1999 Dodge Ram 1500 5.9L idles rough. What could be the problem?

25 comments

1. ejalba on December 14, 2009 at 1:07 am

   Sorry about how this posted, read my comments backwards and it makes sense.

2. DubbleDJay on December 15, 2009 at 5:01 pm

   Hey, thanks for all the info. When it warms back up I will go through all the details of this and see if any of it applies. The idle is right. I think 800 rpm is common on most all engines. Don’t know about diesel though. New cat in it since 3 years ago. Think the O2 sensors are new with it however I need to have the computer checked.

3. ejalba on December 15, 2009 at 6:00 pm

   You might be surprised how dirty the TB will be. It’ll prob take about 30-45 mins to clean it out, but it’ll help smooth out the idle

4. 2003edge600 on December 28, 2009 at 3:59 pm

   oh good lord thats a terrible noise at 3:45
   Im thinkin youve probably gots a bad censor somewhere.
   The cat maybe by the sounds of that garbage. That whistling noise beats me though

5. 2003edge600 on December 28, 2009 at 4:00 pm

   PS: I suppose the whistling could be the intake

6. mikekimdeindylan on December 28, 2009 at 8:01 pm

   hey man that sucks and im telling ya it is defintly ur egr valves i got a 2000 dodge ram 1500 ex cab and i had the same problem u ada see my vids

7. OsirisEGHatch on January 4, 2010 at 2:54 am

   Intake mani gaskets is my guess.

8. dclower06 on January 8, 2010 at 11:16 pm

   i would have to say egr valve also, i had a 95 and that was the problem

9. ccdevilbadassdeadman on January 11, 2010 at 7:26 pm

   u might wanna check ur thermostat. my camaro is doing the same thing and its cause of a bad thermostat

10. darkmp40 on January 13, 2010 at 1:49 am

    egr

11. discjuggler12345 on January 17, 2010 at 5:39 am

    I have a 3.9 Dodge and i had a problem similar to that. My Idle Air control valve was stuck.
    On the 5.2 and 5.9 models, there is an EGR valve system behind the distributor and it is vacuum sealed. Check that out. Like i said, its a guess because my 3.9 doesn’t have the same ERG configuration as yours does.
    Anyways, those are the two things that I would check, your EGR Valve system, and the IAC Valve in your throttle body.
    Hope this Helps!

12. daytonite122 on January 26, 2010 at 1:04 am

    Its probably both your Idle control valve and MAF sensor. My mom has a dodge van and they are known for always having problems with that. Its a common dodge problem. Their idle system sucks.

13. Begbucks on January 31, 2010 at 6:24 pm

    on my 92.5.9 the o2 sensor runs on the same circut as the MAP & coolent temp switch (I had a similar problem, disconected the collent temp switch, (idle was a bit higher) drove for a 3 weeks, reconected & problem solved, my guess it was the PCM (or Powertrain Control Module), having a bad code, those themselves usually need replacing at 200K on the pre 95 around 150k on the newer models, the wistling is likely the air intake tube cracked
    btw the o2 sensor should be replaced every 82,500 miles

14. Begbucks on January 31, 2010 at 6:28 pm

    the air intake tubes crack (like on some ford 4.6, town cars, when some numbskull tries to replaces the alternator by prying the air intake system out of the way for clearance, a little super sticky double sided coax tape is an easy fix

15. smartpartsionlover on February 14, 2010 at 10:01 pm

    check your temp sensor my uncles did the same thing and thats what it was

16. army1ty on March 10, 2010 at 4:43 pm

    try replacing the idle air control valve mine is the exact same truck it did the same thing when i first got it now it runs as smooth as a champ maybe it has a camshaft did u think about that?

17. DubbleDJay on March 10, 2010 at 6:24 pm

    This is likely the problem along with the MAF sensor. Thanks for the info. I’ll look into this more.

18. mikefoley69 on March 30, 2010 at 8:43 pm

    I have a 94 dodge ram 1500 which ran fine until I took foot off the gas pedal. It died and wouldn’t restart. The dealer replaced two fuel pumps. It was the crankshaft sensor. sounds like a sensor.

19. spudbud2005 on April 14, 2010 at 3:13 pm

    i dont know if you have fixed it yet because you have so many comments lol but i have a 98 ram 1500 that had the same issue took me a year to find out that my o2 sensor on my cat (the last one) was bad. it didnt throw any codes or anything and i just happen to be at autozone one day and got one….replaced it…and bam! runs great ever since….but mine was hissing and sounded like it was camming just like the video

20. DubbleDJay on April 15, 2010 at 9:24 am

    @spudbud2005 The cat was stolen from the truck about 4 years ago and when I had it replaced I don’t think the new sensor was wired right. Which means you are right on. I really do appreciate your post the most. It’s makes sense. Thank you!!!

21. BigZ636 on April 15, 2010 at 4:31 pm

    i have a 1970 mercury meteor and i will have the same problem but mostly the problem with mine is the automatic choke will stick and so it will run on the choke too long and when the truck is warm enough the choke is supposed to kick off but it doesn’t so it runs rough. I don’t know if thats the problem with yours but you should look into it.

22. jstnumber73 on April 19, 2010 at 7:01 am

    @StillOnWin95 Its a timing chain. There is nothing wrong with the timing as it only does this idling. Sounds like the egr.

23. 9DodgeFan on April 24, 2010 at 10:14 am

    @DubbleDJay
    Agreed. My ‘94 5.2L did the exact same thing when an O2 sensor went bad. Should be a cheap, easy fix if that’s the problem.

24. tylan13chuck on May 1, 2010 at 10:00 pm

    one time our car was doing something like that but it would idle real rough if you left it and died and it was a mapping sensor

25. dirtracer3031 on May 12, 2010 at 7:16 pm

    o2 senser

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