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Design observations on V-10
A few things I have noticed about my Y2K 6.8 that I would like to share and invite comment on:
There is no EGR System (Exhaust gas recirculation). No tube going from the exhaust manifold, no valve- nothing. I noticed that the 1999 model does have one. This is the first gas engine made in the last 20 years that I have seen without an EGR System.
The engine exhibits very good compression for braking. I think that most modern engines feed gas during deceleration to reduce emissions, thus reducing braking compression and efficiency. This does not seem to happen at least to the same degree on my 6.8. I notice excellent braking compression especially below 2000 RPM. I also noticed that during deceleration, that the exhaust sounds like the older engines with a hint of backfire on long hills and that pup puf pup sound that I hear from our ’69 F250 when going down a hill in low gear. I suspect that this also due to the engine not feeding gas during deceleration. I view this as a very positive thing.
The engine has an oil cooler but I question its efficiency. It has tubes that come from the lower radiator hose back to the “Cooler” which is just above the oil filter. The cooler is enclosed so I can’t see how it works inside, but I doubt it could do very much. I would rather see a conventional “tube and fin” cooler. Has anybody ever looked inside our stock coolers to see how they work? I suppose considering that a lot of gas engines have no separate coolers, ours is still a step ahead but I don’t think it is a “Super Duty” cooler.
Yeah is does make a few noises I am not used to hearing. All the noises it makes while driving I consider normal and they do not bother me. With Texaco gas, when climbing hills if I quickly move the accelerator from mild acceleration to heavy, it pings for an instant before the knock sensor kicks in and retards the timing. This I believe is just as it should work. This does not happen on Chevron gas. I always burn regular. The engine is loud in general, louder at certain rpms and sounds very powerful. I think this is due to its wide-V design and intake system. I have the noise from the Y pipe but it is not too offensive. I will probably replace the Y when somebody comes up with an easy fix, and the warranty is expired (I drive 36k a year so that won’t take long).
The one noise that I do find offensive on my 6.8 I have not heard anybody else describe so it is probably an isolated problem. It has a rattle sound that sounds like a bad water pump that appears to be coming from the top left of the engine and somewhat toward the rear. It can be heard when idling or revving to about 1300 rpm but does not change when the rpm changes. You can not hear it when driving so it is separate from the infamous “Flutter”. It can be heard from inside the cab or under the hood, but not so well from under the truck. Seams more noticeable when the truck has warmed up and the oil is warm. I tracked down the noise further with an engine stethoscope and it is definitely a rattley knock coming from the top rear of the left head. I am guessing valve or cam related. Of course the dealer says its “normal” so no help there. It was pretty loud when the engine was new but is less now with 15k miles. I switched to synthetic oil and that masked it to the point that you would have to know what to listen for to hear it. Before the warranty runs out I plan to pull the valve cover to find the problem and make the dealer fix it.
Any comments to these or other V-10 design issues would be interesting discussion.
Thanks!
Dean
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2000 F250 Lariat SC 4WD, 158"WB , 373reg, 6.8, 5 Spd, Camper Pkg, ESOF, Woodland Green, Born 4/00 @ the Kentucky Truck Plant
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2000 F250 Lariat SC 4WD, 158"WB, 373reg, 6.8, 5 Spd, Camper Pkg, ESOF, Woodland Green, Ordered 7/99, Born 4/00 @ the Kentucky Truck Plant
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