head gasket?

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bjames1955

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I have a perkins 6354 6 cylinder engine which I purchased earlier in the summer and fitted to my Harbour service launch. It ran up ok though a little smokey until running under load. It got us across the channel and up the seinne without missing a beat and we are now wintering at Sens.
The (fresh water) cooling water has been topped up on several occassions and the oil level is now about 2 inches above the high mark and clearly mixed with water. The other worrying part is that on two occassions whilst trying to start it a small amount of water (raw?) has been ejected from the air intake. I am about to strip the engine down to replace the head gasket but before I do any ideas as to the problem?
 
If that really is raw water being ejected from the air intake that is difficult to explain unless it is comming into the cylinders from a flooded exhaust. If it is not raw water then it could just be condensation of water diven off from the now very wet lub oil via the crankcase breather into the air intake, if that is how your engine is vented. If it is raw water then it needs investigation, are you turning the engine for too long before it starts with the inlet seacock open. That would probably cause waterlocking though.

If the fresh water pump is directly driven, rather than belt driven, do not overlook the posibility that water is getting past its seals into the sump. It's a lot less work to replace pump seals than head gaskets.

If the engine really is running sweetly and starts easily the head gasket would not be the first thing I suspected
 
Another possibility is that raw water is getting into the system via the engine oil cooler.
The freshwater always has to be topped up from time to time so this may or may not be a factor.

Another thing to check anyway.

Usually if a headgasket is gone there is some effect on the running of the engine...ie water getting into bores...unless it is blown just between a water and oilway...which from memory on my 6354's were quite far apart.



Steve
 
I had a car like that, once. Water level went down and oil level went up! Engine seemed to go OK, but tended to overheat. When I took the head off, there was a break in the gasket from cylinder, through waterway to oilway. It had obviously been like it for a while ast the hot gasses had scored a groove in the (aluminium) head. On replacing the gasket and getting the groove welded over and ground flat all was fine.

All sounds very similar!
 
[ QUOTE ]
The freshwater always has to be topped up from time to time

[/ QUOTE ] If so then it is going somewhere. If it is not leaking externally or being lost via the filler then it needs to be investigated but the rising sump level and wet oil is a pretty good clue as where it is going. It's just a question of by what route.
 
The engine has not overheated at any time and I did wonder about the oil heat exchanger, I will look at these other factors before I start removing the head! I just wanted to get some ideas of alternatives to head gasket any more? Im not sure if the water coming out of the airvent was raw water or fresh?
 
The genuine perkins head gasket for the 6354 is rubbish, the laminated copper one always leaks around the back of the head.

you need to source a head gasket made by 'Payen', its a black jobbie, think they might be asbestos of some sort.

I fitted a pair 3 years ago and not topped uo the coolant since.

I think you troubles might be with a cooler tube split though.

Bit of a dab hand with the 6354 so shout if you need to know more.

HTH
 
many thanks I may well get back to you! I was told that the closed cooling system should be coolant not water (?) If I change the oil, top up the tank with coolant and turn engine over (or not?) and see if it leaks into oil maybe that will give me a better idea of where the leak is?
 
If you have water ejecting out of air intake, then forget oil cooler. You have a head gasket failure, exhaust manifold failure (or less likely a cracked head)
 
if it does turn out to be a cracked head, there has been a new one regularly advertised in the For Sale section over the last year or so.
 
One way to check cyl hd gasket is to run your engine for a wee while, remove header tank cap checkfor preasure build up, also stick your nose as close to it as you can and smell for combustion fumes.
When I worked in a garage we used to check for co2 in expansion tank by sticking the exaust co2 probe into tank, which was a good indication of cyl hd gskt failure.
 
As a rule a head gasket that is leaking compression into a coolant gallery will create loss of circulation and over heating. (bit like the home central heating system when it has an air lock!)

If the Gasket is breached between a coolant gallery and oil way then emulsified oil will show on the dipstick.

A friend of mine in Turkey owned a Gulet with the same engine, which had similar symptons to what you are describing! Turned out it was a worn oil seal drawing in water!

Found a forum for you that could help you further: Click Here!

Hope things get sorted. /forums/images/graemlins/wink.gif
 
[ QUOTE ]
could it be a cracked liner?

[/ QUOTE ] another posibility I suppose or a seal gone at the bottom of the liner between it and the block, depends on the design of the engine.
I belive in some of the old raw water cooled Volvo Penta MD series the liner can corrode through due to the proximity of the brass drain cock. That is low down of course so water gets into the sump directly without the running being affected.

Probably other possible causes as well but it struck me that going straight for the head gasket was ignoring one or two other more easily checked and rectified possiblities especially as the engine was running sweetly.
 
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