Why do chrysler engines have a whine?

[Nick R]

Curiousity finally got the better of me. Why does it seem that all, or nearly all, chrysler engines have a whine noise at WOT or higher RPM. It seems characteristic to most chrysler engines. Anyone knowledgable on this?

Here are some videos that showcase the whine noise.

4.0L Inline 6- Mostly audible above 4krpm
http://www.youtube.com/watch?v=bZjrkXa7u04&feature=channel_page

4.0 V6- Clearly audible through most of the RPM range.
http://www.youtube.com/watch?v=gIIkbk6sEqs

2.7L V60 Audible above 3krpm
http://www.youtube.com/watch?v=a7lpfE02b5g&feature=channel

2.4L Inline 4- Audible above 3krpm
http://www.youtube.com/watch?v=2gZ7WeJcEFA&feature=channel_page

3.5L V6- Audible above 3.5krpm
http://www.youtube.com/watch?v=zQSGIVbo-oo&feature=channel_page

4.7L V8- Audible above 4.5krpm
http://www.youtube.com/watch?v=J6eoKJfqlFM&feature=related

 

[Colt45ws]

Many things can cause a whine. Certain serpentine belts do it. Sometimes bearings going bad on the belt drive and make noise. Air intake design can also cause it. You will often hear it from cars with 'cold air' intakes. Sometimes it can come from the speakers if the electrical noise from the alternator isnt filtered. It shows up as a whine that gets higher as you go up in RPM. Watch a video on YT of a cop chase from the dashcams. Almost every car sounds like it has a supercharger on it, but it is just electrical noise from the alternator the recorder picked up.

 

[tom slick]

To go with their rusty swiss cheese bodies!*

*according to StevieC's latest rants

 

[mechjames]

power steering pump i believe. when I got my stratus, it had a mild whine from the power steering pump. it did eventually need to be changed, but the reman I installed is much quieter, but still a little whine to it.

 

[hounddog]

The 4.0 INLINE 6 is not really a Chrysler engine.Believe it got its design/start from AMC way back when.Got to be something EXTERNAL from the engine causing the noise.

 

[paul246]

As mentioned already, power steering pumps are a frequent source of whine. Apparantly, some pump designs require a very specific fluid. If the fluid isn't within spec, air bubbles can be produced and lead to a whine while under load. Quite common on Ford products.

 

[Colt45ws]

Yup. Or people ignore them like they typically ignore everything except the gas gauge and it goes low, causing aeration and noise.

 

[asamek]

"Why does it seem that all, or nearly all, chrysler engines have a whine noise at WOT or higher RPM."

I believe it's because they are all female.

However, I could be mistaken...

 

[440Magnum]

I've owned quite a few of the engines on that list- a 4.0 inline (as someone else pointed out, its an AMC design that Chrysler beefed up quite a bit over the years), a 3.5, and a 2.4, and a 4.7. Plus I've had all the others in rental cars at one time or another too. What you have represented there are 5 very different engine families, so really the only things in common are external:

1) AMC inline (2.5 and 4.0)
2) 60-degree belt-timed SOHC v6 (3.5, 4.0, and 3.2)
3) POS 2.7 (sorry to those who own them, but that's the only Chrysler engine I've ever actively disliked)
4) 3.7/4.7 90-degree SOHC
5) 2.0/2.4 SOHC and DOHC inline 4 with balance shafts

In the case of the 3.5 and 4.0 v6 (the two are identical apart from a difference in bore) the ribbed timing belt makes a slightly audible whine at certain RPM ranges. Same for the 2.4, plus it has its chain-driven geared-together balance shafts that *might* contribute some sound but I never hear them. All the others are chain timed so any timing chain whine will be more muffled, although the 2.7s chain system is notoriously loud because of its multiple snubbers and two secondary chains.

I can't hear ANY whine in that Grand Cherokee video (I don't know whether to be impressed at the guts or shocked at the stupidity of taking a GC to >100 mph, but that's one healthy modified 4.0!), and the only "whine" I can hear on my own 4.0 is from the serpentine belt and PS pump. The 4.0 inline was built in such huge numbers and for so long that it comes in quite a few slightly different configurations that make different sounds. The serpentine belt is differently routed on a Cherokee vs. a Wrangler vs. a Grand Cherokee, and the older 4.0s didn't have the main bearing cap girdle and a few other goodies that Chrysler added over the years to stiffen the assembly, so they sound subtly different too.

FWIW, my wife's old 3.5 had a fairly noisy PS pump too- it was a GM/Saginaw pump. Older (70s and earlier) Mopars used Federal PS pumps that were very quiet, and later Mopars seem to use ZF pumps, and they're also a little quieter than the Saginaws. The Saginaws with a divorced reservoir like the 3.5-equipped vehicles have are even louder because the integral reservoir on the others acts as a sound-deadener with all that fluid right around the pump itself. Never had a lick of trouble from a Saginaw, but they have a very characteristic sound- you can hear it on many GM cars too.


Originally Posted By: rudolphna
Curiousity finally got the better of me. Why does it seem that all, or nearly all, chrysler engines have a whine noise at WOT or higher RPM. It seems characteristic to most chrysler engines. Anyone knowledgable on this?

Here are some videos that showcase the whine noise.

4.0L Inline 6- Mostly audible above 4krpm
http://www.youtube.com/watch?v=bZjrkXa7u04&feature=channel_page

4.0 V6- Clearly audible through most of the RPM range.
http://www.youtube.com/watch?v=gIIkbk6sEqs

2.7L V60 Audible above 3krpm
http://www.youtube.com/watch?v=a7lpfE02b5g&feature=channel

2.4L Inline 4- Audible above 3krpm
http://www.youtube.com/watch?v=2gZ7WeJcEFA&feature=channel_page

3.5L V6- Audible above 3.5krpm
http://www.youtube.com/watch?v=zQSGIVbo-oo&feature=channel_page

4.7L V8- Audible above 4.5krpm
http://www.youtube.com/watch?v=J6eoKJfqlFM&feature=related

 

[StevieC]

Alternators...

If it were a Ford it would be a Power Steering Pump

If it were a GM, well... I will leave that unsaid.

 

[440Magnum]

Originally Posted By: StevieC
Alternators...

If it were a Ford it would be a Power Steering Pump

If it were a GM, well... I will leave that unsaid.

Yeah, funny how a Nippondenso alternator will be utterly silent on a magically perfect T*yota, but will whine like a banshee when it knows its installed on a Chrysler.

 

[StevieC]

Not all Chrysler vehicles use Nip. alternators... Also they are probably built to different specs, knowing Chrysler... Remember the Mitsu engines that used oil when installed by Chrysler but not in other Mitsu cars?

Also... All of the Chryslers we have serviced where people complained it was the Alternator or Transmission whining.

 

[440Magnum]

Originally Posted By: StevieC
Not all Chrysler vehicles use Nip. alternators... Also they are probably built to different specs, knowing Chrysler...


Not as far as I can tell. All the internals are the same, the only thing specified differently is the number of pulley grooves and the mounting tab locations. I like Nippo alternators a lot more than the Bosch and Mitsubishis that Mopar seems to have preferred in the post-Daimler era. In fact a couple of my vintage Mopars now have 130A Nippondenso alternators from 90s era Dodge trucks. All it takes is a twin-groove pulley and a mounting bracket extender made from a piece of steel sheet stock.

Originally Posted By: StevieC

Remember the Mitsu engines that used oil when installed by Chrysler but not in other Mitsu cars?


I've rarely seen a mitsu engine that didn't eventually spew blue smoke, no matter what it was in. I was behind a Montero that was killin' skeeters just last week.

Originally Posted By: StevieC

Also... All of the Chryslers we have serviced where people complained it was the Alternator or Transmission whining.


That's actually a good point- the newer Chrysler transmissions tend to run full hydraulic pressure all the time and let the variable duty-cycle solenoids control everything, rather than mechanically regulating pressure. That does make the pumps generate a little more noise than older trannies with hydraulically regulated line pressure.

 

[VNTS]

Originally Posted By: StevieC
Not all Chrysler vehicles use Nip. alternators... Also they are probably built to different specs, knowing Chrysler... Remember the Mitsu engines that used oil when installed by Chrysler but not in other Mitsu cars?

Also... All of the Chryslers we have serviced where people complained it was the Alternator or Transmission whining.


all I can say is Valve Guide Update, didnt matter where the 3.0 was installed.

 

[PT1]

Originally Posted By: tom slick
To go with their rusty swiss cheese bodies!*

*according to StevieC's latest rants

ROFLMAO.....

 

[440Magnum]

Originally Posted By: VNTS

all I can say is Valve Guide Update, didnt matter where the 3.0 was installed.


And the last "valve guide update" I recall went like this: "Put a circlips around the part of the guide that protrudes out of the head so that when (not if...) it gets loose in the head at least it won't flutter up and down along with the valve."

Sheesh, what a piece of junk the top end of that engine was. Gotta say the lower end was fairly bulletproof (although part of the oil burning was attributable to too-small ring lands).

 

[StevieC]

Originally Posted By: 440Magnum
Originally Posted By: StevieC
Not all Chrysler vehicles use Nip. alternators... Also they are probably built to different specs, knowing Chrysler...


Not as far as I can tell. All the internals are the same, the only thing specified differently is the number of pulley grooves and the mounting tab locations. I like Nippo alternators a lot more than the Bosch and Mitsubishis that Mopar seems to have preferred in the post-Daimler era. In fact a couple of my vintage Mopars now have 130A Nippondenso alternators from 90s era Dodge trucks. All it takes is a twin-groove pulley and a mounting bracket extender made from a piece of steel sheet stock.

Originally Posted By: StevieC

Remember the Mitsu engines that used oil when installed by Chrysler but not in other Mitsu cars?


I've rarely seen a mitsu engine that didn't eventually spew blue smoke, no matter what it was in. I was behind a Montero that was killin' skeeters just last week.

Originally Posted By: StevieC

Also... All of the Chryslers we have serviced where people complained it was the Alternator or Transmission whining.


That's actually a good point- the newer Chrysler transmissions tend to run full hydraulic pressure all the time and let the variable duty-cycle solenoids control everything, rather than mechanically regulating pressure. That does make the pumps generate a little more noise than older trannies with hydraulically regulated line pressure.


Must be a US thing... Up here there are a combination of Bosch and Nip. alternators on the Chrysler line...

As for the oil burners... Never saw a Mitsu burning oil unless it was heavy on the miles... Although the Caravan's with the 3.0's seem to smoke quite early in their lives...

I would still take a 3.0 litre over most other engines anyday. So it smokes a bit, you can't kill 'em!

Originally Posted By: PT1
Originally Posted By: tom slick
To go with their rusty swiss cheese bodies!*

*according to StevieC's latest rants

ROFLMAO.....

Laugh all you want, I know the truth. I just pray you are never taxed by your idiocy...

 

[steve20]

not to mention the characteristic sound of a 1960's-early 1980's sound of the Chrysler starter. You could hear a Chrysler turn over hundred of feet away. Can't think of letters to descrbe the sound, but you'd know it if you heard it again


Steve

 

[Kruse]

Originally Posted By: steve20
not to mention the characteristic sound of a 1960's-early 1980's sound of the Chrysler starter. You could hear a Chrysler turn over hundred of feet away. Can't think of letters to descrbe the sound, but you'd know it if you heard it again
Steve


The whine is from a gear reduction starter. GM and Ford did not use them and you could really hear the difference.
When I was going to automotive tech school, we had an instructor (obviously anti-Chrysler) who said that it was a Mopar product saying "I ain't gonna start!"

 

[440Magnum]

Originally Posted By: steve20
not to mention the characteristic sound of a 1960's-early 1980's sound of the Chrysler starter. You could hear a Chrysler turn over hundred of feet away. Can't think of letters to descrbe the sound, but you'd know it if you heard it again


Steve


I still hear it all the time... in my garage!

As someone else said, its the reduction gear starter that Chrysler used, whereas Ford and Delco were still all direct-drive. The funny thing is that today the vast majority of starters are reduction gear types because they can be made so much smaller and lighter. The very popular Nippondenso offset-gear reduction starter is nearly a miniature of the old Chrysler. Others (Mitsubishi, for one) use planetary reduction gears. They sound different because the new permanent or semi-permanent magnet motors spin *really* fast. But if you take the sound of a Toyota with a Nippondenso starter and slow it down about 30%, it sounds eerily like an old Valiant.

Speaking of recordings of starters... the sound of a Chrysler starter was probably *THE* most often-used canned starter sound effect in 60s-80s movies and TV. It cracks me up to watch an old episode of 'The Rockford Files' and hear his Firebird or one of the bad guys' Fords make a Chrysler starter sound...