Have just purchased a late model D8K. It runs fine but when it gets hot and you remove the oil filler lid it blows steam out there, but no water in the bottom of the engine or no bubbles in the radiator. Engine has only done 1500hrs on full out of chassis rebuild and block was done up then as well. Any ideas on what it could be?? Was thinking either cracked pre com seal or small crack in head. Interested to hear thoughts from other people as want to get the issue tidied up and put dozer back to work.
Do you loose water level in the radiator ? just a thought,but to make steam you need water, my guess is head gasket leak and coming back through the valve stem .
Maybe a very small amount. Hard to say haven't owned it for long and when I found this I have put it out of work so I can rectify the issue in case it does more damage. Just the fact that it only does it when the motor warms up makes me think it is a crack somewhere.
You could test the oil to confirm that it's getting glycol in the oil, and not burning off water.
How is the engine oil,Milky at all?
Oil is perfect. No water down the bottom at all. Just dropped it yesterday and caught the first few litres as that would be where the water would be and no milky oil at all.
never seen a d342 head without a crack in it!!! usually not into a water galley though. if no bubbles then leak is not in the combustion area i.e. head, head gasket, liner etc. be sure the weep hole in the water pump didn't get pipe plugged or solid freeze plug installed. is blow by tube gray looking oil? always check oil in the morning when engine is cool for overfilling this is when oil coolers fail. you may no see light bubbling in the radiator because the fill cap is dead center and return from engine is offset to one side. rain can get into new 5 gallon buckets since oil has been changed like 6 times since overhaul water could have came from there (been there). miss directed steam cleaner also gets oil in engines............theironoracle
Would have thought there would still be some water down there if there was glycol in the oil just from the condensation as the steam only comes out when you take the cap off.
i have seen head gaskets that showed no signs of failure, didn't know it was leaking until the valve cover came off and the inside was milky, the steam rises to that point then will actually condensate as i comes down the tube and you can never see those small drips...........tio
Have just taken the heads off and head gasket looks fine but maybe it was leaking. It was as you said milky inside the rocker cover. Am going to get the heads pressure tested and hope that something comes up to give me some piece of mind. I just don't want to not find the problem clearly and risk putting it back together to find it still does it. If it was only a small crack the bubbles may not have been that clear in the radiator.
take a long hard look at those head gaskets. look and the compression ring extremely close. does it make you 100% positive they were sealing? is there anywhere that they are dark from exhaust gas or are they perfectly shinny all the way around? the liners in these engines are a bit finicky, i have spent hours cleaning, rotating in there bores and moving them from one hole to another to get them the protrusion in spec under each head. if you have a decent camera take pics of each side and post them. i have a picture of a failed head gasket from a 3306 with about these hours posted in my thread "all in a days or two work pics" under shop talk, take a look...........tio
Is this the early Series K with the non Spacer Plate 342? if its the Spacer plate block does it have the water cooled Turbo and after cooler fitted? Steam from the oil filler most often comes from the top end, but as already pointed out the waterpump needs checking, after the engine has stood for a few days any water in the sump drains out in the first few pints out of the sump drain valve.
be sure the engine is running hot enough and long enough to drive off normal crankcase condensation. Be sure all crankcase vents are clear and working properly.
This was my thought, repeated starts without running long enough to evaporate condensation inside the block. It can accumulate
Im thinking i'd check the oil cooler out.
Sounds like blow by to me. Are you sure it is not just blow by ? This is usually the case and typically if its a head gasket issue you see a pressuring of the rad. It is quite possible that engine has been run warm and taken a little life out of rings. The 342 can run along time even with what seems alot of blow by. I beleive this is your problem otherwise you would have milky coloured oil to create any amount of steam vapour.The milky valve cover is usually sign of plugged crankcase breather.any amount of leakage usually makes oil milky.
I'd expect enough of a leak to cause steam from the crankcase would yield some free water/coolant. Does the exhaust show any indication of excess steam? It takes very little coolant in the combustion chamber to give steam and a noticeable odor... it smells like hot Coca Cola to me.
It is one of the last k's made. It has a water cooled turbo and after cooler fitted. What are the major points to check on water pump? Engine stood for a few days and there was no water in sump.
Pretty sure not blow by. What key things should be checked on oil,cooler
Where and how many crank case vents are there?
Only one filter on the oil filler tube and check the hose that goes down in belly pan for blockage.This is a common problem on these old tractors.Are you losing coolant or just seeing water vapor at oil hole? Good luck Bob
Pretty much just seeing water vapour at oil hole
I tend to agree with steve, water or any condensation will make your oil go gray then milky. you said you did a full overhall, did you use aftermarket heads? I had a new head with an exhaust valve completly chop out the guide in 250 hours. It had what looked to be alot of blowby but was exhaust gasses from the worn valve guide. Worth a check, bill
Not the oil cooler There is a few things to look at when assuming its the oil cooler. 1 the engine oil pressure runs near 60 psi and 2 the rad runs 15-18 max when hot. Most always when oil cooler lets go it dumps oil in rad. If crankcase vent plugs off the engine cannot get rid of the moisture that naturally occurs in every engine because its under pressure. I beleive the vent on the 342 is built into the side of block. Can't remember for sure otherwise it's in valve cover. If you have clean oil and no pressure in rad I doubt it's coolant leak. Another thing to remember is if breather is plugged when you open the filler all the blow by that normally wouldn't see is coming out filler hole and not the vent. Which can seem like alot.
Like TXGOAT says these engines need to be run long enough to warm up and to boil off condensation.The breather filter needs to be cleaned at every oil change.You might check the water regulators before you put them back in. Good luck Bob
If its blow by, you'll notice it. Eventually. We had an old 3406 that had been rode hard and put away wet. Near the end of its life, you could pull the oil filler, and it would have a nice pop, pop, pop, letting you know that each cylinder was still moving.
Good point ! I guess heads are off now but if you could've held hand over the filler and breather is plugged it will lightly try to blow your hand off. Maybe they didn't get a good ring seal after rebuild.also remember your engine is running at 180-210 degrees not near enough to make steam. If its leaking compression you'll see it as rad pressure.
D342 motors run the oil pump on Positive Displacement control that runs a good bit lower than 60psi, but I tend to think the engine would have best been put up against a few good shifts before a pull to bits, if water was not traced in the sump after the engine had been stood over night, I think its best to let things develope some after running a socket over the head bolts, the Valve Guides on the exhast valves do wear the most, but there is Roto-Coils below the springs that help this situation plus oil feed pipes that can be a fiddle to tighten without the "bent spanner" the Cylinder Heads are often mixed up with 1 head running 3/8" valves and the other fitted with 1/2" valve stems, I am currently rebuilding 2 of these engines (342's) they always suffer with piston pin wear and oil pump drive shaft dramas, I always use pucker CAT drive shafts on replacement.
Update. Heads were tested and found poor pre com seal possible cause of problem but was not convinced so went further. Pulled the water pump off and found that the tell tale hole was completely blocked and the water was sneering through the seal when it was hot. Problem solved and looking forward to putting it to work. Thanks for all your help.