Last post on Oct 26, 2010 at 5:26 PM
You are in the Dodge Dakota-2010 and older
What is this discussion about?
Dodge Dakota, Transmission, Truck
#4 of 23 Re: More on 1990 vibration [tjfitz]
Sep 11, 2007 (3:36 pm)
This problem could be caused by a number of things. The easiest and most logical things first, like plug wires, rotor, and distributor cap, regardless how they look to the eye.
#5 of 23 Re: More on 1990 vibration [dustyk]
Sep 13, 2007 (8:00 am)
Thanks for the replies, Dusty. I'll go out and pull off the distributor cap and the rotor and have a look. Unfortunately a cold front hit North Dakota today and I may have to wait a day (no garage).
#6 of 23 Re: More on 1990 vibration [tjfitz]
Sep 13, 2007 (6:01 pm)
A short story. My son had a '91 Dakota, 3.9 motor and 5-speed manual. At about 70,000 he started have performance issues in the form of a heavy miss at speed. We could also hear a back fire through the throttle body occasionally. He was convinced that it was a burnt valve.
After doing a complete tune-up (plugs, wires, cap & rotor) it seemed to run fine for some time, then started to do the same thing. There were three occasions when he couldn't even get the thing started.
Well, he was about to tear the engine apart, convinced that the timing chain was bad (he was listening to all of his Chevy friends), or a bad camshaft or bad valves. I was not convinced, however. Having his truck one day I went and got and installed new Mopar plug wires, cap, and rotor and that Dakota ran for another four years and 75,000 miles before needing another full tune-up.
In that vintage especially the Power Train Computers were highly susceptible to disruption from random electrical impulses brought about by misfiring caused by poor ignition components.
By the way, that '91 Dak is still on the road and has more than 400,000 miles on it (No tear down!).
#7 of 23 Re: More on 1990 vibration [dustyk]
Sep 17, 2007 (8:23 pm)
Dusty, sorry I didn't come back to the forum before tonight. That last note is very encouraging and I think I'll go forth and do likewise with the cap, rotor and wires!
I took the cap and rotor and wires off and the rotor metal looked pretty rough. The contacts inside the distributor cap were what I'd call delaminated, with flaking metal. The wires seemed OK, but who knows?
I put it all back together, and the engine started, but I can't road test it because I'm going to have to replace one of the metal brake lines after a leak developed at the "combination differential and metering valve" (name in my Haynes manual). I thought tightening the flare nut might help, but instead the leak got worse and I am hoping it is just the tubing flare inside the nut that failed and not the very pricey valve.
#8 of 23 Still vibrating
Sep 29, 2007 (7:56 pm)
I installed new Mopar distributor cap, rotor and spark plugs wires.
Then after some struggles I got the new long metal brake line installed. In the process I had to lower the fuel tank to get at some of the old line's hangers and in moving the filler hose I broke the plastic of the filler line housing and had to scout around in a junk yard today for another one. That was installed and all well. The bleeding of the brake lines for air went well, too, although I now have two alarms on the dashboard illuminated continuously: "ABS brakes" and "P Brake". I may have to continue bleeding the system because the brake fluid was dirty.
I took the pickup out for a spin anyway and found the vibration under load is still there at about 35 mph in drive. In second it also vibrates at 35 mph although at a higher rpm. Shifting into neutral at that speed eliminates the vibration. Revving to high rpm in neutral doesn't cause the vibration.
During the test drive, the rpm gauge began sticking and only gentle hammering on the dash would make it move. (The pickup seems to have a death wish!)
The idle is very rough and the engine dies at idle unless I disconnect the vacuum line to the EGR valve.
Using the ignition switch, I switched the ignition on and off three times and then left it on the fourth time and got these codes: 12, 12, 13, 14, 14. The information I can find seems to say those codes relate to the MAP or maniford absolute pressure sensor.
#9 of 23 Warning lights sorted
Oct 01, 2007 (3:01 pm)
I neglected to bleed the "hydraulic valve" on the drivers side above the rear axle. When that got done, the warning lights went out. Brakes are now good. This pickup has rear wheel antilock only.
#10 of 23 Vibration problem solved
Oct 02, 2007 (8:43 pm)
Yesterday I backed the pickup down the driveway, and as I shifted from park into reverse, there was a distinct "clank".
Somewhere in the recesses of memory I recalled that clanking and vibration can be symptoms of a bad universal joint on the driveshaft. This morning I got up early, raised the rear tires off the pavement, supporting the rear axle with two stands and went to work trying to moving the u-joints. I have never done this before, but from what I read, any "give" at all might mean a bad joint, and the rear joint had give. I eventually got the rear joint disconnected from the differential and lowered it then pulled the front of the driveshaft out from the transmission, forgetting that transmission oil would be gushing forth, which it did, all over the driveway before I was able to get one of my wife's cooking pots under the stream.
As far as I could see, there were no needle bearings left in the rear joint, so I took shaft and all to a local parts dealer/machine shop and they removed the joints and installed new ones. I put the shaft back into the pickup and added what I think was enough new transmission fluid then took the pickup out on the road.
There was no more clank on shifting, and absolutely no more vibration even going as fast as 60 mph. The pickup now runs like a dream.
When I asked my daughter how long the pickup had been vibrating before, she said about a year, and her sister had the same problem before she handed the pickup over to her! (That was the first I'd heard of it.)
I think the brake line mentioned in an earlier posting in this thread probably failed by vibration fatigue. Also, my daughter drove the pickup from Idaho to North Dakota when she returned home about two weeks ago and about 50 miles from home stopped to rest and the pickup wouldn't re-start. She had to get roadside assistance at about 11 pm from a tow-truck and the driver found that the starter was hanging onto the engine by one loose bolt. I'd say the bolts had probably vibrated loose.
"For want of a nail... ."
#11 of 23 Re: Vibration problem solved [tjfitz]
Apr 29, 2008 (2:00 pm)
My 1989 Chevy Blazer has the exact same problem and I believe the u-joint may be the solution. how much did it cost you to have it repaired?
#12 of 23 Re: Vibration problem solved [jslack05]
Apr 29, 2008 (3:19 pm)
jslack05, I think the two u-joints (front at the transmission output and rear at the differential) cost about $15 each. I brought the drive shaft with its u-joints to the local machine shop that is attached to the parts dealer. I think it cost $45 to pull the old u-joints and press the new ones on. So that probably makes a total of about $75. Usually I keep all the receipts for any work on my pickup, but I can't find the receipts for this work. Sorry I can't give you better info.
#13 of 23 Re: Vibration problem solved [tjfitz]
Apr 29, 2008 (4:53 pm)
ok that sound reasonable, i'm sure it will cost a bit more for me cause i'll need to take it to a mechanic since i don't have the tools to do it myself but thank you for the valuable information.