5400 hr D5G (3046T) needs a head gasket. Blowing bubbles out between the cylinder head and cylinder block deck. Loses 20L coolant/day easily. Not entirely certain where the coolant is going, but tech insists it will be collecting in the belly pan. Its not in the crankcase. Oil pressure is also low at idle. Rises when cold, or at rated speed. I am planning on having them drop the belly pans and pull the oil pump for inspection. They will pull a main and crank journal for inspection. Head to be inspected for warpage etc, all the usual inspection. Is there anything else these units are known for, to tell the tech to check while its apart? By the time its done i want an engine I can depend on for many years. Thanks everyone, Ken
Is it leaking on the Lh side of the engine? Have seen many heads leak at the small core plugs. Later Bob
I'll have a look. When viewed from above through the hood inspection hatch, you can see bubbles forming at the head gasket right behind the water pump housing.
Had problem like this once and ended up being a bad water pump. Check the bottom of the water pump and make sure it not leaking there. Had a shop teacher tell me one time that when it leaking from there it means a bearing went out in the water pump. (bottom of water pump)
If you find it to be a head gasket andare going to have bearings checked I would pull eng for rebuild and change the drive coupler before it fails on a site. It takes about 5 hrs to pull eng
I can't see how the coolant can accumulate in the belly pan. The belly pan, at least on my D5G, is a flat piece of metal. Any liquid like antifreeze would just run out and could not accumulate there.
From what you've said, the coolant will be going out the exhaust... If it were my money I would sample the oil rather than strip and inspection. Cheaper and arguably more accurate. Block test or compression test once hot. Will determine which pot the damage is from. Also the bubble can be tested to see if it is combustible gas.
I'd go with an oil analysis too, this is one case where you don't need to look for trends. There may be glycol and/or water present in the sample which would clinch it right there and then. If there isn't then either look at lead which indicates crank bearings - they're the first thing antifreeze in the engine oil will attack. However your low oil pressure might indicate the lead has already gone from the bearings so that might not be a guaranteed indication. If lead isn't conclusive then look at Sodium (Na) or Potassium (K). They are both present in coolant and IMHO more than 10ppm of each would indicate an internal coolant leak into the engine, even if the lead, water and glycol tests all came up negative.
Well maybe his belly pans are like some I see in our company. almost full to the top of frame! Too many people think the only time to drop them is when you absolutely have to to fix something. Not a a normal periodic maintenance item, almost have to wonder if those guys bother to change their undershorts on a regular basis?