Engine/Transmission (1998.5 - 2002) Another Oil Question

[DocStressor]

Amsoil 5W-30 is a good product and it is well documented that it works well in the Cummins. Numerous oil analyses and Wayne's long term "experiment" will back that up. While it is technically a 30 weight, it is formulated to the high end of that viscosity range and it is very shear resistant. Remember that the Cummins is designed to use 40 weight conventional oil. Over the long haul, conventional 40 weight can shear down to a 30 weight viscosity. So I would imagine that the engineers would have taken that into consideration when designing the engine. Also, remember that our engine is rated for something like 60,000 lb CGVW. At 20,000 lb or so we are never really pushing the load bearing limits of a 40 weight oil anyway. If we were talking about a tractor or a boat, I’d say stick with a 40 weight.



My only reservation about Amsoil 5W-30 is cost effectiveness. If you are not heavily modified, drive moderately, and use a bypass filter, it makes some sense if you use extended drain intervals. But at your hp level, you are likely accumulating a lot of soot, which probably excludes extending the drain interval much beyond what you are doing now (only oil analysis will let you know this for sure). You really don't have winter where you live, so the 15W-40 would make more sense year round. It costs a bunch less than the 5W-40 and from everything I have seen posted on this and other sites, protects as well or better than the 5W-30. I use the stuff year round in Reno where it does get pretty cold. The only thing you might give up with the heavier oil is a tiny bit of performance/mileage because of the higher viscosity.

 

[jboehm]

Castrol 15/40 Used to be DieselAll40... good here in the midwest... must make sure youre getting the diesel rated stuff. Gotta a good parts store down the steet. plus some parts guys that know what they're talking about. !!!!!

 

[15w40]

After reading this thread on motor oil, I came across some info published by Bosch on lubricants. They have a graph showing viscosity vs. temperature for multigrade oils. The viscosity is in units of mm^2/s which is the same as centistokes as mentioned by amsoilman, and he is correct in saying that at operating temperatures there is almost no difference in the oil viscosity.



#ad




Where a synthetic 5W-40 makes a real difference is in cold starting in artic conditions. Other than that a 15W-40 should work well.

 

[John Berger]

It's been awhile since this post was started, but I wanted to add an observation. Wayne(amsoilman) suggested waiting 5-6 hours before checking the oil level. I checked my oil one afternoon last week and the oil level was low, about halfway between the lines on the stick. I checked the oil over a time span of an hour and a half and it gradually crept up the dipstick the longer the truck sat. Why such a long time to drain back to the pan?

 

[pkennedy]

It will take the last 1-2 quarts of oil longer to drain back because the are sitting in the flatter areas of the head, cam gallery and block. Best time to check oil is always before start up each day as adequate drainage times will be more Consistant, oil levels will never be consistant as we are not as fussy to the exact amount of drain down time while performing other tasks throughout the day. Also as engine oil starts to get dirty consumption will increase, example is 3406 Cat on average 8000miles on level, at 10000 miles down 1-1. 5 Gal. change oil with dino. Synthetic I found is different when down 2 Gals. change filters and top up and send in oil analysis ( approx 25000 miles on 425/3406- complete oil change at 100,000 ) this engine is still consistant at 710,000 miles as are lab tests. This unit has been on A#%*^@ synthetic since 90,000 miles (10-40 ) never been apart 2 valve sets something is going right. PK

 

[John Berger]

I still think I'm losing oil somewhere, but the only place I ever see wet oil is at the blowby tube and on the power steering unit which is right by the bottom of the tube. My oil analysis was good for wear metals. I checked the turbo blades and the intercooler tubes, and there is no oil residue. The block is dry as well as the oil pan, the filter and every gasket area. I can detect no oil residue at the exhaust pipe and I don't see excessive smoke while driving. There is no spray under the bumper or on the 5'ver when I tow. What confounds me is that this just started this past summer. The only thing I can think of is the truck was not properly broke in, but this makes no sense, since I didn't go to synthetics until close to 50K miles. This problem started after 70K miles. I'm perplexed. This only seems to happen when I tow or make a long trip. If I have to live with this, I am seriously going to consider going to Rotella or another non-synthetic and changing every 4K. I love the Amsoil, but it's too expensive to be adding makeup oil every 1-2K miles.

 

[pkennedy]

You may want to check and see if you are getting oil in the cooling system, look and see if there are oil globs in anti-freeze in radiator tank and overflow tank. If this is happening you may have a couple of different problems, my 91 developed a crack in the oil cooler also cracked heads and head gaskets can cause this condition. Does this happen only when towing trailer or running empty, you may not see it coming out the tailpipe with a broken ring or valve seal but the soot in tailpipe will be oily. PK

 

[John Berger]

The soot at the tailpipe is, well, sooty. Not oily. I haven't noticed oil in the anti-freeze, but I will check that again. I would have thought the oil analysis would pick up anti-freeze. If oil can get mixed with the anti-freeze, anti-freeze should be showing up in the oil as well, shouldn't it? I first noticed it when towing, but it could be a constant thing.

 

[fest3er]

Originally posted by John Berger

The soot at the tailpipe is, well, sooty. Not oily. I haven't noticed oil in the anti-freeze, but I will check that again. I would have thought the oil analysis would pick up anti-freeze. If oil can get mixed with the anti-freeze, anti-freeze should be showing up in the oil as well, shouldn't it? I first noticed it when towing, but it could be a constant thing.

If the oil pressure is always greater than the coolant pressure, there would be one-way flow - oil into the coolant. If the oil cooler (inside, behind the filter mount) has sprung a leak, I might expect oil in the coolant, but not vice versa. But then, if it's a bad-enough leak, you'll lose all your oil real fast - it will displace the coolant, which will blow out the overflow tank.



Fest3er

 

[pkennedy]

John the oil will be in the rad because as stated oil psi is higher Iam wondering after putting in the synthetic do you baby it more or did you get it hot you said you pull a trailer. Do you use any kind of fuel conditioner, possibility that if you had shut your truck down a little to warm on dino oil after pulling the oiling ring may have some coked oil (hard carbon) and the synthetic will bypass a bit. Normally this will show up at the tailpipe like I said but I have seen NTC 855 Cummins do this, it is odd to use that much oil all of a sudden. Hot shut downs are deadly on diesels and everybody talks about there turbos coking, have not heard of this to much on Cummins B&C's. Engines with one piece heads are bad which we have but most common on B's are the exhaust manifolds warping, these engines will take a lot of heat but don't be stingy on cool down ( min 3-5 minutes ) after pulling. I would put some thought into all this before dumping oil or taking anything apart, some base oils are extremely bad for varnish as well and can cause oil usage until it is all burned out (2-5 oil changes). Some of this should have shown up in oil analysis but it not a guarantee synthetic will not show heat breakdown until 400F. PK

 

[MxerChris]

OK, I know this my be off the general theme of this thread, but I noticed that one of the guys stated that after putting in the correct amount as specified in the manual (11qts. I think) the stick read over full, I noticed this when I bought my truck used and the dealer changed the oil, so I guess my question is how much oil do you put in, what the manual says or to the full mark on the dipstick?

 

[John Berger]

You put in 11 quarts. Some dipsticks were notched and would read high. My oil level always read high. I never bothered with the fix. I just referenced the high point.



pkennedy, I see your point. Yes, I do use fuel conditioner, and in every tankful. I have not babied the engine, nor have I abused it. I always watch the pyro after a long hot run and don't shut down until it reads 300 or lower. There is no oil in the anti-freeze in the radiator or overflow tank.

 

[pkennedy]

John I figured this was the case and all I would recommend is drive it under load as much as possible so if there is anything gumming up the rings it will burn it off. Also if you end up going back to dino use a series 3 diesel oil which is high detergent and this can simulate a same condition of high oil consumption but will also wash the garbage out. If your consumption continues there is a possibility of scored cylinders, not sure how it might of happened if this is true. PK

 

[John Berger]

Series 3 Diesel oil? What are some brands? Scored cylinder, huh? Well, that would be hard to convince someone to correct. I've never run excessive EGT's, which is the first thought that comes to mind. I think the highest I ever saw was 1250 pulling a grade a couple of years ago. And that did not last long. I am assuming oil analysis would not pick that up. Analysis indicates everything in the engine is fine. The truck runs great and pulls strongly. I guess I'll keep monitoring it and see where it goes.



One other note: I've done an extensive amount of towing since April. Total driven miles near 15K. A good part of that mileage, close to half, was towing.

 

[pkennedy]

Sorry John series 3 oils are Shell Rotella T, Esso XD3, Chevron Delo 400 and by looking at the specs on containers you will see the advanced C Ratings CH,CI,CI 2 etc. They should say on them in the discription high detergent or advanced cleaners, please note not all oils with same rating use the same cleaners, lubricating inhansers or base stocks and will produce different levels of oil usage and color after run a while. This is true of synthetics as well hence the oil in your engine now will probably stabilize in time, this is why we all should be patient. Cylinder scoring is normally related to overworking the engine when it is to cold but NTC 855 Cummins were famous for this especially in company trucks where they were left idling in the summer to run A/C units. In the summer watch in a truck stop and you will see trucks idling driver will jump in and hammer on it and a big puff of grey/blue smoke will come out the stack, right at this point it is very possible to score a cylinder. Dont panic I am not saying this is your problem but I cringe every time my trucks go to any place that lets someone other than me start it or drive it the possibilities are endless, remember they dont own a frigin nickel in it including D/C. PK

 

[John Berger]

I don't think cylinder scoring is the problem. I haven't done anything to the truck such as you described. I'm going to monitor this situation and see where it goes. I'm towing the next two weekends, so we'll see.