I've got coolant in my oil on my 3304 in a cat 930 loader, and upon draining the coolant I noticed a black color to the coolant. I was told it could be the pre combustion chambers causing this. If so, how would I go about diagnosing that? I'll be repacking water pump this week to hopefully address coolant getting in the oil.
It's extremely unlikely your water pump will be putting coolant in the oil. The precombustion chambers are notorious for developing corrosion holes if the coolant become seriously degraded and rust starts to form in the cooling sytem. Usually, a hole in a precombustion chamber fills the cylinder with coolant overnight, and your engine develops a hydraulic lock when you go to start it. Coolant leaks into the crankcase can also develop via leaking o-ring seals on the bottom of the cylinder liners. Take the oil pan off and fill the cooling system and get underneath, and you should be able to see where the coolant is coming from. If necessary, pump a little pressure into the top radiator tank. You can only find holed and leaking precombustion chambers by taking them out. Sometimes you have to chip corrosion flakes off the precom to find the hole.
Seconded. Does your engine have an oil cooler.? If so that could be a likely place for engine oil transfer to coolant and vice versa. Post a Serial Number so we can look up information.
Serial number: 41K6825 Engine: 78P32918 Thanks for the response. Engine does have oil cooler. I have yet to experience a hydraulic lock up of engine upon start up. It seems like the water only gets into oil while running. I'll pull pan and do an accurate diag. Also last night I noticed bubbles coming to top of radiator fill. Cold this be a head gasket that's causing all these issues?
I would agree with @OzDozer that would likely be the best plan of attack. You'll need a radiator pressurizing pump and get 10psi or so into the cooling system then see if coolant starts dripping. Maybe even pressurize it first without dropping the sump and just see how bad the leak is before making a decision to start tearing into things.? Who knows, something external may become obvious when you pressurize it.?
The black coolant could be carbon due to a head gasket or precombustion chamber leak. Is it oily black or just black?
Just black. Doesn't seem to be oily.
You can check the coolant and see if there is combustion gases in it. https://www.amazon.com/UView-560000-Combustion-Leak-Tester/dp/B000NPDL76
Bubbles in coolant can be from a head gasket or a holed precom chamber. I'd place the likelihood of a holed combustion chamber well above a leaking head gasket. The 3300 series engines rarely suffer head gasket problems, especially at the lower power levels such as in the 930.
I don't have any manuals for this machine, and I was wondering if there was a good resource for repair manual or mainly how to pull the pre-com chambers? Would it involve pulling the head or just injectors?
See the attached. You need to remove the glow plugs and the fuel injectors/lines. If you want to search for a complete service manual for your 930, look for Caterpillar Publication reference REG00514. A new one costs $795 in paper form, $565 on CD.
No need to pull the head, but you do need the precom removal tool, part number 5F8353 (it looks like a splined bolt), plus at least a 3' cheater bar, and a good quality drive bar, to get them out - because they're in TIGHT. You will need the big o-ring that seals the top of the precom chamber, and you will need the steel washer (called a "gasket" by Cat) that fits and seals on the bottom of the precom. The old steel washer will be corroded. These steel washers come in several thicknesses, and you select the thickness you need to ensure the precom ends up in its correct orientation for the glow plug alignment. There's a chart which has to be consulted which shows the required precom alignment for glow plugs when re-installing them. Use emery cloth to clean the o-ring seal area thoroughly to smooth, bare metal, lube the new o-ring with soap, put anti-seize on the precom threads, select the correct thickness of steel washer, and tighten the precom to 150 + or - 10 lbs/ft. D330, D333, 3304, 3306 – Precombustion Chamber Position | Caterpillar Engines Troubleshooting PRECOMBUSTION CHAMBER POSITIONING DIAGRAM 1. Center line of engine. 2. Center line of cylinder. A. “Go” range. B. Intermediate gasket range. C. Thickest gasket range.… www.catengine.info
Thank You @Nige and @OzDozer for the responses. I was able to get the removal tool for the chambers. would it be good practice to just replace the precom chamber while I have them out. I have the new O-ring seals and washers ordered. I wasn't able to find the service manual. Is there a particular site I can find them. Cat publications website was no luck. I'm sure its something I'm doing wrong.
I found this one. Believe it or not but Cat don't sell the Service Manual via their Publications web site. I have never been able to figure out why. Try HERE . This company produces Cat's Service Manuals.
At least you/we hope they are tight! If one or more come out easy be checking close for cracks in the head by where those washers are! I've seen some where when just trying to loosen the fuel line at the top the chamber turns, not a good thing! Replacing chambers would depend on how they look on the outside once removed. But if there is any pitting I would be thinking about replacing. I'll leave other thoughts for later!
New precom chambers are pretty cheap from what I recall - so for peace of mind, I'd be installing new ones.