does it really matter?

Not open for further replies.
May 18, 2004
more and more i am realizing that what oil you have in your vehicle doesnt really matter. for instance, the other day when my buddies cummins came apart, there aint an oil on the planet that will stop a rod from snapping or from the rod bolt breaking. the broken rod then proceeded to punch two holes in the block that i could stick my fist through. this engine had rotella from day one and lived to 175,000 miles. schaeffers or amsoil wouldnt have prevented this from happening.
I just read about somone that got runover and killed crossing the road, so there's obviously no reason to take care of your health either.
Without oil improvments and additives as the years go on(i.e. from the days of straight mineral oil), the engine would have sludged up before it reached 175k miles. Engines fail for a number of different reasons, many because of valve train wear, loss of compression due to cylinder/piston(or piston ring)wear, damage due to overheating, simple neglect, crankcase contamination, damage from a car crash.... the list goes on What was the cause of the rod snapping? Was the engine knocking before this event occured? If so, the owner of the vehicle had fair warning and should have had it fixed because the result of not fixing it is very clear. Generally, engines fail because the parts inside wear out due to friction common to an engine. The better performing the oil the better control of the wear and longer theoretical life. Granted many people have other components wear out first, from suporting parts of the engine such as the fuel pump, computer components, etc. or the transmission fails. Some cars will run great until the day that they rust so bad that the body literally can't support it's own weight(happened to two of my friends, one more than half of the floor rusted through and the other the supporting frame around the suspension rusted and caved in at 367k miles. Just think about this though: If you thought that all engines were going to fail by having the rod snap like you say, then most people probably wouldn't care, but engines generally last longer than 175k miles these days(especially diesels), and as I feel bad that your buddies engine blew at a modest mileage, there are other ways that engines fail.
At work my company loses a couple of tractor Cat engines a year when they are left running and snow gets blown into the airboxes. The vacume increases and oil is burned through the breather mechanism... what happens next is not pretty, the rear most rod bearing fails and as the other cylinders continue to run at idle the rod is tossed about kknocking holes in the block. Until the engine siezes. Not cheap but sometimes when a winter storm hits the truck cannot be safely reached to shut it down. Could a better oil prevent this ? Nope. But we use good quality oil in these tractors anyhow. Sometimes failures occur that are beyond practical control. Other times we have Tractors in service for 20+ years. Quality lubricants is an investment towards long engine life. Like all investments we are not always gonna win.
Originally posted by Mike242GT: Get a lot of snow down there in Corpus Christi, do you?
6" last Christmas actually.....
Things break, even good things. When checking into one park a ranger commented that he use to have a Dodge with a Cummins, but a bit over 100k the bolts on a cam sprocket sheared, making quite a mess of things. It was too expensive for him to have it rebuilt, a mechanic bought it, rebuilt, and he said was still driving it many years later. Also one will see more and more diesels break down early as 'chips' are very popular. For a few hundred bucks you can get quite a power boost, 50 to 100 hp is common, more if you want it, which is fun until something breaks.
the cause was determined to be one of the rod bolts broke. im sure by not changin the oil it wouldnt have made it to 175000 miles, but you cant tell me that by runnin amsoil or redline or any other oil that is expensive as heck over rotella would have saved this from happening. what does 'Impermanence' mean?
Originally posted by kenw:
Originally posted by Mike242GT: Get a lot of snow down there in Corpus Christi, do you?
6" last Christmas actually.....

Wow! 6 inches is nothing. My 2wd Vibe has no problem with that much.
I have cable TV - 6 inches is nothing! Rod bolts generally break from high RPM - the load on them is on the exhaust stroke, at TDC at high RPMs, from the inertia of the piston/rod assembly going up.
Was your buddy's truck bombed? What was he / it doing at time of failure? RPM's? Boost? HP level? Torque level? Dyanoed? Many guys on TDR have 100,000 200,000 300,000 400,000 miles on theirs. I have only 55k on mine, but plan for 500k + and I tow heavy. Interesting, I would like to know more about the conditions and circumstances of the truck before the rod break. Bob Weis
I have to agree with RWeis - about the only way a Cummins rod can blow a bolt would be if it was bombed and really pushing the RPMs and boost. If the engine was stock than it might be a one in a million type of things.
Yes it matters! In your example it really does not matter but ingeneral it does. Do you realise how seldom an engine is taken out by a breaking rod bolt????? Outside of raceing and hard core off roading you almost never hear of someone loseing an engine due to sheared rod bolt!!! A lot of people have sludged engine from either cheap oil,over extended OCI etc. A lot of people have oil burners due to cheaply made CAFE oil and poor design. A lot of people have issues with early bearing wear from the above as well. The main failure iteams in an engine are oil pump,bearings,cam's,valves and rings!! All of these items are affected by the type of oil you use and the OCI! None of the nuts or bolts on a vechile are affected directly by the oil!
Even high rev'ed or or very hard worked engines that "spin" a bearing would benefit from better oil. The better oil might have a higher film strength that prevents metal to metal contact, the bearing seizing to the journal, and the subsequent spinning of the bearing. (Bearings don't spin until after the bearing seizes to the journal.) Ken
Years ago we celebrated when an engine made it to 100,000 miles. I just rebuilt one ov my Toyta diesels at close to 500,000 miles. Would have made more if it had not been for breaks in the air intake twice that allowed large amounts of dirt into the engine. Engines fail for numerous reasons. I've been part of the team that analized two Nissan engines that failed under warrantee. High bearing wear (at 25,000 miles) was determined during that analisis. The oil was an Argentine 15W-40. Checks of additional pickups of the same fleet with the same oil also showed high bearing wear, where the same engine with Delo and another US 15W-40 did not.
I fully concur about using good oil, if the engine is a reliable one to start with, you can extend its life beyond expectations and thereby your investment in oil pays off quite handsomely. I had a Accord V6 go over 500,000 miles with Mobil-I, my OM616 engines have lasted over 500,000 with ease, all I did was put either Delvac Super or Delo400, air filter is truly a critical aspect in dusty conditions, so is cooling system maintenance in especially extended temp conditions.
FWIW, My father-in-law is an owner-operator OTR truck driver. He has a 2002 or 2003 Peterbilt with 750,000 miles on it's Caterpillar engine. He usually puts around 1 million miles on a truck, then trades it in on a new one. He uses Mobil Delvac 1300 & Lucas heavy duty oil stabilizer in his truck. He told me last week that he used to like Rotella, but for some reason, his Peterbilt consumes Rotella at approx. twice the rate of Delvac. I know the Lucas oil stabilizer thing might suprise a lot of you, since it is a product that is generally frowned upon here at BITOG. But, my father-in-law has used the stuff for the better part of 20 years in his big rigs & has never had a lubrication-related engine problem. He has gallons upon gallons of the stuff in his garage. I've been tempted to "experiment" with it. [Wink]
gets me thinking of the "healthy non-smoking jogger who gets hit by a bus who's driver smokes 2.5 packs a day." -Dennis Leary
Not open for further replies.

Similar threads