Engine not "broke in" properly...?

[Douglas]

In the City, I drive a street sweeper. It's a 1999 cabover Ford Model truck, with a 190 hp diesel engine, (don't know what size truck), and the engine is weak as ****e!!! When you sweep, the engine spends most of the day idling, at speeds of no more than 5 mph. They say the engine is so weak because it's been idled or drivien thru town most of it's life and it's never been out on the road (It's been years since the truck even hit 55 mph!)

When driving (not sweeping) you can floor the gas pedal and it will still take a few seconds for the engine to rev up and start pulling itself to accelerate. Down a hill, 45 mph is about wide open, and to drive any faster would probably blow it up, and up a hill, you probably won't even be able to reach over 30 mph. Also it runs hot! While it's idling, the engine temp stays at about 180 degrees F. But when driving thru town it begins to heat up to about 210 and eventually 220 degrees! :shock: (You would think it would be the exact opposite...) When it was new, they say it used to have a pretty good bit of power, just like a regular engine should. (I never drove it when it was new), but now it's wore out because it was never 'broke in' right.

So, my question is, what causes an engine to get weak like this if it's never out on the road any? And could it be fixed (other than getting a new engine/transmission?)

Oh, there's one more weird thing. Although when driving thru town and you've got your foot on the gas pedal, the machine feels like it's got a giant invisible hand pushing it back, until you let your foot off the accelerator. Then you'll find that it will coast,.. and coast and coast and coast. In fact on a downgrade you can save lots of fuel because it will run just as fast coasting at idel as it will if you had your foot on the gas pedal.

[allan5oh]

mechanical issue, not break in.

Possibly a head gasket.

[Douglas]

Hmm, it's been running weak like this for a few years now. Is there any way to tell if it's a head gasket? (Something I can look at to tell?) Thanks

(Note: I don't really plan on fixing the problem, I had just always wondered what caused it, but I might can tell the shop and see if they'll replace it, but they may not because we're about to get a new sweeper.)

[allan5oh]

contamination in oil/coolant. White smoke out of exhaust. bubbling in coolant.

Has anyone ever ran any codes on it? I would check that first.