Shake at idle

[Mikes91]

Since I've owned the truck, I've noticed a shake while the truck is idling.

New lines, caps, and injectors when the turbo went on in 2003 didn't solve the problem.

Any idea why the truck would do this? The Ford mechanic who looked it over a few weeks ago didn't feel it was a significant issue... but I wish I knew what it was.

I've not done a compression check... don't have the time and tools to do it myself... don't want to pay Ford to do it.

The shake is especially visible if I open a door while the truck is running and parked... door moves up/down about half an inch.

Idling up just a bit seems to help just a little bit. idle is about 700-750 right now... so a bit higher than spec.

ON EDIT: This shake does not occur regularly during the idle process... not necessarily equal time intervals between each shake.


Thanks,
Mike

 

[Swany]

A little bit of shaking with 198k on the clock? I don't know if I'd really worry about that...especially since it's been doing that since you've had it (I'm assuming since 91?)

 

[towcat]

how old is the IP? Or how many miles are you aware of on it?

 

[Mikes91]

Originally posted by towcat
how old is the IP? Or how many miles are you aware of on it?

Swany, Towcat...

I've had the truck since 167,000 miles... January of '03. I had the IP done last year... no change in shake.

 

[argve]

Mike,

For what it's worth in all the engines that I put in The Enterprise they all were smooth as silk for about 30k miles then would pick up the shake your describing. I would not worry about it. I spent lots of time, effort and money trying to get it back out and never could find the root cause of it. Finally just wrote it off as the nature of the beast.

 

[Pacific]

It must have something to-do with the automatic because my truck doesn't shake that bad only when its cold. Hows the motor mounts are they tight is the rubber still in good shape also hows the transmission mount.

Diesel engines shake the Thermodyne in the MR Mack I work with viberates at idle so much you can't see out the mirrors. Its about the same with the two L-9000 Fords with 400 Big Cam power.

Try bumping up the idle 50 rpm see if it smooths out I don't know how high you can go with a automatic and not have problems shifting in and out of gears.

 

[Mikes91]

Originally posted by Pacific
It must have something to-do with the automatic because my truck doesn't shake that bad only when its cold. Hows the motor mounts are they tight is the rubber still in good shape also hows the transmission mount.

Diesel engines shake the Thermodyne in the MR Mack I work with viberates at idle so much you can't see out the mirrors. Its about the same with the two L-9000 Fords with 400 Big Cam power.

Try bumping up the idle 50 rpm see if it smooths out I don't know how high you can go with a automatic and not have problems shifting in and out of gears.

Not sure on that question... although I prefer higher idle because it makes the truck respond better off the line and idle through parking lots faster.

Will probably get her turned up, timed, checked out, and the idle bumped up in a couple months after tax comes back.


Mike

 

[Mikes91]

Originally posted by Pacific
It must have something to-do with the automatic because my truck doesn't shake that bad only when its cold. Hows the motor mounts are they tight is the rubber still in good shape also hows the transmission mount.

Diesel engines shake the Thermodyne in the MR Mack I work with viberates at idle so much you can't see out the mirrors. Its about the same with the two L-9000 Fords with 400 Big Cam power.

Try bumping up the idle 50 rpm see if it smooths out I don't know how high you can go with a automatic and not have problems shifting in and out of gears.

Sounds like this may be normal... just a little aggravating because I'm not absolutely certain about that...

The truck is an auto. Motor mounts are new, and have been adjusted once because the first shop didn't put them in tightly enough.... so I suspect the motor mounts aren't the problem.

Carrier bearing and u-joints all replaced shortly after truck was purchased. No change.

Dunno about the trans mount, although the tranmission was replaced 5000 miles ago so there should be no problems there (I assume the shop would have said something if anything needed attention).


Mike

 

[LUCKY_LARUE60]

I would get the compression and the injectors checked, my 93 shook untill I replaced the injectors and now you can set a coffee cup on the air cleaner lid and it will just set there, smooth.................. Jim

 

[geonc]

Just for S+G, take all the belts off, or if a serpentine belt-remove it completly, then run at idle.

I had a vibration that drove me to drink {more } and turns out the fan had been damaged from a serp belt failure.

Doing this test will aid in eliminating any belt driven accessories

You may also try cracking the inj lines and seeing if the vibration is isolated to 1 inj/cyl.


Just my 2 pennies................

 

[yARIC008]

Mike, i believe we've kinda talked about this before. Kinda like Travis said though, my engine was silk until about 30k miles went by, now it has a shake. Uneven just like yours. When i rev it up a little it kinda goes away but you can feel it's unequalness alot more. It's like.. SHAKeeeshakeeSHAKKEEEshakkee.

I know it isn't the tranny. My old engine shook like this, i replaced the engine, did nothing to the tranny, shake went away then came back when engine got about 30k miles. And just recently replaced the transmission and it didn't effect the shake at all.

I have noticed one thing that does effect it. Heat. When the engine is really cold you can't even feel the shake. If i tow something heavy and the engine heats up a bit, the shake is much more prominent. I was attributing it to an injector, but i'm not sure yet. I'm wondering if it has something to do with how the rings on the pistons wear. My heads are the same heads from the old engine, so that's not causing the shake. Only thing it can be is injectors or piston rings. I don't think belts would cause this, i had all my old belts and accessories when i switched engines, and had no shake for a while. I replaced belts after shake started and it had no effect.

Perhaps a good compression test will yield some answers. Pretty tuff to do on my engine though. If i get ahold of a compression tester though i will try to figure it out.

I wonder if a tweaked out harmonic dampener would fix things. Or i wonder if just after the engine runs a while it somehow gets out of whack and the balancing that whoever did on it isn't accurate anymore. Ah, who knows....

 

[towcat]

Milke-
before you get too stressed out over this. DON'T. If it comes and goes, there isn't a problem with the compression. It sounds like there is a injector that is getting funky (again). Just because they are new, that doesn't mean that they will pop and flow the same like the one next to them. Dualie and I pop tested over 75 injectors and got some very interesting results. Even "new" ones don't pop the same. I used to have a injector pump shop that flow matched new injectors for me if I brought him lunch. Okay, I can do that. Don't worry about it in the meantime if it comes and goes. Pull the oil cap, look to see how you smoke stream is coming out and that will tell you if you got a hole that is weak at the rings. Hell, I drove my F350 CC back from TX with a valve intermittently hanging up. These trucks are very abuse tolerant, but don't try a stunt like mime. They are not built with the precision of a Benz diesel but they will run a a very wide "fudge" factor.

 

[argve]

Mike,

I just remembered something... about two years ago when I was all hot and bothered with my ******* in a bunch over my miss/shake I replaced the delivery valve in the injection pump which did make it go away but it did come back. You might try that but I'll tell ya it's not for the faint of heart as you have to pull the nose cone, vane pump, and fuel regulator off the injection pump to get at it.

 

[Mikes91]

Thanks, guys... This is a good thread on this topic--we've discussed before elsewhere, but I didn't get the resolution there that I got here.

Like others have noted... my truck's shake is heat dependent... never gets out of hand, just noticeable. Would be interested in knowing the cause... suppose only IH or Ford may know that answer with certainty.

Sounds like this is ops normal. Most of the potential culprits have been checked/replaced already, so will just deal with it until time to replace the injectors or until they have to be pulled for other reasons...

Thanks,
Mike

 

[towcat]

mike-
wanna have some fun and screw up the parking lot a little too? when you are warmed up and shaking a little, get a wrench and crack open the injector line at each injector, one at a time, and see if there is a rpm drop-off when you do so. if there is, that isn't the bad injector. If there is no rpm drop, then that is your suspect injector.