Ive had my dakota for five years... needless to say it has been very good to me. It had 100xxx mi or so when i bought it, and it's about to turn 200 in the next month or so. I want to throw it a party this summer.

2 problems i have seen over and over again as ive been reading through these threads also plague my baby. The oil pressure dropping, and the stalling at idol and having to feather the throttle to keep it going.

From what i gather, the plenum pan gasket is the cause of the oil pressure drops. I burn oil like saddam hussein... and when i look down in the tb the port toward the driver side, the walls are caked with black oily goo, the port toward the passenger side is relatively clean except for the puddle of oil sitting in the bottom (which seems to burn off during the next warm up... if i dont let that happen before i drive it the truck drives like it has p.m.s.).

What i think i should do: take the intake off and replace any seal, gasket, etc that i can find. To get to it the only things new to me and my truck would be taking the fuel injectors out (would it be worth it to replace the injectors while im in there regardless of condition?) And i think i have to take the valve covers off (those gaskets need replaced anyway).

Which leads me to my next problem... there have been a couple of times since ive owned my truck that it ran with low levels of oil... a couple of times its sat for months... and for the last 2 years it had been running 15-20° higher than it does since i replaced the water pump and discovered that the fins on the pump had completely corroded away.

Considering these factors, im willing to bet it would be a good thing for my truck if i put new cylinder heads on. Not something i really have experience in haha. But the plan is, put new ones on... check to see if mine are rebuildible (is that a word?), and if they are... new hardware all around, put em back in. Im not looking for the cheapest way obviously... im looking for the way that's gonna keep my truck on the road the longest :-)

Id also like to replace my exhaust manifold... no death sentence from it yet, but it's not pretty. Only code im throwing is p0138 (high voltage downstream/rich)... but i think that has more to do with the intake issue.

Any and all opinions and advice welcome!

 

I havent done the belly pan but it's supposedly not hard at all. Injectors need not be removed, just unhook the supply line from the rail.

Get an exhaust gas tester for coolant, to see if the heads need any kind of help. Don't touch what doesn't need fixing, you will get in a deep hole quickly with the 3.9. Hint: they dont make a good aftermarket head like they do for the 318/360. The commodity of a V6 just isn't there.

Use the good blue felpro gaskets for the valve covers and intake gaskets, not sure what belly pan options are. Remove the sensors from the throttle body, and give it a good bath/soak while you do the bellypan gasket.

Not sure what to say on oil pres dropping, you can remove the sensor and clean it, or replace it.

If you want to be endeavorace, drop the oil pan and check if there's a magnet in it, and inspect the oil pump/pickup assy.

 

Thank you for the advice! Especially on the aftermarket heads. Might i be able to get new ones from the dealership? I've looked on the mopar website... and found they only go back 10 years :-/.

Ill have to do some homework on the coolant gas test. I know when i changed my oil there were 2 perfectly flowing parallel white lines in the oil as it was draining.

3 years ago i dropped the oil pan to replace the gasket (im going to have to do that again soon... it appears as though i boched it) cleaned everything up real nice. The OP problem went away for about a week, then started dropping right after i would get off the eway. Within 3 weeks it was back to the usual every time i stop the pressure drops. Changed the sending unit the next time i did a good oil change (after a drive from northern ohio to the everglades)... same thing... problem goes away, then eases back into the daily routine. So i start to notice, no matter what else i did... the good oil change made the problem stop temporarily... this is when i realized i was burning oil, not just leaking it. Since i "fixed" the leak... ive noticed i burn oil faster when normal pressure is maintained... but the truck runs fantastic as long as i let it warm up and burn away the puddle in the intake. Im just concerned about the toll burning the oil faster will have on my engine. But i think the attention to the intake and tb will disappear the op drop problem... leaving me the damage of it going on for 100xxx mi to deal with.

 

i dont think dealers carry the heads, either. Kind of an SOL problem.

the bellypan should take care of the oil consumption

remember, these motors only take 1 gallon of oil. Way i figure it, 1 quart in the filter, 1/2 quart atop each head, and 2 quarts in the pan. Doesn't take much to get a low level, i figured that one out.

Have you ran a leakdown or compression test? I'm afraid to on mine, in fear of finding a bad hole or 2.

 

Hmm... what do you think about rebuilding the existing heads? (Is that what's called a "valve job"?) Would it help with the tick i got from running low on oil so much?

That is a very good point. Im starting to think the only reason the oil pressure drops is because the oil pan gets completely drained. That would make some sense out of the problem (on mine and many others ive heard of over the years) starting primarily after sustained high rpm driving... because the pump pumps the oil in faster than it gets back to the pan. Im sure the jacked up VC gaskets dont help the situation.

Never heard of a leakdown test, and i haven't doen a compression test but i think i know what that one is haha... is that where you fit an air compressor hose to the spark plug port and watch the radiator for fizz?

 

the tick you hear is from the lifters. It's fairly common among several motors. I know the *.7 motors had it bad at first. It's kind of accepted for a traditional cam engine.

If there's poor drainback from the heads, they'll hold alot fo oil and I'm sure the pump could get starved if it got bad enough.

Leakdown requires specific instrumentation, and tells you how good/bad the piston ring seal is. Compression test uses a 500PSI pressure-set gauge, and records the maximum input pressure as the engine is spun over.

 

its all do to the "plenum plate" which its called its bolted to the bottom of our intakes. i would get the upgraded kit from someone on here.old style is alum. on steel diff. cool down temp. resone for oil in intake ...........L.O.P is bc ur loosing pressure in ur crankcase due to leak thus flakey reading tb off clean or better yet replace (200.xxx) miles ...ur iac.... map sensor....who knows how oil will ruin thing good luck