I hope someone in this forum can help with this problem.
I have a 98 Durango 5.2 SLT. When the engine reaches operating temp it will loose power and miss/ backfire. When I first crank it over it will start with no issues. I can rev the engine with no problems as well. When the temp gauge reaches 200 the truck will loose power, backfire & cut in & out. It is not drive able when acting this way. I have replaced the crank shaft sensor, tps sensor, cleaned the throttle body with carb cleaner, installed new oil sensor, plugs, wires & ignition coil I replaced the cap & button yesterday 09/02/18 "I looked at the old cap and button & the electrodes were white inside of the cap." The truck started fine & would idle with no issues. I let the truck get to operating temp & I drove it around the block a few times. On my 3rd trip the truck started bogging down & loosing power. I put it in 1st gear while driving but the problem seemed to get worse. I shifted back into drive but the vehicle is still not functioning properly. Has anyone had this problem with their Durango or 5.2. This is the only vehicle we have at the moment & I really need to get it running properly. Please advise - Thanks

 

Unplug the front O2 sensor, and see if it runs any better.

 

Thank you for the reply.
I disconnected the front O2 sensor. I noticed the CAT was cut off & replaced by piping. I let the truck warm up & drove it around the block 3 to 4 times. There were no issues with the power or the idle while driving or in park. I let the truck set for a few min & tried to go around the block again. The truck lost all power & was jerking / hesitating when backing up or in drive. The lower O2 sensor was still connected. Should I disconnected that sensor as well? I did notice something that was not happening before. When in park or drive the idle become erratic. The idle would go up & down getting lower each time then would die. Do you think the IAC is the issue? I read online the TPS can adjust the idle by moving it up or down/ until you reach the correct voltage. Should I try that since I replaced the TPS? I really appreciate your feedback & suggestions for resolution.

 

Sounds more like something is getting heat-soaked, and partially failing. Are you getting any codes?

 

I don't have a scanner I have to go to the auto pats store for the scan. I will have the port scanned when it cools off & post the codes. The check engine light came on after I disconnected the o2.
To give you a break down on how this came about.
A few months back I had the truck scanned & the only codes that it gave was the cam shat sensor. I replaced the TPS first. The truck was still dying & would not start. I replaced the cam shaft sensor & it was running great for a few weeks. One day I noticed there was a bad oil leak. I was thinking it was the main seal going bad. After researching the issue I found the oil sending unit was not tightened down & had backed out. So I replaced the oil sending unit & the oil issue was resolved. After I replaced that part the truck started with my current issue. I replaced the ignition coil, cap & button, wires & plugs but nothing has correct the issue.

 

There are two connectors back there, one for the cam sensor, one for the crank sensor. Check and make sure they are both plugged in good, and the connections are clean. You may have simply disturbed a wire somewhere, so the PCM isn't getting proper signal from one or the other. It would fit with your symptoms......

 

Thanks for the input. I will let it cool off & check the connections. The oil leak was very severe from the oil sending unit. I hope it didn't corrode or damage all of the connectors.

 

I checked the wires from underneath the truck but I didn't see an issues. I started the truck & it sounds like it has a heavy cam. I tried to back out but there was too much hesitation. It preforms the same in drive. I checked the plug wires as well & they are seated properly. I don't know what to do next. The truck has had a full tune up but it is still not running properly. Do you have any other ideas? I noticed the rpm gauge was idling up & down when I had the truck in drive & park. It sounded sick & would not back up at all. After a minute or so the truck would die. I tried to start it after it died & it started with no hesitation but it still has the same issues.

 

Sounds like you are missing on a couple cylinders. Could be a bad sensor, or, it may be the PCM itself. It gets hot, and some solder joints separate, and then it runs like dog doo doo.

Get a plastic bag full of ice, run the engine till it starts acting up, put the ice on the PCM. See if anything changes. (might take a minute or two.....) Don't just pour water on the PCM though, that tends to really annoy them.

What brand crank sensor did you get? Dodges are notorious for not getting along well with the aftermarket sensors. (and the cheaper the sensor, the less likely your dodge is going to like it.)

 

A can of compressed air, held upside down will do the trick.