hi I am new to the forum so thanks in advance for the patience .I am a building maint engineer and pretty mech inclined . but I am having trouble with a 1997 dodge ram van 2500 5.2 it has 133000 miles it idles rough but above idle rpm it smooths out . under a load at idle it shakes but when it warms up it is less noticeable I changed plugs wires and cap and rotor same thing tried spraying carbcleaner thru throttlebody while running still the same maybe worse. there is no fuel smell from exhaust plugs removed were relativly clean a little white.no smoke and no check engine light . tell me where I should start please thanks .

 

Welcome to the site. I will move this thread to the Dodge Ram van section,
FF

 

133K? Has you IAC ever been cleaned?
https://dodgeforum.com/forum/dodge-r...n-the-iac.html

 

ever have the injectors tested? ever put an oscilliscope on the ignition and injector circuits to see if you have clean/equal waveforms? Ever do a compression or leakdown test?

about 18 years ago, I had a 318 come thru with a rough idle that was caused by a gaulled rocker arm shaft due to a lack of lubrication. One exhaust valve would hang just a little at idle but at higher rpm the problem disappeared. the only way I figured out the problem is with an ignition scope that showed that one cylinder was misfiring. compression and leak down was ok because with the engine off and turning by hand the valve closed fully. I eliminated plug/wire it took quite a bit of time to pinpoint but after about 20hrs of struggling and pulling the cylinder head, I found the problem.

Also, an intake manifold leak could also cause these symptoms along with a sticking/leaking EGR valve

I guess my point is, you need to use a rational and pragmatic problem solving approach into solving this issue. You need to know how the systems of an engine works and what sub systems can affect the whole system

 

Magnum 5.2 and 5.9, except maybe CA emissions, do not have EGR systems.

 

thanks very much as I said I am new.

 

hi and thanks for the sugestion I will check it tomorrow . I appreciate the info .

 

hi and thanks for the help. but no I havent tried these things yet . I have only been working on it a day . but will try system by system.

 

is that ALL? my dakota 5.2 Magnum has EGR not CA spec. my 1996 3500 5.9 has EGR not CA spec.

So maybe his van doesn't have EGR, but in general an EGR valve will cause this EXACT problem.. hot rough idle... ok at cold startup and fine during hot cruise.

So since you want to correct me, then where are YOUR possible solutions to his problem? Unless you're offering advice of value, then don't be nit-picking someone that is!

 

The vehicle in question is a 1997 Ram Van 2500 with a 5.2L and no EGR valve and not a 3500 5.9 or a Dakota 5.2 with an EGR valve. That being said, I submit that any mention of an EGR valve does nothing to solve the problem, however it's mention is nothing less than detrimental in solving the problem.