Hope somebody can help. 2002 Dakota 3.9l V6, 5 spd. manual, 4X4. Was idling down steep hill in 4WD. Heard metalic knock from engine, puff of smoke, died. After much diagnosis, problem is failed intake manifold gasket with evidence of backfiring. Two ways this could have played out. The engine could have backfired, blowing out the intake manifold gasket. Other scenario is gasket could have sucked in allowing mixture to lean that then caused a backfire. Truck is under warranty but I have a bad feeling the dealership is going to try and worm out of fixing it. Has anyone heard of this before and/know what causes it? Thanks, you may save some service manager a very bad day!!!

 

From what I understand intake leaks on the 3.9 are somewhat common. My 97( 3.9 5 spd) has a small leak that causes it to run rough and/or backfire and die after I coast to a stop in cold weather (40 deg or lower). I have heard from other owners with the same problems as mine but I have never heard of a situation as bad as yours. I do not, however, know the cause. It still a mystery to me. As for haggling the service manager if its under warranty 5yr 36000 mile drivetrain means 5yr 36k. So I say tell'em tough sh*t its under warranty so fix it. Good luck man. Hope this helped a little

 

Hi acrivers and all.....Thanks for the reply. I got a hold of Dodge TSB 09-05-00 that details the problem. When I showed them a copy of their own service bulletin on the thing they made good and repaired it. A few thoughts. The problem was actually a leaking intake plenum manifold gasket. The gasket that seals the thin piece of tin under the manifold. It is evidenced by either the engine sucking its own oil, or as in my case , by a spark knock under load that changing plugs, gas etc won't get rid of. Eventually this leaned out the mixture enough to cause a backfire that then took out the intake manifold gaskets as well. Mine had been leaking about a year due to the spark knock that has now disappeared. The permanent fix is to replace the plenum tin with a thick aluminum piece from hugesengines.com. Thanks again for all the help. Showing the dealer that Dodge recognized this as a common problem sure helped. Cheers.

 

I really need some help here. I have a 1995 Dodge Dakota 3.9 liter engine. I have been having some problems with a coolant leak. I'm not sure where it is comming from, but it seems to be comming from around the upper part of the waterpump area or the thermastat area. I have changed the thermastat, the waterpump, the waterpump by-pass hose, and the heater hose that is located next to the thermastat. I put some water in the system, and found no leaks earlier today, I attempted to start the truck, and guess what the leak is back.And to add insut to injury the truck won't start now. I've been in the heat and sunshine for 2 days. Is there anyone that can help???