Generator question
I’m thinking I know the answer but still have to look at the owners manual. Just got back from our first trip. Cummins Onan 5500 gas generator. The trip there was no problem. Generator ran fine the en...
Forum Discussion
dodge guy,
We have an Onan 7000. It is (was) VERY sensitive to oil level. What I discovered while travelling during the summer (only when temps were mid 80's and above), is that the our generator would shut down for no reason, but then restart right afterward. This would especially happen if we hit a big dip or bump in the road, or a mis-aligned expansion joint. I believe I was running 10W-30 or 10W-40 at the time as according to the chart, that was good to 100*, which is very rare here in the Northeast, but also protected down to about 0*, which was good because we sometimes camp into the late Fall or early Spring. I noticed this problem would happen occasionally if the oil was topped off full, but would happen more frequently as the oil level went down, though still well within the cross-hatch markings on the dipstick.
Looking at the oil chart, I noticed they do spec straight SAE-30 weight oil for use above 32*. On a hunch, I thought that maybe it had something to do with the multiviscosity oils. (I figured maybe the oil wasn't getting quite hot enough so it would act like a 30 or 40 weight. I looked at viscosity vs. temp charts and there didn't seem to be a huge difference in the 40*C - 50*C range, but I figured, "What the heck?". I did noticed that the density of the straight 30W seemed to be consistently higher than the multi-vis oils at any given temp.) Anyway, I put straight SAE-30 in it and have not had the problem since. I DO make sure the oil is always topped off before a trip. Mostly because adding oil is a real pain, and this way I only have to add a couple of ounces at a time, and not too much of a problem. We have been camping when it's been down in the mid to upper 20's, and the generator still started OK. I guess if I was going to really brave the cold, I'd switch to the 5W-30 recommendation for that trip, but honestly, we don't really do that type of camping lately.
So, if you're not using straight SAE-30 weight oil, give that a shot, see if the condition improves any.
Good Luck,
~Rick
We have an Onan 7000. It is (was) VERY sensitive to oil level. What I discovered while travelling during the summer (only when temps were mid 80's and above), is that the our generator would shut down for no reason, but then restart right afterward. This would especially happen if we hit a big dip or bump in the road, or a mis-aligned expansion joint. I believe I was running 10W-30 or 10W-40 at the time as according to the chart, that was good to 100*, which is very rare here in the Northeast, but also protected down to about 0*, which was good because we sometimes camp into the late Fall or early Spring. I noticed this problem would happen occasionally if the oil was topped off full, but would happen more frequently as the oil level went down, though still well within the cross-hatch markings on the dipstick.
Looking at the oil chart, I noticed they do spec straight SAE-30 weight oil for use above 32*. On a hunch, I thought that maybe it had something to do with the multiviscosity oils. (I figured maybe the oil wasn't getting quite hot enough so it would act like a 30 or 40 weight. I looked at viscosity vs. temp charts and there didn't seem to be a huge difference in the 40*C - 50*C range, but I figured, "What the heck?". I did noticed that the density of the straight 30W seemed to be consistently higher than the multi-vis oils at any given temp.) Anyway, I put straight SAE-30 in it and have not had the problem since. I DO make sure the oil is always topped off before a trip. Mostly because adding oil is a real pain, and this way I only have to add a couple of ounces at a time, and not too much of a problem. We have been camping when it's been down in the mid to upper 20's, and the generator still started OK. I guess if I was going to really brave the cold, I'd switch to the 5W-30 recommendation for that trip, but honestly, we don't really do that type of camping lately.
So, if you're not using straight SAE-30 weight oil, give that a shot, see if the condition improves any.
Good Luck,
~Rick
