Engine/Transmission (1998.5 - 2002) Injector/oil leak question

[John Berger]

I was talking to a mechanic last night and he said that my disappearing oil problem, could be due to the injectors and too much fuel. I don't buy that because I would expect to see fuel in the oil and the last oil analysis came back with excellant readings all across the board. Am I correct in this assumption? This guy is a CTD owner, by the way. I still think it's blowby and I can find no other place that the oil is going. I've been running Amsoil 15W-40 since 45K miles. This oil disappearing act started this past April. I think I'm gonna stop at the truck stop tonight and pick up some Rotella. I'm kind of throwing things at the wall right now to see what sticks.



I've done extensive towing this past 6 months. Is it possible after all this time that my engine was/is not broke in? It has 86,100 miles on it right now.

 

[redram]

Maybe I missed something but where did you give any particulars?

How much oil comsumption over 1000 miles?

Only when towing?

At what rpm / speed?

Do you have any mods to the engine?



45,000 is more than enough to "break-in" a 24 valve ISB.

What type of drain intervals?

What length between oil filter changes?



Where and how did you obtian the oil sample?

Fuel and oil (even synthetic oils) are both hydrocarbons and depending on the method of sampling you may or may not have seen excessive fuel on the sample. How many oil samples have you taken over the 40K miles that you have been using the Amsoil? if it's only one, at what mileage was it sampled at on the truck and number miles on the oil cahnge?



What has your fuel mileage been doing? Do you track it every tank? Has it varied?



Okay, I think I've asked about twenty questions?Oo. Oo.

 

[John Berger]

redram, I've posted most of that stuff already. I was trying to avoid redundancy. I've got RV injectors and an EZ box. I've been running 10K drain intervals, with filter changes at 5K. I've used Fleetguard and Amsoil oil filters. Blackstone labs did the samples on the oil. Last one done at 80,728 miles. I've done 4 oil samples over the 40K miles on the sample. My fuel mileage has improved while towing. Some of that was the new clutch (less drag on the drivetrain, than the stock clutch which grenaded on me in May), slowing down just a bit and ditching cruise control on long hauls. My fuel mileage unloaded has more or less been fairly consistent around here. Varies from 15. 8 to 16. 9 mpg, which is pretty much the case since I had the truck. Occasionally I'll foray into the low 17's, but I haven't seen numbers like that since I put the injectors and box on. And as far as I can tell, this problem didn't start until early this past spring. And only when I tow. The blowby is much more considerable after a tow. I would guess the use is about a quart every 2-3K, if I've towed most of that. I have checked everything that has been suggested in previous posts, from the turbo to the exhaust. There is absolutely no trace of oil in the coolant or anywhere on the engine or transmission. Hope that answers your questions.

 

[redram]

John,



If you want, I'd take a look at your oil analysis data to see if anything can be gleaned from this data.



I am a Mechanical Engineer working for an oil company as Technical Services Manager, a STLE member and certified OMA (Oil Monitoring Analyst).



I have owned a Cummins pickup for 12+ years.



Oil consumption is usually a function of one of the following cases:

-leaks from gaskets in the valve covers, pan, front / rear main seals

-valve guide seal degradation (typical of oil smoke on initial startup, anything over a qt/1000 is getting marginal and time to replace the valve stem seals)

-oil control rings allowing oil into the combustion chambers (causing smoke on heavy loading / hard acceleration) Caused by broken rings, tensiled rings, carbon / soot buildup in the ring grooves, scoring / scratching on the cylinder bores (liner bores)

-emissions related systems (pcv, egr, etc

-turbocharger oil seals (leaks on the inlet pressurised side causing oil on the intake side or hot side leaks resulting in oil on the downpipe)

- on diesels, worn valves / valves out of adjustment could result in over pressured crankcase which results in oil being blowout of the crankcase vent / vent tube.



Using a qt per 2-3K miles of heavy towing at high speeds and loads may be normal / may not be normal depending on the mods on your truck. Unmodified trucks towing at 65 mph pulling 10,000 lb trailers probably use a qt or oil every 3000-5000 miles on average. So yours, having some mods increasing fueling, resulting in more fuel to try and wash off the oil film on the cylinder walls, creating higher pressures causing a stronger scraping load of the ring to the cylinder wall (further trying to scrape the oil film from the cylinder walls) may be normal at 2000-3000 miles.



Send me the oil analysis - I'll take a look at them and verify that all appears normal.

 

[Mark_Kendrick]

Originally posted by John Berger

... And as far as I can tell, this problem didn't start until early this past spring. And only when I tow. The blowby is much more considerable after a tow. I would guess the use is about a quart every 2-3K, ...

The oil is probably exiting in the 'puke' tube.



I found something interesting when I blew a headgasket. I took the head down and had it ported and o-ringed.



The machine shop found that the exhaust valves were worn about . 003" at 55kmi. the guides were still pretty true. I had them replace the exhaust valves and put ne seals on all valves. I don't know if it helped yet but I was alarmed at that wear. The new valves were ~$110 from cummins. The intake side looked fine.



The valve train and the condition of the bowls on the 24v are VERY cheesy.



FWIW,

Mark

 

[LSMITH]

John, you need to adjust your valves just to get that out of the way, takes an hour and is free. Insufficient lash will pressurize the crankcase and blow the oil out as mentioned, the harder you run it the more it will blow out too.



Some of these trucks use a quart every 3-5K and are in good working order. I would not get too bent out of shape about it, just keep an eye on it.

 

[John Berger]

LSMITH, that wouldn't surprise me. Redram, thanks for the offer. I'll pm the analysis later on today. Thanks for all the input. The only action I might take is switching back to Dino lube, probably Rotella or Valvoline. If I'm gonna use oil, I don't want to throw as much money out the tube, if you know what I mean.

 

[redram]

Don't be too hard on"synthetics" based only on experience with one brand. Just like 'dino oils' are not all created equal neither are "high performance oils" / synthetics.



I've been using Royal Purple for ten plus years and have not had to add more than a quart in 10,000 -12,000 miles over 300K on two different trucks. That was with 12,000 average oil change intervals.



I wouldn't call investing $5. 00 per 5000 miles alot of money thrown away on your truck. That's pretty cheap "insurance" on getting better performance.



If your problem is not mechanical and it is related to the oil, then changing to another brand might give you different performance.



Check the mechanical things first - that's where your oil consumption problems are 95% likely to be.

 

[John Berger]

Good point. I just don't like throwing money away. Did you get my e-mail?