Motor mount question

[NavyVet88]

Can bad or failing motor mounts cause a vibration that feels like engine misfire?

My 02 Ranger with 67k miles has new plugs, new coil pack, new plug wires etc. and there's no codes or CEL to indicate a misfire nor do rpms move at all while experiencing the vibration. This leads me to think it may be motor mounts and not an engine performance issue. The issue is most felt while stopped or at idle and is very noticeable.

How can I check the "health" of my current mounts? Just by looks they don't look bad but I know it is more complicated than that.

 

[eljefino]

Is this in drive or neutral?

A bad mount will bug you if it's a harmonic frequency, eg if you raise the idle 50 RPM and everything gets smooth and happy, your mount is bad.

We seem to notice this stuff in drive at idle.

 

[NavyVet88]

Originally Posted by eljefino
Is this in drive or neutral?

A bad mount will bug you if it's a harmonic frequency, eg if you raise the idle 50 RPM and everything gets smooth and happy, your mount is bad.

We seem to notice this stuff in drive at idle.


It is most notable in park and in drive at idle and seemingly disappears once under acceleration.

 

[01rangerxl]

That can be a mount, but it could also be 3.0 Ranger.

Vehicles I have been in with really bad mounts would shake pretty violently at idle and smooth out under a load. Worst I have seen was my aunt's old Aztec, it was almost undrivable because it felt like it was going to tear itself apart at idle. If it's not REALLY rough, it may be mounts, but it may not be. You can try prying against the engine when it's off to see if it feels loose.

Keep in mind aftermarket mounts can be pretty junky. Might be better off with worn but not done OE than cheap aftermarket.

 

[Jethro_Bob]

The Vulcan 3.0 is a 60 degree V6. Which means it's internally unbalanced. https://www.caranddriver.com/features/a15126436/the-physics-of-engine-cylinder-bank-angles-feature/

Quote
A 60-degree V-6 engine isn't quite as successful. The rotational and reciprocating forces can't be completely balanced because this type of V-6 is essentially two three-cylinder engines stuck together. Inline-three engines, because of their odd number of cylinders, are inherently imbalanced and will tend to rock from end to end.

 

[NavyVet88]

It is by no means violent or even horrendous. Just extremely annoying and I want to catch it before it gets worse.

 

[NavyVet88]

Originally Posted by Jethro_Bob
The Vulcan 3.0 is a 60 degree V6. Which means it's internally unbalanced. https://www.caranddriver.com/features/a15126436/the-physics-of-engine-cylinder-bank-angles-feature/

Quote
A 60-degree V-6 engine isn't quite as successful. The rotational and reciprocating forces can't be completely balanced because this type of V-6 is essentially two three-cylinder engines stuck together. Inline-three engines, because of their odd number of cylinders, are inherently imbalanced and will tend to rock from end to end.


I just had to go and buy this thing lol

 

[NavyVet88]

Wouldn't a bad mount let the fan hit the guard or something like similar?

 

[ARCOgraphite]

always had problems with ford spark and idle. what plugs?

That's A nice engine. Should be smooth.

If That has negative fire lost spark, it requires a special electrode on the negative fire side to run smooth
Also Are your gaps within five thou of spec?
I have a set of Denso TT but they are for my long gone ranger with the Mazda engine.

 

[NavyVet88]

Originally Posted by ARCOgraphite
always had problems with ford spark and idle. what plugs?

That's A nice engine. Should be smooth.

If That has negative fire lost spark, it requires a special electrode on the negative fire side to run smooth
Also Are your gaps within five thou of spec?
I have a set of Denso TT but they are for my long gone ranger with the Mazda engine.


Motorcraft OEM

 

[01rangerxl]

Originally Posted by NavyVet88
Wouldn't a bad mount let the fan hit the guard or something like similar?


That would be a REALLY bad mount, but it could happen.

Does the engine look like it's bouncing around a lot at idle?

Can you post a video of the engine at idle and one from inside the cab?

 

[NavyVet88]

Originally Posted by 01rangerxl
Originally Posted by NavyVet88
Wouldn't a bad mount let the fan hit the guard or something like similar?


That would be a REALLY bad mount, but it could happen.

Does the engine look like it's bouncing around a lot at idle?

Can you post a video of the engine at idle and one from inside the cab?


Mine does not hit the guard nor does it seem to lurch near it, but it does have a bounce to it under the hood and it is felt inside the cab. However, you cannot see anything from the inside of the cab.

 

[eljefino]

Originally Posted by NavyVet88

Mine does not hit the guard nor does it seem to lurch near it, but it does have a bounce to it under the hood and it is felt inside the cab. However, you cannot see anything from the inside of the cab.


So then it comes down to, is it bouncing because it's misfiring or is it running normal but on lousy mounts?

My inline cars have their motors sitting pretty solidly in their mounts. Not sloppy like FWD cars with their "dogbones" and what not.

I bet your mounts are good, and you still have a miss.

Try this, open your hood, and watch your motor from the drivers seat through that little 2" gap over the cowl. Brake stand it in drive, reverse, then let it sit in neutral. If the motor moves more than an inch your mounts are shot.

I think you still have a miss. Maybe something like an intake gasket leak making a cylinder run lean at idle but go down the road good. MAF issues, EGR stuck open, something like that.

 

[joegreen]

I have a 3.0 ranger with almost 190k. I'll have to pay attention to the idle. What is your resting rpm on the tacometer?

 

[NavyVet88]

Originally Posted by joegreen
I have a 3.0 ranger with almost 190k. I'll have to pay attention to the idle. What is your resting rpm on the tacometer?


At temp, it's about 7-800

 

[ARCOgraphite]

Originally Posted by NavyVet88
Originally Posted by ARCOgraphite
always had problems with ford spark and idle. what plugs?

That's A nice engine. Should be smooth.

If That has negative fire lost spark, it requires a special electrode on the negative fire side to run smooth
Also Are your gaps within five thou of spec?
I have a set of Denso TT but they are for my long gone ranger with the Mazda engine.


Motorcraft OEM

But is it waste spark? 3 dual ended coils?

Factory had 2 different plugs required, IIRC

replacement plugs may not have this and be one p/n which is incorrect.


Also Has the TB been cleaned and

all vacuum lines good?. Brake Booster grommet not sucking air?

Just know if you drive church lady like it will be carboned up and have a bad idle.

I find I have to run PEA once every 6 weeks with the crummy gasoline up here in N.H. - and I run Top Tier

 

[bdcardinal]

Originally Posted by ARCOgraphite
But is it waste spark? 3 dual ended coils?

Factory had 2 different plugs required, IIRC

replacement plugs may not have this and be one p/n which is incorrect.


From the factory each bank had a different part number plug, they were replaced by one part number per Ford.

 

[DuckRyder]

Originally Posted by bdcardinal
Originally Posted by ARCOgraphite
But is it waste spark? 3 dual ended coils?

Factory had 2 different plugs required, IIRC

replacement plugs may not have this and be one p/n which is incorrect.


From the factory each bank had a different part number plug, they were replaced by one part number per Ford.


Correct of course.

And the OP is describing a normal condition in a 3.0 Ranger IMO, it is a bit UH agricultural...

 

[Lubener]

Originally Posted by NavyVet88
Can bad or failing motor mounts cause a vibration that feels like engine misfire?

My 02 Ranger with 67k miles has new plugs, new coil pack, new plug wires etc. and there's no codes or CEL to indicate a misfire nor do rpms move at all while experiencing the vibration. This leads me to think it may be motor mounts and not an engine performance issue. The issue is most felt while stopped or at idle and is very noticeable.

How can I check the "health" of my current mounts? Just by looks they don't look bad but I know it is more complicated than that.

Have a helper put in gear with brake applied and goose the gas pedal, the engine will almost look like it will hop out of there if a mount is bad. Your mount would have to be broken to cause a vibration at idle. I would look at your fuel trims and if ok, do a compression check to see if all cylinders are within 10% of each other. If there is a large difference between the highest and lowest cylinder, you will never get a smooth idle and no CEL will be indicated .Makes no difference what your mileage is.