Perkins 4.108 Oil Exhaust maybe hot?

[JensK]

Hey guys,

ive got an Perkins 4.108 in a Boat. I have this boat not very long so Ill try to fix all the small problems.
Cooling system should be okay, I measure with an infrared thermometer round about 80degrees on Cooling Water and Temperatur sensor.

Yesterday is see that if the Engine is running, there comes black oil from the top of my Exhaust. Can you tell me what this is? It looks also like that this will be hot too?

Here is a Picture.

Thanks

[tkeithlu]

Welcome to the forum, JensK. Sorry I can't help you with the Perkins, but I am sure there are others who can.

[oldcal46skipper]

It looks like you may have a crack in the injection elbow fitting. This would allow hot exhaust gas to escape and cause the discoloration. I would remove the fitting, inspect it for cracks and repair or replace.

[JensK]

Originally Posted by oldcal46skipper

It looks like you may have a crack in the injection elbow fitting. This would allow hot exhaust gas to escape and cause the discoloration. I would remove the fitting, inspect it for cracks and repair or replace.

Okay i will check, but this is not only a "discoloration" there is definitely Oil, wich drips out?

[rbk]

Originally Posted by oldcal46skipper

It looks like you may have a crack in the injection elbow fitting. This would allow hot exhaust gas to escape and cause the discoloration. I would remove the fitting, inspect it for cracks and repair or replace.

X2 most likely just a mix of exhaust gasses which does resemble oil. Might even be a little oil mixed in with it for various reasons. Check for cracks and tighten the bolts as mentioned above.

[JensK]

hey guys I've done short video to show you my engine and where the oil is.

https://www.youtube.com/watch?v=Rxf3AwqDnA4

I will check the exhaust in the next day.

[JensK]

Here is a video from my Engine and the Problem.

https://youtu.be/Rxf3AwqDnA4

In next days i will take a look at the Exhaust Manifold.

[skipperpete]

Originally Posted by rbk

X2 most likely just a mix of exhaust gasses which does resemble oil. Might even be a little oil mixed in with it for various reasons. Check for cracks and tighten the bolts as mentioned above.

If you can't find any external source for that oil leak you might have to take off the exhaust manifold and see if it's an isolated problem on just one cylinder or shared by all 4 cylinders. Does your engine have a lot of blow-by? Do you idle the engine or run it light for extended periods of time to charge batteries etc? If so I t could be cylinder bore glazing.
How much oil are you actually using?
Finally, consider the intake and exhaust valve stem seals as potential culprits, when was her last top overhaul?

[TrentePieds]

I would add to what skipperpete has asked: Is you engine slow to catch on when you crank it? Will it sometimes seem to catch and run, but then slow down an die within a few seconds, so you have to crank it all over again?

If you wipe the leaking joint clean - like really clean - just before you crank the engine, how long does it take for oil to appear in the quantity your video shows?

TrentePieds

[JensK]

Hey thanks for you're Answers.

First we bought the boat in August, the before owner said it was 1year on land.
He made a new moisture separator, but I didn't know if he overhaul the seals and filters and something like that. I want to do that in new Season.

To you're Questions.

-- Blow out:, there is a normal Blow out, I think, the Blow Out goes into the Water, if I drive in high rpm I see blow out, outside the boat.

-- How often and how long the Ending runs:

How I said it was 1 year on land, since we got the boat we driven a lot and long time at least 1 hour. Not often I turned the engine for a short time on.

-- Oil. I don't use much oil, since we got the Boat It was not necessary to refill oil. The Oil is now a short bit under MAX

-- How long does the Oil take to appear in the quantity my video shows?
- I can't say because I cleaned it yesterday, but after cleaning, I turned the engine 20minute on, only on jetty and there was no oil..

Can I take the exhaust manifold off without problems? I have here in Germany not reals a seller for seals..

[TrentePieds]

Hello Jens:

Erstens, here is a reference to the workshop manual for your engine:

https://www.manualslib.com/manual/96...ins-4-108.html

Zweitens: When you say "blow out", do you mean "Auspuff"? I think you may have a minor problem with your Auspuff. You say the "blow out" goes into the water. Do you mean that die Abgase goes into the water because der Auspuff is led below the water line of the boat?

You say: " I turned the engine 20minute on, only on jetty and there was no oil.."

Do you mean that the boat is NOT in the water (i.e. that it is "on the hard" as we say in English)? If so, you need to be careful that you supply "raw water" as a replacement for the sea water the engine would normally be taking in when the boat is in the water. However, you MUST NOT supply it by means of water from a pressure hose connected to the water intake. Take a hose from the "in" side of the raw water pump to a biggish bucket you keep filled with water as required, and let the pump suction take the water to the cooling system in the normal fashion.

Here is the procedure I use for every startup from cold:

1) Wipe everything ABSOLUTELY clean so you have a known condition for reference.

2) Check both lubricating oil and coolant, and replenish to the reference marks. Wipe up anything you spill during replenishment.

3) Verify/correct belt tension.

4) Empty and clean filter on raw water intake if visual inspection of the glass bowl shows that it is necessary.

5) Start engine and keep 'er under observation until operating temperature is reached. Running at idle - about 950 RPM - verify by sight that cooling water is being ejected from the exhaust pipe (der Auspuff). You may or may not see exhaust gas (Abgase) at this time. Just at this point it's the water that is important.

6) If water does NOT appear, shut down the engine. This is important! If water DOES appear it should come in spurts rather than as a steady stream. If it comes as a steady stream, shut down the engine. If it comes in spurts, look for exhaust gas and note its colour. It may be gray, black or blue.

7) If the Exhaust is black, the engine is running rich, and the fuel injection will need adjustment. At idle speed, with no load, and at operating temperature, the exhaust should be clear (i.e. invisible)

8) If the exhaust is blue the engine is burning its lubricating oil, which is potentially very serious. We can talk about that if necessary. If you can start the engine, you can run it for a while without doing serious harm, but you'll have to begin to think about spending money on it.

9) If the exhaust is grey, there is water vapour (steam) in the exhaust. This is either trivial or serious. Nothing in between. Shut down the engine and determine how the water is getting into the exhaust. Most often it is the raw water being injected into the exhaust (Auspuff) in order to cool it. But sometimes it can come from a point before the injection point for the raw water, and if so it is potentially serious. So if you are seeing steam in the Abgase, shut down and verify that you are not loosing cooling water (coolant - the stuff with antifreeze in it).

My first impression of where the oil in you picture is coming from is that is the gasket in the joint that is leaking. You can easily take the joint apart and make a new gasket yourself. That may cure the leak, but you still have to determine where the oil is coming from. There should not be liquid oil at that point.

So have another go at it and get back to us with what you find so we can help you better. By our rules the language of the forum is English, but if you find it easier to explain things in German, you are welcome to do so in a private message to me. I can probably still remember enough to translate it and put it on the forum for others to respond to :-)

TrentePieds

[rbk]

There will always be some burnt oil mixed into tour exhaust gassed with a 4108 as the crank vents directly into the intake. Like Trent said wipe it down replace the 5$ gasket https://www.parts4engines.com/perkin...outlet-gasket/ and torque it down to spec. After a top end rebuild I had similar small leak after having to reseat the exhaust riser after a few hours of running (just a small amount after an hour, yours may have been leaking for years?) It is greasy like oil but it is just a mixture is exhaust gasses that you don’t normally get to see as they are mixed with water. If it is excessive (remove oil cap with engine running and see if there is significant air coming out) then you may have an issue. I will take argument with Trent that grey exhaust is water, it is almost always unburnt fuel from a cold or off timed/tuned engine.

[skipperpete]

Hi JensK
The term "blow-by" refers to crankcase pressure and is normally caused by compression leaking past worn Pistons and rings, also it can be caused by a blown head gasket if it leaks between the cylinder and the pushrod gallery.
You can observe the degree of " blow-by" by removing the oil filler cap while the engine is running, a severe case will exhibit a constant stream of combustion gas possibly carrying droplets of oil. A mild case is a gentler puffing of slightly smoky gas. Diesel mechanics refer to engines with this problem as "heavy breathers"
I definitely agree with replacing the leaking gasket but you do need to locate the source of that oil originally.

[Cheechako]

So that black wipes off? or is burned on? If it wipes off that's pretty strange, there shouldn't be much free oil in that exhaust vicinity and it makes me wonder how it gets there.
Possibly a bolt holding the manifold to the engine is adjacent to a oil passage inside? leaking out into the exhaust right there? I would think that would be hot enough to make the oil smoke...
Have you checked your engine water? does it have oil in it?

[JensK]

Hey guys,

First i want to say thank you very very mich for youre respons and youre help!

My Friend was yesterday at our boat, i am at the moment in Holidays, he cleaned al the black stuff away. After that he send me the following picture, and yes oldcal46skipper and rbk were right.

There is a Crack in the Elbow! And the black stuff is a mixture from exhaust and stuff, my friend said it is definitly no oil.

So we need to get a new elbow, or can we weld it?
Because the elbow is i think not the standart one fron pasrts4engine and a new one is definetly expensive.....


Thaaank you for youre help and youre massive response