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whistle when car is REALLY cold

Discussion in '308/328' started by JoeZaff, Dec 14, 2008.

  1. JoeZaff

    JoeZaff F1 Veteran
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    Aug 5, 2007
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    Quick question,
    on really cold days (20-45 degrees) when I first start my car there is a whistling almost like a high pitched whooing sound from the engine bay. It is intermittent and goes away once the car begins to warm up (2 minutes). The car had a complete engine out service two years ago, with all new belts, seals, etc, and the bearings were inspected, but deemed to not need replacing (not my call--previous owner), which I am sure they would have done had they thought it was necessary considering it was a money no object servicing. Car has relatively new waterpump too. Is this just a common racket when these cars are really cold?

    Car is a '86 mondial 3.2 cab
     
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  3. snj5

    snj5 F1 World Champ

    Feb 22, 2003
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    Not uncomon; mine had it
    Air bypass valve.
     
  4. JoeZaff

    JoeZaff F1 Veteran
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    Aug 5, 2007
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    Was it constant? or was it intermittent? Mine almost sounds like a mechanical whistling and it starts and stops for first few minutes until going away altogether. Does this sound similar to your experience?
     
  5. desire308

    desire308 Formula 3

    Oct 19, 2007
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    #4 desire308, Dec 14, 2008
    Last edited: Dec 14, 2008
    It could be the oil cooler whining, or whooing as you say, when it's cold. Mine does.
     
  6. snj5

    snj5 F1 World Champ

    Feb 22, 2003
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    To be honest I don't remember; there was never a lot of exposure to really cold weather and the K-jet came off 5 years ago. It sounds right, though - the car has temp sensitive air bypass valves that change as the car warms up, and may or may not whistle due to induction air speed..
     
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  8. mike996

    mike996 F1 Veteran

    Jun 14, 2008
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    My 328 did exactly the same thing about a week ago in MD. It was 27 degrees out and it scared the heck out of me. I lifted the hood but before I could localize it, it went away. The car acted completely normal after that and after it was well warmed up I red-lined it in the first three gears up Highway 50 and back several times and it seemed happy with that...as it usually does.
     
  9. Brunello

    Brunello Formula Junior

    Sep 10, 2005
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    Had the same thing whining (loose fan belt) type sound when cold on my 328. Got it checked out and no one could find anything wrong with the car. There are threads on FChat that discusses the oil cooler system that produces a similar sound. I had all my external belts replaced and checked both the air con and water pump and no real answer. I can say that in the summer time when the weather is warm, I did not have the problem. Definitely a cold weather issue.
     
  10. Huskerbill

    Huskerbill F1 Rookie

    Sep 6, 2004
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    Another possibility is a micro crack in your air intake plastic hose (the one that is like 4-5" in diameter) on the right back (closer to the rear window) part of your engine bay. There is a metal bracket there with, I believe, a few rivets to hold it in place. Sometimes stress will crack this hose and you will get a hairline crack.

    When these pieces are cold, they contract and air will get sucked into the crack from the engine bay causing the whistle. As the engine warms, heat will expand the hose and "seal" the crack.

    Just another possibility if everything else seems to not be the answer.
     
  11. davehelms

    davehelms F1 Rookie

    Jan 3, 2004
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    Happens every year about this time and its OK. Its good to see the trend where owners are paying attention to new strange noises but this one is fine to have.
    Took a long time to answer the question back in the 80's when we first heard it. Some cars had it, some didnt so it had to be a critical issue! Nope, finally traced it to the oil cooler design.

    After removing and inspecting numerous oil coolers, both with and without the noise problem, we found the source. Some of the oil coolers had the oil cooling tubes that transfered the oil from one tank to the other protruding into the tank rather than sitting flush with the tank, a simple manufacturing variance one to the next. The coolers that whine when the oil is cold and thick are those that have more than 1/16" of tube protrution into the tank area. The noise is caused by the oil having to swirl around the protruding tubes, change direction 180 degrees and flow through the tube, those without the noise only require the oil to turn 90 degrees into the tubes.

    When the new coolers were still affordable we used to order 4 or 5 at a time, pick the ones that had flush tubes and return the others, a pratice that is now frowned upon these days.

    Changing to a thinner oil will cause the sound to go away a bit quicker but knowing it is a normal sound and that the oil is too thick to be driving the car yet...most now consider it a simple warning system and leave it as it is. No extra engine wear was ever found on the cars that were cronic whiners so I agree with leaving it alone and allowing some extra warmup time this time of year.

    Dave
     
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  13. desire308

    desire308 Formula 3

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    I must be learning quick Dave ;)
     
  14. davehelms

    davehelms F1 Rookie

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    You were spot on, I only added the explination so owners understood the "why" part
     
  15. JoeZaff

    JoeZaff F1 Veteran
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    Thanks so much for all of your help!!

    Feel much better now...
     
  16. snj5

    snj5 F1 World Champ

    Feb 22, 2003
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    Yes - in any event the problem is not serious.
    I will say that after I removed my aux air valve the car has never whistled or 'woo'ed' since.

    Best
    rt
     
  17. irondogmike

    irondogmike Formula 3

    Sep 8, 2006
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    Dave,I too thought it might be and was told it was the oil cooler,but my sound came after I changed oil,from kendall 20-50,to redline 10-30,never made the noise b4,my machanic told me its becuase the oil is thinner and rushing through the vents.............this noise I'm talking about sounds like a belt and a squell,but does go away when warmed up and many times shuting it off after wards is gone only returns when the car sit for over 8 hrs or more when cold????????
     
  18. JoeZaff

    JoeZaff F1 Veteran
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    Exactly!!!

    I will add that the sound happened again today when I started the car...and it was 60 degrees out! This sound just started happening in the last thousand miles (I assumed it was a winter noise because I just got the car...maybe not?)
     
  19. desire308

    desire308 Formula 3

    Oct 19, 2007
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    Mike, what "vents" is he talking about?
     
  20. desire308

    desire308 Formula 3

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    Dave...just messing with you [and I didn't know the history anyway]. I can't resist patting myself on the back ;)
     
  21. irondogmike

    irondogmike Formula 3

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    #18 irondogmike, Dec 15, 2008
    Last edited: Dec 15, 2008
    on the oil cooler there are like thin fins,and when the oil passes through the oil cooler its vibrating them and making a squell noise,I guess thats what I should've called them,not vents,and peter I might say your car is looking nice,to nice to give it to the buyer.........lol
     
  22. davehelms

    davehelms F1 Rookie

    Jan 3, 2004
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    Yup, sounds like that's it. Maybe you had a dilution issue with the Kendall.

    If you can trace the sound to the inlet tank of the oil cooler it is nothing to worry about and is SOP for this time of year. Using Brian's famous line "I cant hear it from 1500 miles away" (still makes me laugh when I think of it!) is probably prudent at this point in the discussion but at this time of year it is a very common occurrence that has scared the tar out of many an owner in the past.

    If you listen very closely with a good stethoscope, once the cooler stops making noise the pressure relief valve starts to sing for a minute or two and then everything quite's down to normal. Heck, its a more reliable indication of oil flow when cold than the marginally accurate oil pressure gauge we have!

    Dave
     
  23. mike996

    mike996 F1 Veteran

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    #20 mike996, Dec 16, 2008
    Last edited: Dec 16, 2008
    Good to know it's not an issue but I must admit that in 40 years of working on cars/building performance engines, I have never heard an oil cooler do such a thing. But, as I have frequently pointed out, I have never owned/worked on a Ferrari before and it almost (but not quite) makes my Norton Commando's weirdness seem "normal." :)
     
  24. irondogmike

    irondogmike Formula 3

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    #21 irondogmike, Jan 14, 2009
    Last edited: Jan 14, 2009
    today I had time to put the car up on jacks and took the wheels off to check on the belts and sure enough the a/c belt was so tight theres a shine on the pulley #19 on table refence #41,that can be adjusted,and thats what I did adjust it,and no more sound when its cold.......ta da!
     
  25. tatcat

    tatcat F1 Veteran
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    Sep 3, 2001
    8,517
    panama city beach FL
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    rick c
    started mine yesterday it had been sitting in the cold garage for the past few weeks and what a cacophony. between the alt belt snapping, the intermittent howl and a few new whines and stutters i had to keep chanting, "it's just cold..it's just cold." once it got warmed up it purred like a kitten.
     

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