Y junction adversely affect the engine while running on the pontoon for a short period (before it overheats) so I can identify where exactly I am leaking oil from? Because right now it's just a mess with oil everywhere
 
In the same position as you,I would be happy to do that for a minute or so whilst looking for the oil leak. Make sure nothing can get sucked in - maybe fix some wire mesh over where the air is getting sucked in at the turbo (+ or- a bit of pipe) just in case.

can you just take the raw water impeller out, and avoid running water through the cooling system - might just simplify things a bit further?
 
I have used a USB endoscope connected to tablet / phone / laptop for leek detection into murky corners.
Think it was about £20 on ebay. It has proved very usefull for this sort of thing.
 
dpb said:
I have used a USB endoscope connected to tablet / phone / laptop for leek detection into murky corners.
Think it was about £20 on ebay. It has proved very usefull for this sort of thing.
Click to expand...

+1

even setup a broomstick, taped the endoscope, fixed it in place and then tested what I couldn't find. Sortof found it...
Endoscopes are V.Useful!

cheers

V.
 
Endoscope is a good idea. But I have to dismantle anyway to clean or I'll never find the leak. As it will be dismantled and then very clear to the naked eye I'd rather stick to the proposed plan unless someone can verify it's a bad idea and would be harmful for the engine. Thoughts?
 
FlowerPower said:
Seems like not the easiest approach.
I think I would remove the oil cooler and check again the seals on the mating face.
Click to expand...

This would make it the 4th time. 2 recently and one before when I swapped out the cooler. I want to see the trace leak before I get fixated on o rings which have been replaced. It might be the feed hoses or even a leak through the housing wall if there is internal corrosion and only blows under high pressure.
It may not even be the cooler. It's just in that vicinity
 
I wouldn't worry about running without the cooler at low revs for a couple of minutes.
I'd be more worried about getting parts of myself or some other foreign object getting sucked into the intake of a running diesel engine.
Feed hoses are for water, not oil?

.
 
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Just on the off chance, but have you checked the easy things like whether the oil drain plug in the sump is tight still?

I had a similar issue on my old boat , i was convinced it was some complicated oil leak from a cooler or pipework etc, didnt even think to check the easy stuff, turned out it was the sump drain plug, the previous idiot mechanic hadnt tightened it up correctly.
 
FlowerPower said:
I wouldn't worry about running without the cooler at low revs for a couple of minutes.
I'd be more worried about getting parts of myself or some other foreign object getting sucked into the intake of a running diesel engine.
Feed hoses are for water, not oil?

.
Click to expand...

Two oil and two water
 
julians said:
Just on the off chance, but have you checked the easy things like whether the oil drain plug in the sump is tight still?

I had a similar issue on my old boat , i was convinced it was some complicated oil leak from a cooler or pipework etc, didnt even think to check the easy stuff, turned out it was the sump drain plug, the previous idiot mechanic hadnt tightened it up correctly.
Click to expand...

I pray it's simple. But space with all the gubbins on really excludes an easy check. Only the aftermath. It's definitely not sump plug, it could easily be dip stick
 
Just a thought that I experienced on an AD130. The caps (item 8 on the diagram) are made of thin pressed steel, in this instance one had corroded slightly , enough to form a tiny pinhole that leaked oil under pressure. Didn't half make a mess after only a couple of minutes of running.
 
simonfraser said:
did you notice the pressure drop on the gauge only or did the alarm go off ?
Click to expand...

No I saw the pressure start to drop, monitored it in case it was a gauge issue and shut the engine down before it became critical or at least before the alarm went off.
 
tico said:
Just a thought that I experienced on an AD130. The caps (item 8 on the diagram) are made of thin pressed steel, in this instance one had corroded slightly , enough to form a tiny pinhole that leaked oil under pressure. Didn't half make a mess after only a couple of minutes of running.
Click to expand...

thanks for the tip. Judging from the magnitude of the mess something is spraying
 
For a guess you have displaced the seals where the coolers mates to the oil distribution housing .
Unless the cooler alloy housing and end caps are corroded I doubt it’s the cooler.
Don’t dismiss the 2 end covers that house the oil pressure valves , the end caps are mild steel and rot away , there is an o ring behind them .
I often use my I phone on video to look for leaks and then play it back, had to do this last week after I’d fitted an impeller , turned out the heat exchanger end cap wasn’t leaking . I nearly took the pump cover off as I’d fitted the impeller blind and refitted a new o ring as well as the cover , saved me an hour.
 
The KAD 42s often blow oil out of the dipstick tube if there is too much crankcase pressure and the oring is damaged or missing on the dipstick. Try simple things first as the dipstick is right above the oil cooler try wrapping some clean tissue paper around the top of the dipstick tube and monitor it.
 
Thànks for your response Paul. If I can clean it with everything in place so I can see where the oil is coming from with a camera or endoscope I will try that first. Strip it though in the end I must, I cannot reach it even with a spanner thanks to the engine room layout.
 
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