Last Friday I traded my 53B in on a 53C 2ZN. While the shop was servicing the new machine, they found what appears to be engine oil floating on top of the antifreeze. Today, I received a call from shop. They've ruled out the engine oil cooler, i'm assuming they sent it off to be pressure tested like they originally said they would. The next logical thing to do would be check for a cracked head or block. I find it hard to believe that it's a head, because while I was operating it there was no sign of any pressure in the radiator causing the antifreeze to puke out. I didn't notice any sign the machine was burning the anti-freeze. The coolant level was in the normal range. Any suggestions? They're still diagnosing the issue.
More likely to be fuel instead of oil meaning that it is possibly leaking at one or more injector sleeves. Needs specialized tooling and knowledge to fix if that is the issue.
Yair . . . A question for Cmark, Nige or any tech savvy folks . . . I note Cmark's comment about specialised knowledge and tooling to remove injectors. What is the reason manufacturers need to have such exotic methods to seal what in fact is a smallish hole into the combustion chamber? I have always been puzzled at, for instance, the early Cummins system when similar engines of the era got by with annealed copper washers or, on some of the English stuff, soft steel. Cat were always "different" of course but I would not have thought the engine in the machine in question was all that special as regards boost and cylinder pressures and injector cooling requirements. This is probably an inane question but I have to keep the old mind churning.(big grin) Cheers.
It's all to do with cooling. The idea is to make the wall between the injector and the water jacket as thin as possible. I'm not a fuel system designer, but it seems reasonable to think that unit injectors, which seem to be the ones to use this kind of system, either make more heat or need to run cooler than conventional injectors. Presumably they had difficulty casting the feature into the head when they were developing the system.
Also, unit injectors are usually larger than simple pop-off injectors. I think that goes along with what Cmark says.
Yair . . . Unit injectors, that makes sense . . . don't seem to remember much of a to do to swap the injectors out on the GMs though . . . I found a couple of different 71 series timing tools in an old toolbox when I was cleaning out the shed. Cheers.
Cmark, I asked the shop about the injector cups being bad, and like you they feel if that was the case there would be fuel in the oil. That's not the case here. No antifreeze in oil, no fuel in oil just oil in radiator. Normally if there is a cracked head your gonna have combustion pressure going to radiator and causing it to puke the antifreeze out. Don't know, hopefully they'll get it figured out. Gonna stop by in the morning to see how things are going.
OK, fair enough. When they removed the oil cooler, did they check the condition of the gaskets and O rings in that assembly? There are places where these can fail and let oil into the coolant. Also when the cooler is refitted, the bolts must be correctly torqued and in the correct sequence.
Scrub, to just remove and replace the injectors doesn't actually require special tooling, it's when you come to synchronize and time them that you need the tools. The procedure is actually fairly easy. Removing and replacing the sleeves is a different matter however. You need both the tools and experience. It can be a tricky procedure and it's possible to bugger up the head if you don't know what you're doing. Before anyone attempts it for the first time, I'd suggest having a practice on a scrap head.
Fuel in the oil is possible but it would have to be getting in there by leaking into the cylinder bores past the injector seat when the engine is stopped, but this would also mean rough running due to combustion gases getting into the fuel rail when the engine was running. It's also possible to get fuel into the oil past the injector upper O ring which is nothing really to do with the sleeves. Leaking sleeves gives you fuel in the coolant or coolant in the fuel. It is possible to get coolant leaking into the cylinder and from there into the oil, but that would mean the coolant system pressurizing when the engine is running.
Yair . . . Gotcha Cmark . "Tools and experience" is the key. I have heard of a few calamities with the Cummins clone in some of the early 65 Komatsus. It was a good engine in my experience but needed specialised knowledge when it came to the injectors and sleeves . . . not too many folks familiar with the jigger up here on the Central Coast. Cheers.
Update..... Today they put in new oil cooler and gaskets. The tech said the cooler O-rings looked good and didn't appear to be leaking. The oil samples came back with no cross contamination, so no coolant or fuel in oil. They were in the process of flushing the radiator out with cleaner and was going to run it for a while to see what happens. Does not appear to be getting combustion pressure in the radiator. Kinda has them stumped, they've got emails out to other Cat techs to see if anyone has ran into this before. What's sad is, the engine runs like a top, no missing or stumbling, nothing....has a ton of power. The download they initially did, didn't show any codes for overheating, or running hot. They are going to run a leak down test next according to the tech. Stay tuned!!!
Did the previous owner replace the oil cooler and not get the cooling system flushed out well? That oil may have been in there for months.
d9gdon, I asked that very question, but right now we don't know. They were planning on flushing it several times to make sure and get it all out of there. I guess after they pressure test it we'll know a little more. I guess worst case scenario they'll put a new head on it, but hate to have it down that long. They're going to get me a loner figured out, so that's not bad.
I have seen many an antifreeze drain pan with a film of motor oil on top, and the mechanic just pumps the antifreeze back in with the film of oil...could you be chasing a ghost problem? Could a drain/flush/refill solve your problem? Howard
That's a good point! That is why I always kept separate drain pans made out of white plastic buckets and barrels to catch coolant. These were kept across the shop from where the oil catch pans were stored. Not knowing the full story/history of a machine can cause lots of unneeded work.
Question: What was the oil like, black, mayonaise, or what..? and do you have an idea how much of it there was in the radiator..? Hetkind's idea isn't so far fetched if someone has not been too careful about what they drained coolant into way back when. This also might be a good time (once you locate and fix the source of the oil leak) to put some decent ELC Coolant into the system.
Nige, The oil was "coal" black and about an inch and a half thick floating on top of the coolant. The oil was "caked" on the bottom of radiator cap as well. So I'm confident its not residue. One of the first things I asked was if they thought it was from a previous cooler change. They said it was hard to say, but it looked like the original cooler.
Well that would seem to eliminate it being fuel leak. Sure sounds like a bad cooler to me. Not being familiar with the engine in this 953C had to check in SIS. Cooler is similar to those in the old Detroits I've worked on. Does look like it could be a bit fussy to get on right what with gaskets and orings. I'd be pulling the cooler and do a real good pressure test even going to the work of heating the water it is submerged in to see if a weak seam opens up when hot. That much oil is going to be a challenge to clean out from my experience with a 988H! I might be tempted to remove and disassemble the radiator to clean it inside. Other idea would be to hook a water hose to say a heater line and push water into the system with the cap off to push the oil out the top, oil floats on water so it will go to the top.Would be messy but trying to get it out by flushing with dish washer soap can take several repeated flushes. BTDT!
A couple of comments. Thanks to the OP for the answer about the oil BTW. 1. Has anyone pressure-tested the cooling system..? 2. To get the oil out of the rad I agree with Ken. Put a hose in the top and gently fill the rad with water. Most of the oil ought to float out of the top and with a good handful of shop towels it ought to be possible to catch the worst of it as it comes out the top. Probably a 2-man job. Yes it will be a bit messy but what can you do..? To get the rest of the oil out first drain the coolant and refill with clean water. Then put a good handful of non-foaming dishwasher detergent like Cascade in through the radiator filler and run the engine hard for at least a couple of hours with the cap on. Drain and fill with clean water the inside of the radiator for any traces of oil. Repeat with the Cascade if necessary then flush again. Once the rad appears clean internally flush again a couple of times before filling with coolant.
"Update" Some additional information. They flushed the cooling system numerous times, put all new hoses on, as they were concerned that some of the oil would remain in the hoses, and or around where the clamps are attached. The shop foreman (who is a certified Cat tech) talked to numerous other Cat techs, and everyone was in agreement on it being the oil cooler. They put everything back together and I ran it yesterday for 8 hours straight pushing out trees. So it was worked hard. After shutting it down at the end of the day, I checked the radiator. There were, what I would call "little clouds" of dark stuff floating to the surface. The coolant level was the same, as with the engine oil level. I've not had the opportunity today to go back and check it, as to the weather being bad. The machine ran perfect, never so much as missed or hesitated not even one time, and had tons of power. If I can get it to attach, here is the engine oil sample result.
Did they flush it with detergent or just with water..? How long did they run it with the detergent in it..? I've run engines up to 8 hours with detergent in them with no ill effects. The analysis result you posted above. At what point in the diagnostic chain of events was that sample taken...? IMHO a cooler failure would no doubt give oil in the radiator - obviously as engine oil pressure is high than cooloing system pressure. However when a hot engine is shut down there is no oil pressure therefore the 10psi or so of pressure in the hot cooling system should force enough coolant into the oil to register a "trace" of glycol even if the sample tests negative for the presence of water.
Cascade dishwashing soap had a Caterpillar part number at one time. My dealer did anyway, not sure if it was global. Found it: part #269-1948
Nige, They ran it all night long for two nights in a row with cascade. So for over 16 hours total run time with cascade. They flushed it numerous times with cascade and water both. Matter of fact, when you take the radiator cap off, you can still smell the cascade. The oil sample was taken before the the flushing process started, it was the oil that had been in it for a while. I had them drop all fluids and put in new Cat fluids and filters. I agree with you on the different pressures, oil vs coolant and I asked them that same question about why there was no cross contamination. The tech felt it was more than likely an O ring failure vs a cooler failure and the O rings were just weak enough to allow the oil through but not the coolant. I'm gonna run it for a while then pull an antifreeze and another oil sample and send them in. It's gonna be interesting to see how the coolant looks when I get back out there. Hopefully it will be ok. When there is fuel in the coolant, what does it look like? I asked them about the injector cups leaking and the tech said the stuff in the radiator was definitely oil.
You can usually tell if there's fuel in the coolant just by the smell. If you remove the rad cap when it's warm, due to the heat the diesel smell is very strong. I wouldn't get too stressed about little blobs of oil just yet. It can take many flushes to clean out a badly contaminated system.
Agree on that! I can't remember how many times we flushed the system on the 988H that failed the cooler. Several times I would have the loader come in the shop at the end of the shift and open the drain valve and let it set all night or even over the weekend. It took several months before the sight glass would stay clean in the top tank. If I was to do this again I would do as I suggested to remove an heater hose and push the water up hill and out of the radiator cap. I think there was so much oil in the system draining it out the bottom just coated everything in the cooling system making it near impossible to remove.
I've done a similar thing in connecting a hose to the radiator drain valve and pushing water into the system from the bottom to push the oil in the radiator out of the top cap. I agree with you, the oil coats the inside of everything as it drains out from the bottom, leaving all that oil still in the system the next time it's filled up.
That would work even better than the idea of the heater hose! Would not loose any water hooking it up and shut up valve is right there already.
Final update, It appears the oil cooler or the O rings were the culprit. I have ran it several hours now with no significant loss of oil or any additional coolant contamination. Thanks for the help!