2004 8.1 loss of power and poping noise

[hd1084]

I have a 2004 Pace Arrow, 37C with an 8.1. I recently installed new plugs and good wires from Summit at about 22000 mile.
After its warmed up it begins to lose power and makes a poping noise as if it was back firing when under a load. It seems to get worse as it gets hotter. Tech road with me with a scanner hooked up and said there were no codes but # 4 was cutting out now and then and then clearing itself.
Anyone have any ideas??

[DriVer]

Quote:

Originally Posted by hd1084 After its warmed up it begins to lose power and makes a popping noise as if it was back firing when under a load. It seems to get worse as it gets hotter. Tech road with me with a scanner hooked up and said there were no codes but # 4 was cutting out now and then and then clearing itself.

My question would be, what did the tech suggest is wrong with your engine since he DX'ed the situation with a Tech II scanner?

You should be beyond the point of wondering what's wrong.

I have a pop but it's more related to my Mass Air Flow Sensor which I am waiting to resolve .. shortly.

[hd1084]

Quote:

Originally Posted by DriVer My question would be, what did the tech suggest is wrong with your engine since he DX'ed the situation with a Tech II scanner? You should be beyond the point of wondering what's wrong. I have a pop but it's more related to my Mass Air Flow Sensor which I am waiting to resolve .. shortly.

He said he has to think and research it tonight but he mentioned the possibility of a warped plastic intake manifold but he said it was strange that it was only # 4 and not all across the board. He also stated a possible coil pack or even going back to OEM wires ???

[DriVer]

Quote:

Originally Posted by hd1084 He also stated a possible coil pack or even going back to OEM wires ???

Did you replace your own wires? It's quite possible that you could have a bad wire or it's not snapped on all the way. Have not heard of an intermittent coil pack, although it may be possible. Let us know what the final diagnosis is and if the problem was fixed.

[dieselclacker]

hd1048,

Was the engine running OK before you changed the plugs and wires?

Dieselclacker

[Full-Timers]

Quote:

Originally Posted by DriVer Did you replace your own wires? It's quite possible that you could have a bad wire or it's not snapped on all the way. Have not heard of an intermittent coil pack, although it may be possible. Let us know what the final diagnosis is and if the problem was fixed.

These wires do have a tendency to back off the plug if it wasn’t snapped on completely. I would recheck all wires, especially #4.

[DriVer]

So that's 3 re-check your wires!

Git-er-done!

[hd1084]

Quote:

Originally Posted by DriVer So that's 3 re-check your wires! Git-er-done!

Just wanted to report back on what we did. My guy replaced #4 coil pak and also replaced the plugs and wires back to OEM and we took a 400 mile trip to Erie Pa. and it ran great. Not sure what the real problem was but if I had to guess it was the coil pak. Just MHO. Anyway thanks for all the feedback and I'm just glad it's running great again. Thanks, Mark.

[Airtool]

On My 8.1 lost the came sensor at around 60K without looking at the records.Would start and run fine one time and then the next time it would run rough. Turn it off and the next time it would run smooth.
The other issue was the crank sensor failed. Dead stop at 65mph. No power steering and little braking power. Not cool. Cooled down and ran smooth again.
The crank sensors are on recall from NTSB if your Vin number falls right, But how much difference can there be in the 8.1 regarding sensors.

Dick.

[MegaRoadie]

Quote:

Originally Posted by Airtool On My 8.1 lost the came sensor at around 60K without looking at the records.Would start and run fine one time and then the next time it would run rough. Turn it off and the next time it would run smooth. The other issue was the crank sensor failed. Dead stop at 65mph. No power steering and little braking power. Not cool. Cooled down and ran smooth again. The crank sensors are on recall from NTSB if your Vin number falls right, But how much difference can there be in the 8.1 regarding sensors. Dick.

Sooooooo... how about that NTSB Recall link for us 8.1 drivers there Dave???

[iRV4FUN]

Quote:

Originally Posted by MegaRoadie Sooooooo... how about that NTSB Recall link for us 8.1 drivers there Dave???

A Vin # Range would help. Could something like this cause a bigger problem? This may deserve a new Thread!

[DriVer]

Quote:

Originally Posted by Airtool The crank sensors are on recall from NTSB if your Vin number falls right, But how much difference can there be in the 8.1 regarding sensors..

I don't see an open NTSB campaign or WCC TSB in my resources regarding crank sensors for 8.1L engines used by Workhorse.

[Topflite51]

This might be the recall he is referring to, however I believe it was for 8.1's that were installed in some pick ups that were manufactured in 2001.

NHTSA ID: 07V521000 Issued: No. of vehicles: 00011974
Engine and Engine cooling on certain pickup trucks equiped with the 8.1L V8 Engine, the crankshaft position can operate intermittently or fail completely. If the sensor operates intermittently, the SES light may illuminate and the Vehicle may run rough. The Engine may stall, and if so, may Re-start immediately or after a Cool down period. If the sensor becomes completely inoperative, the Engine will quit running and will not Re-start. Either of these failures can increase the risk of a crash. Dealers will replace the crankshaft position sensor free of charge. The recall is expected to begin during December 2007. Owners may contact Chevrolet at 1-800-630-2438 and GMC at 1-866-996-9463.

[DriVer]

Quote:

Originally Posted by Topflite51 This might be the recall he is referring to, however I believe it was for 8.1's that were installed in some pick ups that were manufactured in 2001.

Topflite51, Thanks for finding the extended version of the 07V521000 NHTSA Campaign. I have not seen this campaign on the resources that are available to me.