I have a CAT 232B2 skid steer loader & a Kubota kx141-3 excavator. I sent the engine oil of both machines to a lab for testing. The CAT skid steer oil came back all within normal limits. However the Kubota KX141 (which has just over 2500hrs) oil test results came back with 2% water & 39ppm copper. I phoned the oil company I purchase my oil from (& who also arranged the testing), & they said that the 39ppm copper was a concern & needed to be monitored, however the 2% water figure is normal. 2% water content in the oil seems rather high to me (the CAT had <1% water). Does anybody else here get their engine oil tested, & what are the typical copper & water values in the test results?
Is this the first time you sent samples for testing..? If not then how were the results from previous samples regarding water & copper..? Did the test come back positive for glycol..? You are using a glycol-based coolant I assume..? For me 2% water is about 10 times higher than I would expect for a "negative for water" analysis, even 1% is way too high for my liking. Our results were always presented in one of three classifications: - Less than 0.2% water - Negative for water Between 0.2% & 0.5% water - Trace of Water More than 0.5% water - Positive for water Regarding the copper, how many operating hours did the oil have that was sampled. If the oil had around 500 operating hours when the sample was taken then acceptable copper levels should be in single figures. 39ppm copper would make me stop the machine immediately and investigate the cause.
this is the 1st time I have sent the oil in for testing. The machines were purchased 2nd hand, & I have no idea how many hours the oil has been in the machines, though the guy I purchased the Kubota excavator from reckoned the oil had been changed only about 30 hours ago. 2% water seemed high to me as well (it was actually 2.2%), though the oil guy reckoned this was fairly normal. The CAT skid steer only had 0.1% water, not 1% as I previously wrote. Apart from the high water & copper, all the other levels seemed good. Sodium was <1 ppm, & I have read that a coolant leak normally shows up as high sodium levels.
Someone is blowing smoke up your *** if they say that 2.2% water is "fairly normal" - that's total BS. 0.1% water that was found in the Cat SS engine is in the normal range. Again depending on what type of coolant you are using a coolant leak into the oil system will show up as an increase in sodium for conventional coolant or potassium for Extended Life organic acid-based coolant. I'll repeat my question from above, what type of coolant are you using..? Did you have the coolant analyzed..? If not I suggest that you do. Maybe with unknown previous maintenance history it might be an idea to go for complete fluid changes in every compartment on the machine then go from there. To get another view on the oil analysis, take a sample and drop it into your local Cat dealer and ask for it to be analyzed.
I don't know what type of coolant is used (I presume it would be glycol based, as that is the only type sold here as far as I am aware), however potassium level is only 2ppm, so neither the sodium or potassium levels would tend to suggest a coolant leak. I haven't had the coolant analysed. The oil test is only $33.00, however for some reason testing the coolant is a lot more expensive at over $100 if I read correctly on their web site. I think I will change the oil & get it retested after 100 or so hours. I might also try the water crackle test myself to see what results I get. Could possibly have been an anomaly in the test result or something.
If the coolant test is $100 then on such a relatively small machine it might simply be better to drain the cooling system, flush with clean water a couple of times, and fill with Cat Extended Life Coolant - it's what your skid steer will have in it anyway. When you are draining check to see if what's coming out looks (or tastes) like coolant, it might be just water for all you know. If there is any trace of oil visible inside the radiator or in the coolant when you drain it then use some dishwashing machine detergent and run the system with just water in it for 30-60 minutes at operating temperature, then drain and flush well with clean water before filling with ELC. I would not change the oil yet. I'd take two samples, send one to Cat and the other to the oil company lab and see how the results pan out compared to one another.
Single oil samples rarely provide a picture of the health of your engine. They are meant to show trends over time. You need to do them on a schedule. That kind of water content is what you see in a machine that has been sitting for an extended period of time and can be normally associated with being in a wet climate. I've seen plenty of machines that set over the winter here on the west side of Washington State come up with that type of reading. Warm up the engine and then change the oil and filter. Run a hundred hours or so and then take another oil sample. I have always been concerned about copper though. It could be that an extended shutdown period and the water content caused some leaching, maybe in the rocker arm bushings. If it is associated with aluminum I would think main and rod bearings. You didn't mention it so probably not. Maybe someone here will have an idea of where that can come from on a Kubota engine.
The copper may have more to do with it being a Kubota engine. I remember I had the oil sampled on my skid steer back when it was new and it had increased copper levels but they said it was normal especially during break in. I think like anything else some oil testing facilities are better than others. I think it also depends on when you took the sample too. Was the machine up to operating temp and then the oil drawn or is was taken when the machine had been sitting for awhile. Taking another sample to Cat or another testing facility could be a good way to check if results are similar.
The machine had been used for about 2 hours just before taking the oil sample, however it had sat unused for around 4 weeks prior to taking the oil sample, & there had been heavy rain just 2 weeks before. How many hours of use would it normally take to burn off the water in the oil if the water was just from it sitting around in wet weather? I would have expected the CAT skid steer to show higher water levels if that was the case, as it had been sitting around for around the same amount of time as the Kubota in the wet weather, & it only had around 20 mins warmup before taking the sanple. I am pretty sure there is coolant in the radiator & not just water, as it is a dark green colour. I have also read that high copper levels are normal in new machinery, but after a period of time this should stabilize at below 10ppm. This machine has over 2500 hours on it. Aluminium levels in the Kubota are only 3ppm, & the CAT has 2ppm.
If the thermostat wasn't working properly or the engine was running cold could take longer to vent off water.