Engine/Transmission (1994 - 1998) New To Grease Burners..

[onstottc]

Although I am a fairly accomplished shade-tree mechanic. (Built the straigt six in my Jaguar from several boxes of parts)



My new old 1995 Ram is my very first Diesel. I've got a few basic questions...



On a gasoline engine, I'm fairly good at identifying problems by the sounds coming from the engine. Not sure what I should listen for on a diesel. If it was a gas engine, I'd swear I had a detonation problem



Why are the exhaust pipes so big? I understand that diesels vary the amount of fuel to increase the speed. . I'd love to find a book that explains diesel induction in depth.



At 211,000 miles should I do any PM on the engine? Rod/ big end bearings? Valve Job? Others? I know about the KDP fix and will probably get around to fixing that soon.



Well, I'm on my way to the parts store to pick up a set of sparkplugs and a throttle butterfly for the carb...

 

[JoeBioDiesel]

Hello, and welcome to the forums.

When you replace the injectors with the spark plugs (I hope you're using Champions) you will notice the engine gets much quieter, cranks longer, and cures that terrible detonation problem you have.



You shouldn't need any internal engine work unless it has been neglected, or suffers an unusual failure.

Good luck with your new ride... .



Joe

 

[rrausch]

Welcome to the TDR!



I loved those old Jag 6's! Hemi head and overhead cams indeed! And didn't you love packing those rear outboard reduction boxes with grease every oil change! Ha! I restored a 1976 XJ12 for my girlfriend many years ago--different engine than the 6 but still nice.



Ok... with 211,000 miles on your '95 she is still a youngster! But I would Kill that DP pronto! You don't want to see what a lost Dowel Pin can do to the engine! It ain't pretty! You can get on the list in your area for the KDP kit which contains all you need to neutralize it. Or you can do the tab method.



As near as I can figure, the sound my '95 12-Valve makes idling must be coming from the fuel being pumped out of the injectors at about 17,500 Pounds per Square Inch pressure! Amazing huh! That is how much pressure our P7100 injection pumps make, and to do that they need extremely small tolerances. Hence the use of a GOOD diesel fuel filter! Because you don't want ANY leetle particle of dirt causing scoring in the pump. And yes, change the fuel filter every other oil change--about 12,000 miles. You can get them cheap at Geno's.



The exhaust pipes are so big because diesels flow a LOT of air, and also in order to cool these babies down quickly! As you know, diesels can burn a lot of fuel relative to the amount of air, and under full-load conditions, (especially if you have a bombed plate) the conditions inside the cylinders begin to look like a blowtorch. Combustion temps of above 1300 degrees tend to melt pistons--ouch! By looking at my pyrometer, it takes up to 4-5 minutes for the exhaust manifold to cool down from 900 degrees to 300. That is important because the Turbo bearings run in engine oil, and if the engine is shut down when the pyro temp is above 300 degrees, the oil tends to cook in the bearing sleeve and cause coking, which tears the shaft/bearing up. Turbo failure is another expensive little item which you don't want to know about!



Cummins used to say that these engines should have the rod bearings R&R'd at 300,000 miles, but I haven't read that in awhile. Maybe somebody else knows about that.

 

[Deezul1]

I have read several articles about 12 valve engines that have well over 1,000,000 miles on them and never had the head off. These were hotshotters delivering travel trailers so were working most of the time. One of these stories was published in the TDR magazine. With good oil and timely changes 200,000 is nothing to worry about.

Welcome to the group.

John