3.9L Ticking and Mediocre Power
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3.9L Ticking and Mediocre Power
Just gonna post this as an informational for people to check if they have similar issues as me.
I have a 1998 Dodge Dakota Sport with a 3.9L V6, only owned it a couple months (and rebuilt the trans already, that was a rollercoaster).
Anyway, ever since I bought it, there's been a ticking almost like a lifter or dist rattle. The truck also seemed to lack power I would expect it to have, but I attributed it to being a V6.
I could also never get the truck to really spin tires unless the pavement was wet (only tried a few times, not going to be a happy go lucky destroyer of tires). I thought the reason for not being able to spin was it being a V6 with 3.55 gears, and the larger optional tires. All this aside, the truck is still very nice, previous owner said they put another engine in it, changed this and that, and from my inspections, they've been honest about it.
Here's where some other investigations come in... Besides the ticking, I noticed I'd get random misfire codes on cylinders 1, 3, and 5 randomly, but ONLY if I ran 70+mph, if I keep it around 65 (my normal) the codes never show... However, I never ACTUALLY had a misfire. Hours of googling resulted in only a couple of forum posts that have both symptoms of ticking and misfire codes: Canister Purge Solenoid.
Popped the hood to look for it, couldn't hurt to do some tests. It's located on the drivers side of the intake mounted on the firewall, a green check cap is a dead giveaway. I wanted to see if unplugging it would stop the ticking or something... Lo and Behold... right on the top it said... "Bottom" ...seriously. When the previous owner put the new engine in, they put the solenoid in upside down. Pulled the vacuum lines, flipped it over, hooked it back up... The tick is gone! Now the truck purrs like a kitten, as a test during break I decided to see if it changed anything else. I just might have done a few donuts in the back lot of where I work, dry asphalt no less.
Not only did it fix the ticking, I got an increase in power as well! I'm assuming with the vacuum lines being reversed on the valve, it simulated a leak and that sapped some power. The vacuum also drawing backwards was slapping the valve causing the ticking on duty cycle. I haven't done a test yet, but I'm hopeful that it fixes my random misfire codes as well, now the vacuum and fuel system should be acting right. A side note it also leveled out the idle a bit (I plan to remove and clean the TB/IAC this weekend)
Maybe doing this will help fuel economy a little too, since now it can actually use the returned fuel and adjust accordingly. Just tossing this experience out for those who either have these symptoms or just want to check into it. Ensure the valve is installed correctly, plug on top, green check on vacuum hose is the upper vacuum line. Even if it's not mounted upside down, it going bad, or stuck open can cause a vacuum leak condition, be sure to check all the lines going to and from as well.
I have a 1998 Dodge Dakota Sport with a 3.9L V6, only owned it a couple months (and rebuilt the trans already, that was a rollercoaster).
Anyway, ever since I bought it, there's been a ticking almost like a lifter or dist rattle. The truck also seemed to lack power I would expect it to have, but I attributed it to being a V6.
I could also never get the truck to really spin tires unless the pavement was wet (only tried a few times, not going to be a happy go lucky destroyer of tires). I thought the reason for not being able to spin was it being a V6 with 3.55 gears, and the larger optional tires. All this aside, the truck is still very nice, previous owner said they put another engine in it, changed this and that, and from my inspections, they've been honest about it.
Here's where some other investigations come in... Besides the ticking, I noticed I'd get random misfire codes on cylinders 1, 3, and 5 randomly, but ONLY if I ran 70+mph, if I keep it around 65 (my normal) the codes never show... However, I never ACTUALLY had a misfire. Hours of googling resulted in only a couple of forum posts that have both symptoms of ticking and misfire codes: Canister Purge Solenoid.
Popped the hood to look for it, couldn't hurt to do some tests. It's located on the drivers side of the intake mounted on the firewall, a green check cap is a dead giveaway. I wanted to see if unplugging it would stop the ticking or something... Lo and Behold... right on the top it said... "Bottom" ...seriously. When the previous owner put the new engine in, they put the solenoid in upside down. Pulled the vacuum lines, flipped it over, hooked it back up... The tick is gone! Now the truck purrs like a kitten, as a test during break I decided to see if it changed anything else. I just might have done a few donuts in the back lot of where I work, dry asphalt no less.
Not only did it fix the ticking, I got an increase in power as well! I'm assuming with the vacuum lines being reversed on the valve, it simulated a leak and that sapped some power. The vacuum also drawing backwards was slapping the valve causing the ticking on duty cycle. I haven't done a test yet, but I'm hopeful that it fixes my random misfire codes as well, now the vacuum and fuel system should be acting right. A side note it also leveled out the idle a bit (I plan to remove and clean the TB/IAC this weekend)
Maybe doing this will help fuel economy a little too, since now it can actually use the returned fuel and adjust accordingly. Just tossing this experience out for those who either have these symptoms or just want to check into it. Ensure the valve is installed correctly, plug on top, green check on vacuum hose is the upper vacuum line. Even if it's not mounted upside down, it going bad, or stuck open can cause a vacuum leak condition, be sure to check all the lines going to and from as well.