Did you have your throttle propped open when you did the compression check? (I really hope the answer here is 'no'.....)

If you did, don't bother throwing any more money at that motor till you have it at the very least re-ringed, and fix whatever other problems you find while it is disassembled.

 

OP, first post in this thread: "Last weekend fired up the 2001 Dodge 5.9 liter w/140,000 miles .... "

Me, earlier in this thread: "Speaking of gauges, I think your compression gauge is shot. Those readings sound awfully low, and since they're [relatively] consistent, I think your gauge is consistently wrong (unless your engine has about 250,000 miles on it). Also, make sure your throttle plate is wide open while you're cranking the engine during the test - the cylinders need plenty of air to compress".

Unless the oil hasn't been changed at least every 10,000 miles, I'm thinking that it's much more likely that the gauge is faulty (or the test was done wrong) than it is that the engine is really that worn. I've had a compression gauge go bad before; re-checked with a good gauge, then threw the old one away.

OP, could you please clarify how you performed the test; throttle plate open, or closed? Also, was the battery good and strong, or weak from trying to start an engine that didn't want to start?

Again, I highly recommend you re-test the compression with a different gauge and with a battery that has been fully charged and load-tested.

 

I think verifying with another compression gauge would indeed be an excellent idea.....

 

+2 (or is it +3). Compression gauges are not that expensive and another test before tearing an engine down would be a good investment. If you used a gauge from a parts store, I would certainly get another. Sometimes these have been used and abused by customers that don't know what they are doing, and don;t take care of equipment.

 

I had that code thrown at me when my TPS was on its way out. I also had a really rough idle and when it got really bad my truck would stall out. Maybe check that too before you send more money. There is a test for it in the Haynes manual.

Good Luck!

 

Stop looking for an O2 sensor problem, that's not a factor at cold startup.

Check the torque on the intake manifold bolts. 12ft/lbs.

If you notice any take a bit more torque, then torque all of them to 150 inch/lbs. (6 in/lbs. over stock ) and pull the alternator and a/c compressor and check the last 2.

Cap off the vacuum accessory tree at the intake manifold and see if the idle improves, if yes, cap off each tee in the tree one by one and see if you can locate the line causing the issue.

If it didn't improve, cap off the Evap port on the front of the TB, then the brake booster, then the PCV valve one at a time. if you find one that improves your idle, look for the leak in that system.

The last thing you may want to try is running a can of sea foam thru the intake. Occasionally, the intake valves get so much carbon build up that they soak up a bit of fuel on cold startup and actually lean out the cylinder a bit. Lean causes a misfire, as does carbon build up. It's a pretty rare occurrence, but it does happen.

Those compression numbers are too for that age of engine, unless you've been pouring your intake runners with sand while revving the engine

compression test should be done on a hot engine: remove all spark plugs, remove coil wire from top of coil, remove the fuel system relay under the hood in the PDC, and make sure the battery is fully charged up. Screw tester into a cylinder and then depress the gas pedal to the floor and crank the engine over until the reading won't go any higher. I like to run the gauge up to the window and wedge the tube under the wiper arm so I can see it while i'm cranking.

 

Only thing I would change in this procedure is, instead of unplugging the coil wire, unplug the coil electrical connector. (two wire) Disables coil completely, and won't jump out and bite you if it gets the chance.

 

So I was looking at the pile of parts I purchased to try and solve this problem and after trying most of them without fixing the problem I realized that I was just guessing in the dark. Time being my limiting factor right now I broke down and took it to the dealer this morning (trust me it killed me). That being said it was probably the best thing. They did a compression and leak down test on the cylinders and here's what they found.
Compression:
1- 125
2- 150
3- 175
4- 165
5- 175
6- 125
7- 180
8- 165

They performed a wet test (adding oil in cylinder 1&6) and retested compression. Both only went up only 5 psi and they said they should have gone up 50. They also watched the 2 cylinders bleed off in psi as it sat there. This explains the constant misfire on cylinder 1&6.

So the good news is that my compression gauge was bad. The bad news is that my heads potentially have cracks between the valves on cylinder 1&6. They recommended pulling them and getting them magna fluxed. My thought is by the time I pay for them to do that and a rental while the truck is down I might as well buy some aftermarket heads and take a day to swap them out myself.

Now I guess this thread turns into where can I get after market heads? I have seen a couple posts talking about summit. I guess I'll do some research. Can anyone point me to a good thread on head replacement?

Thanks,
Mike

 

You can get better-than-stock heads off of EBay, for under 300 bucks a pop. Or, you can go directly to the manufacturer, and get them there. (Odessa, or Clearwater cylinder head of Florida.) They are better castings than stock, and are a LOT less prone to cracking. You can even get them with upgraded valves/springs if you are so inclined.

 

Glad to see you now have an answer to your problem. I just did my heads last week you are looking at 4hrs to tear down and 10hrs to reassy.