White Smoke at >2500+rpm

[Rocketman]

Originally Posted by Pegleg Sands

you're absolutely correct.But if it's getting ib the combustion chamber,you've got a problem.And you'll be washing a cylinder with antifreeze,and the unburned coolant will be coming out the exhaust.I thought the moderator said they couldn't isolate a particular cylinder. I've had a faulty heat exchanger do this.The coolant was leaking into the raw water.A blown gasket isn't the end of world but I'd check everything I could before pulling the head.I've had Detroits that had an O-ring around each cylinder.I have a little experience with diesels and it can be a big job for someone with no experience,but definitely do-able.

While everything you say here is correct, it isn't a hard and fast rule that coolant will get past the piston into the oil. If it is a small leak into a cylinder then the coolant will turn to steam and exit the exhaust. If the leak is allowed to get worse then I would imagine that coolant could get into the oil as you state.
A compression test is the next coarse of action. With that information you should be able to tell which cylinder, if any, is low in compression, then with that information you can determine that the head gasket has a leak. Having the compression information is also a great indication of general health of the engine. If the compression is close to factory spec's you know that your engine is generally in good condition.

[Pegleg Sands]

Yeah,I've got an old Westerbeke 4-107 and I clogged the seawater strainer with a plastic 6-pack thing.Last year I pulled the engine and rebuilt it because it had 3200 hours on it.Honed it,new pistons,bearings,valves,etc.I went to synthetic oil and couldn't be happier.I put an oil change pump out kit on it.What a great invention. I've found in most cases oil will get into the coolant rather than the reverse because your engine will have 40-50 lbs of pressure.I've pulled a reservoir cap and it was bubbling and smoking every time that cylinder fired.Oil in the coolant usually was a crack in the block.

[delmarrey]

Originally Posted by Pegleg Sands

I've pulled a reservoir cap and it was bubbling and smoking every time that cylinder fired.

You must have had some really fast bubbles.

[Pegleg Sands]

If you've never seen it I guess it's hard to picture.I've fixed three or four warped heads or blown gaskets over the years.That's the most common symptom along with white smoke or coolant in the oil.I had a 3 cyl Kubota gen. that had a warped head.I just left the radiator cap loose so the compression didn't build up.I used it for 4 years that way.Talk to any experienced diesel mechanic before you decide it's BS