Idle engine vibration

[svtrit]

2014 Chrysler Town and Country with the 3.6L and 128,000 miles.

It was pulsating while doing gentle rolling in line leaving a parking lot and when idling at stop lights, or in park. It eventually got to where I felt it at highway speeds, so I changed the engine mounts with Anchor mounts, which seem to be good mounts. Now I don’t feel it at higher RPM’s, but still at idle rolling in line in a parking lot and at idle. The headlights pulsate slightly at idle.

I pulled the 3 rear plugs, since the are easy to check. They look good and we’re at proper Gap. They have 50,000 miles.

New PVC valve was installed in December.

The alternator is putting out 14.5 Volts. The battery is two years old.

The oil filter had a bit of soft, spongy material in it the last oil change. I assumed carbon. I had been using Valvoline Max-Life 5w-30 until my latest change to VRP.

My wife has strongly suggested I stop putting money in this van and we live with it as is, but it’s one of those issues that drives me nuts. What have I missed?

 

[skyactiv]

Lots of things could be listed. Is the MAP or mass airflow sensor dirty?

 

[CharBaby]

Does it vibrate if you put the tranny in "N"?
Can you check the other 3 plugs and the coil packs?
Do you suspect or feel an engine misfire?
How's the power at full throttle?
I still(kind of) suspect engine mounts and maybe even the tranny mount.
But, it's hard to diagnose on a forum.

 

[Kira]

Try the product Chevron Techron Concentrate before a stint of local driving.
The dosage is 1 oz. per 1 gallon fuel.
The PEA in Techron is said to work at loosening deposits on injector nozzles upon shutdown.

Scan for "pending codes".

I do not know if spark coils "wear out" or just fail completely. If you know how to test them, do so.

 

[PontiacHO]

Check fuel pressure.

 

[Lubener]

Connect a scan tool and check for codes and what are your fuel trims . The fuel trims will tell you how efficiently your engine is performing. Then go from there. I favor diagnosing over sensor guessing.

From my experiences with aftermarket engine mounts, especially Anchor (junk ) is not good as the aftermarket ones have caused more vibrations. OEM is the only way to go when it comes to engine mounts.

 

[ka9mnx]

Vacuum leak?

 

[tnt_motorsports]

our 2014 had a little vibration to it before I changed the plugs. The OEM's had ~95K on them and looked used up. Did you put in a good plug? Champions are what is OEM for Chrysler. I used MGK and so far so good with 10k on them.

Just my $0.02

 

[svtrit]

Thanks for all the replies

The other 3 spark plugs can only be accessed by removing the intake. I should have changed the plugs when I did the oil cooler last August and had the intake off. I put the same Champions in that the van had from the factory. It may be spark plug time, which is where my gut is going.

I have wondered about a vacuum leak, but can’t find one.

My scanner showed no codes.

I have considered the Anchor mounts aren’t good. They were, however, more stiff than the worn out factory ones. I may try ordering one by one from MOPAR and see if something gets better. I did put the factory transmission mount back in because I did notice a vibration gain after doing that one. I did the engine mounts one weekend and the transmission mount the next, so I was able to feel the difference between all those mounts

I’ll hook up my fuel pressure gauge and check pressure, as well as try some Techron.

 

[tnt_motorsports]

If you think you have a vacuum leak you can spray starting fluid or carb cleaner around the different places and hoses to see if the RPM changes. I prefer carb cleaner to avoid any unexpected surprises.

I’d put my attention towards new plugs.

Just my $0.02

 

[Andyd95]

Anchor mounts are not good

 

[Opelman]

Is the engine rpm varying that much to be noticeable that the headlights are pulsating? Probably not relevant here but once I worked on an old Bronco with pulsing lights. A bad spark plug wire was jumping to a 12v wire running near it. The HV spike would pulse the lights when that cyl was fired. I can see where the coil on plug possibly but not probably could fail like that internally but you would see a misfire code.

 

[svtrit]

Is the engine rpm varying that much to be noticeable that the headlights are pulsating? Probably not relevant here but once I worked on an old Bronco with pulsing lights. A bad spark plug wire was jumping to a 12v wire running near it. The HV spike would pulse the lights when that cyl was fired. I can see where the coil on plug possibly but not probably could fail like that internally but you would see a misfire code.

The pulsating lights made me think there was a ground issue, or the alternator was failing. The lights stop pulsating when above 1000 RPM, like during a cold start. No codes definitely has be baffled for a coil or spark plug issue.

I am planning on getting rid of the van next year, so we may just live with it, if new sparkplugs don't work, or I don't find a vacuum leak. The power doors quit working and it's starting to rust in the dogleg. Modern Chryslers rarely make it past 150,000 anyway with out major issues, so it's time to dump it. My Camry has almost 150k miles on it and has NO electrical issues or visible rust, and it is 6 years older!

 

[svtrit]

Update

I’ve replaced the spark plugs, which brought no change. While doing the plugs, I searched for vacuum leaks and found none. I also checked all electrical connects. Nothing changed and no codes have popped up.

I was wondering about injector problems, so I’ve run 3 tanks of E85 through it on trips from Ames, IA to Omaha, NE and back, then to Aurora, IL and back. I filled up on E10 on the way back from Aurora.

The vibration has somewhat improved but is still there. I’m ruling out engine mounts because the vibration didn’t change with new mounts.

Do I have an injector issue? Any insight is appreciated. Another step I’m thinking is to pull the serpentine belt to see if it goes away, ruling out a mechanical issue such as alternator or water pump bearing drag.

Thanks.

 

[meep]

I don’t think the pulsating headlights are necessarily related … BUT… check for voltage loss between alternator case and the battery negative post itself, with headlights and AC and everything else turned up high. I had 2 gen IV T&Cs, and both pulsated. Both also had Huge voltage losses … I want to say one was 1.2V and the other 1.8 or 2.1. In those cases I used heavy wire and joined alt to other end of cyl head to chassis to battery clamp. In one, the pulsation quit and it shifted gears better than it ever had. In the other, they just pulsated brighter. Neither changed a lumpy idle.

If you have stumbles when accelerating, I’d be suspicious of coilpacks or wires.