I have an old D5, 96J0799 and have been replacing parts on it for many years. She’s an old sweet heart. Lately, she has been blowing a little compression into the water jackets and I could see a little wisp of steam coming out of the radiator cap. Since every component of the cooling system is new, I was suspecting (hoping for) something like a leaking head gasket). Today, I noticed that it was only firing on 5 cylinders. I brought it back to the shop and when I restarted it to do additional testing, it started pumping large quantities of water out of the exhaust. Am I looking at a cracked head/block. Advise please. Thanks.
Does it have precombustion chambers?
I don't know anything about the Cat 3306. It's about a 1969 vintage and is not turbocharged.
I'm fairly sure it has precombustion chambers. They would crack and let combustion into the cooling system. Its been a lot of years since I worked on them. Someone more knowledgeable will chime in here soon.
Circled in the illustration below. Whether it has precombustion chambers will depend a lot on whether the engine is original or a later model fitted at some point down the line.
Thanks so much. I will check this out as soon as I get back to the shop. Thanks again.
I doubt you’ve cracked a head or a block as you sound like you like the old tractor and haven’t abused it. Probably a much simpler explanation like combustion chambers corroded or water pump.
Thanks much. It's a new water pump. I ordered all new combustion chambers, fuel tips and glow plugs. I will dismantle everything next week and see what's what. You gentlemen are life savers. I didn't even know about precombustion chambers until mekanik and NIGE enlightened me. Your help is greatly appreciated. And NIGE! That's the second time you've come to the rescue for me. I will post results in a week or so. Thanks again.
In my experience failed pre chamber is usually a pin hole which causes a complete miss on that cylinder and pressurization you describe. Fairly cheap easy fix.
Thanks Tom. I noticed that before the failure it was missing on one cylinder. You answered that issue. Thanks again.
Be careful running it. I had a leaking pre combustion chamber and it washed the oil off the cylinder and the piston froze and it pulled the top off the piston.
Thanks. The second I saw water coming out of the exhaust manifold, I shut it down. I'm going to tow it into the shop. Thanks for the advice.
Ok! You guys are heroes! Thanks to you, my old 1969 D5 is once again, purring like the kitten she is. Much thanks to ‘Mekanik’ for pointing me in the right direction, and ‘Nige’, always the consummate pro (including a graphic). Thanks to Nicky 68a for the pointer. TomA for the clarification. And Don k, I took your comment to heart and pre-lubed the cylinder walls while I had the chambers out. All of the chambers were science projects with barely any material remaining in the water jacket area. Replaced them all including glow plugs and fuel nozzles. She’s tight as a drum and running like new. You guys are heroes. Can’t thank you enough!