Head gasket

[Tristan30]

How does one know, if the head gasket if gone? My Volvo KAD 43 -97 overheated in summer 2001. The engine was losing fluid from the closed circulation before this event (I suspect it maybe because of a leak in the warm water boiler -hose), but it is losing more of it now. Also after turning off the engine after say, an hour's drive, there is a fume of diesel in the engine room. There was also a funny smell, when the engine was idling, after the boat was taken to the water in the spring (maybe because there was anti-freezing fluid in the circulation after winter).

Otherwise things seem pretty normal. There are no leaks visible outside the engine block. There is no oil in the closed circulation. The air filter seem pretty clean. The engine is revving as normal and the all the horses seem to be in the stable.

Has anyone had similar problems? Spannerman?

 

[mtb]

You need to get two pressure tests done
one sort of cancels out the other !!, first is a compression test , which should show if a cylinder is down .
Then if it seems ok run the engine up to temp then do it again , it's not so much the compression figures more which cylinder is down ( it may only happen with the engine hot )
You may find no difference and it could seem fine !! another clue could be the colour of the injector nozzle you'll see if water has been in that cylinder .
Next using a radiator pressure testing kit pump the pressure up re the fresh water side of things , this will show two things one if the pressure can be obtained two if the pressure drops , look for the leaking hoses and pipes .
You may be able to see which cylinder is not running right by undoing the injector pipe ( don't let the diesel inject onto your skin !!!!!!!)
After doing this you may not be any closer to finding the fault it could be other faults like the seal on the water pump ( look for the tell tale water mark ) or a distorted / cracked head .
Again just listening, could tell you if the water is boiling and causing steam pressure which will send the temp over into the red and beyond.

Cheers
Mick

<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[spannerman]

If you have coolant on the engine room floor check the joint between the turbo and the exhaust manifold, I have changed many of these gaskets, Volvo had such a big problem that they have introduced a new type of gasket and even these have leaked on occasion. Run your fingers along the joint on the under side of the turbo, or try an inspect it visually if poss, also check that the drain plug at the bottom of the turbo is tight as this can leak also, check carefully as a leak from the gasket naturally runs down to the plug and it can appear that the plug is the culprit. If its leaking from the flange joint its not too difficult to change, it takes about 1 1/2 hrs, but you MUST drain the coolant down from the block or when you remove the turbo coolant will flood into the ex manifold and cylinders.Also check the flatness off the manifold face and file if need be as its aluminium and can be disorted by heat. If there is no external coolant leakage evident, then the next step is to pressure test the cooling system, if it doesn't hold up then you are looking at either a leak in your calorifier, taste the hot water side for glycol or coloured water, you can double check by connecting out and return on the engine together taking the water heater out of the equation. If you still lose pressure then its most likely you have cooked the head gasket. This is the 40 series weak point, they don't tolerate overheating for very long before it is game over, I wish I had a pound for every one I have changed!

I hope its something simple regards Steve

 

[Buck]

Have a look at the oil filler cap, if it looks like it has a milky deposit on it this would indicate water contamination in the oil probably as a result of head gasket failure.

Buck

Relax, life is just a game.

 

[tr7v8]

A quick chek thats always stood me in good stead. Top up the freshwater side of the coolant and leave the cap off. Start the engine and as it warms up if it's a head gasket you'll see a stream of small bubbles rising up and out of the header tank. When you give it some revs the stream will get stronger.
Never fails, last time I was sucessful was on Clive Neighbors Perkins!

Jim
-----

 

[DavidJ]

Spannerman is right in his report on Volvo head gaskets. Have a look at the forum on http://boatdiesel.com and you may be able to pinpoint if you are pre or post the various mods to head gaskets.
I wish Volvo would leave things alone sometimes and stop doing value analysis exercises on things that work and introducing unrealiability.
David

 

[spannerman]

David has hit the nail on the head regarding Volvo, they have made a very good series engines starting with the original TMD 40, then they tweaked it up into the TAMD41 again a very good engine. Then they stuck a supercharger on it and called it the KAD42 and guess what they all got recalled to have the headgaskets replaced as they leaked coolant down the outside of the block, I must have done over 40 headgaskets in the first couple of years after it was introduced. Then they were recalled to have piston splash oil jets replaced with ones of a smaller diameter ( higher pressure = oil squirts further) as they were suffering from cylinder scuffing, not suprising when you consider you are now pulling 240 hp out of a 3.6 block originally delivering 140hp. And now we have the KAD43 and 44, and wait for it KAD300! which despite its misleading title delivers 285hp all from a block designed 30 years ago, It will be interesting to see how they hold up. Don't get me wrong I like Volvos but as a marine mechanic I can honestly say in the last 6 yrs I have never done a head gasket or rebuild on a Mercruiser diesel, whereas Volvos keep me busy all year round. Just goes to prove there aint no substitute for cubic capacity, the new Mercruiser 300 D-Tronic 4.2 is a genuine 300hp and goes like a train, I just pulled two Volvo 41's out of a Nimbus 36 Coupe and put in two D300's and this boat fully loaded at over 9 tons does 42 knots on the GPS! Owner is over the moon, and they are very economical.

Steve

 

[Guest]

I agree with Spannerman with one possible addition (if it applies to your engine) Volvo heat exchanger matrixes can leak ie the fresh water coolant escapes into the raw water and hence out of the exhaust ,without trace. is this a possibility? If this is the case they can be repaired. First check to see if your water level is OK, then check to see if water is coming out of the pressure pipe overflow often not seen as pipe goes into bildge and water ejected by bildge pump.
Just a thought
Rob

robinwdunham