I bought a 1999 3500 cummins and so far it has been a nightmare. First the alternator went bad and left me stranded. Then the fuel gauge doesn't work right and I ran out of gas. Then I had to replace the lift and injection pump. Then a boost leak. And the wheel speed sensor. Now I found out about the 53 block. And that's what I have. This morning the oil pressure sensor quit working. WTF! I bought the truck 5 months ago with less than 100,000 on it and it is in beautiful shape. Dwr 3500 4x4 355 gears 4" exaust, no muffler. Also it only gets 12-13 mpgs, no tuner and I put a new big air filter on it. It does not seem to have much power at all. Very disappointed I am a Ford guy but I bought a cummins because I was told by everybody they are the most reliable. Wow was I told wrong. Is the engine block going to crack? Why are my mpgs so pathetic? What else could go wrong?

 

Slow down a minute here. First off, welcome to the site. These are the best trucks out there but they do have some inherent problems, just like everything mechanical. We can work you through all of this and it sounds like you'll have a truck that will last for years to come.

The 53 block, in most cases works just fine but we only hear about the one few that go bad. Mine has held just shy of 400hp and been worked like a dog for 200,000 miles now with no issues at all. With the motor that is.

As for the rest of it. The first mod you need to make to any of these trucks is gauges. Fuel pressure, Boost and Exhaust Gas Temps.

From there you need to fill in your signature so that we know the details of your truck. What part of the country are you from also, in case we have members or shops that we know of that may help if needed.

 

I can appreciate what your telling me, it just seems like every time I start it something else goes wrong. I am going to purchase gauges once I have the $$$$. But at the rate of repairs it is bleeding me dry. Hence the frustration. If I could get my mpgs up
I could begin to change my tune. But @ 3.70 a gallon its making me lose sleep and patience. But I thank you Bob and agree it seems I have only read the bad, no body posts the good.

 

keep it. every truck is going to have problems and most of what has happened to you has happened to many of us. Sensors and guages fail thats a given i have even seen trucks straight off the dealer lot lose guages. Also since you bought the truck used im assuming it was pretty much a given that the lift pump and ip would need replacing.

as far as the 53 block i have no personal experiance with it but from what i hear they are not as big of a problem as everybody and the diesel mags out there lead you to believe.

Also do you have a stick or auto. secondly where is your driving mostly at? I can tell you from experiance a dually with 3.55 in town will kill fuel mileage my 2wd usually drops to about 14-15 in town and on long highway runs i get up to 18+

 

As to fuel mileage, pull you Iat sensor located behind the map sensor on the driver side of the block above the fuel filter housing. Sometimes that sensor can get dirty as hell as hell and hurt fuel mileage. 12-13 on a 3500 really aint to bad, the ive seen guys get like 18 but thats about the make on that size. But anyway, check the IAT sensor, while your back there pull the map sensor and look for charing. 2nd Generation Dodge Cummins - Intake Air Temperature Sensor (IAT)

 

Yeah I already replaced the IAT sensor. I'm going to do the map sensor tonight. I have 2 buddies with the same truck and they get around 20 mpgs. Ugggg.

 

there are a lot of factors that go in to figuring the fuel mileage. like bubba said fill out your sig this will help everbody help you.

 

yup you aint the only one i bought mine as soon as i got it home the clutch went out the oil pressure gauge never worked the lift pump went out and took out the ip with it then found out my front axle was bent replaced that along with numerious other problems ive replaced steering gearbox power steer pump and steering shaft now the power steering pump is going out again as for mileage 16-17 on the highway with 3.55 gears 14-15 in town at best also my front main is going out but i still love that pickup to death it just depends on whether you love it or not

 

Oh I like the truck but if this is the best mpg I'm going to get, then I'm going to buy a Ford v10. If it's going to suck fuel I'd rather buy the cheap gas. This is just not what I expected. But it's going back to the mechanic on Thursday. I hope he can figure something out. Or I'm trading it in. I heard gas stations are going to have a bucket of KY at the pump so it doesn't hurt so bad.

 

I replaced all, just like you, and i had the 53 block too, keep it dude. My buddies bought a VP from somewhere and got horrible fuel mileage, he still is pissed that he gets 12 mpg at any driving conditions, pushn, pulln, a/c, everything. VP and LP work as they should, just crappy mpg.