96 Ram 1500 - 318 - Oil light

Ok guys, I have been reading your posts for quite some time now and I have used alot of the good advice here. I am at my end with an oil problem.
I have a '96 Ram 1500 Quad Cab 318 5.2L. Last month I had the plenum
gasket replaced. After that, my check engine light came on and the code came up as the EVAP code. They checked all the hoses on the intake and cleared the code. Then just two weeks ago I had the thermostat changed out because I was having erratic heat temperatures coming out the vents at idle.
Now, I have my oil light coming on. This only happens if the truck runs for a good 2hrs in city driving. Above 40 at cold and after warming up. After the 2hrs, I come to any stop sign or a complete stop and the truck is at idle. The light will come on and the needle will drop way low (enough for the lite to come on) and start to flicker. I checked the oil level and it is at the "safe" level. I know it blows blue smoke but it has been doing it for years. Oil pressure gauge jumps back to normal while driving.
I am at a loss. I had one place tell me it might be the pistons/rings or valves that need replaced. I am not sure if it might be a bad job when they replaced the plenum gasket. Just at a loss and would like to know if anyone else had this problem or if anyone knows what the problem is.
Hate to get rid of this truck, since it has been a great truck and with almost 150,000 miles on it.
Any help would be appreciated.
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On Sun, 09 Mar 2008 08:42:25 -0400, Ann wrote:

How often has the oil been changed? regularly? as in every 3,000 miles? put a manual gauge on it and run it for long enough to get it acting up, if the manual gauge shows a problem then drop the pan and look. i suspect you will find sludge particles floating around in the oil pan, these get picked up in the oil pump's pickup screen little by little. then you find a dropping or erratic oil pressure. most common is the dropping oil pressure. If you find sludge your best course of action is to replace the engine assy. the next best would be to clean the pan, replace the oil pump and pickup tube then hope you can last a while before enough of the sludge up top gets dislodged to start causing you problems again.
When i was working on cars i replaced more than a few engines for this very thing.
another guess would be that you have a leaking oil pressure sending unit. I've seen them leak into the plastic housing and after its warmed up good give all kids of erratic/wrong readings before again this can be proven with a visual inspection and mechanical oil pressure gauge.
--
Chris

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What kind of extended warranty do you have on a 12 year old truck?
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I bought an extended warranty from a company for a couple grand that covers about 75% of the engine and powertrain. But it only pays out if there is a part that actually breaks down. Will cover gaskets, etc.. if some tear down is required to get to a part. It will cover pistons and rings! so that is why I am thinking of having them pay for that along with whatever else it takes to get to the pistons. Just hoping that there is nothing else discovered while tearing down.
Engine runs smooth, no knocks, pings, etc.. other than this #@$^$# oil pressure problem and blue smoke. I can smell the smoke when I have to put it in reverse when backing into the driveway or if at idle I give it gas.
If I have to do a rebuild. I will buy a new truck and sell this one or keep it parked in the driveway until I have money for a rebuild.

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The subject line was changed so it shows up as a new topic.
--
Ken



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