Why does my F 355 stall out (almost) when the fan kicks on? | FerrariChat
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Why does my F 355 stall out (almost) when the fan kicks on?

Discussion in '348/355' started by ready321now, Mar 30, 2014.

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  1. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #1 ready321now, Mar 30, 2014
    Hi all,

    My car seems to idle fine until the fan kicks on at 190 degrees. All of a sudden, it starts chugging and sputtering.

    Saw this quote on F chat, thought it might be an aging fan motor, but others say that the fuse would always blow before it would stall.

    Quote" I recently had a 30amp left side radiator fan use blow recently. It did this once previously about 3 years ago. Knowing that this is not going to get better and according to others, is caused by aging fan motors drawing more start up current, and more current during operation. The drawing more current while the motors are running is a concern, since there is sporadic reports of melted 355 fuse panels on those circuits. Also, it can contribute to low idle and almost stalling of the engine when the fan motors cycle on, due to the current draw and extra load the alternator puts on the engine trying to keep up. (I have not experienced this) So if you have ever blown a radiator fan motor fuse, the cure is new fan motors."

    Where should I start? I am lost!

    Could it be the wrong type of battery? Going to check what type it is tomorrow.

    Anyone else have this problem? Just had a ton of work done, but it was doing this before I brought the car in.

    The other day, the chugging seemed to be much worse than before, and simply hitting the gas doesnt easily fix it. When the idle dips, it dips WAY DOWN to the point where the oil pressure light flickers and the engine wants to cut out.

    Thanks in advance, I am pretty torn up about this.
     
  2. Radiation

    Radiation Karting

    Mar 5, 2013
    74
    Alberta, Canada
    Full Name:
    Sean
    #2 Radiation, Mar 30, 2014
    Im not sure if this will help, but I had a very similar problem happen on one of my sports cars and it turned out to be the power wire coming off the alternator was making a poor connection. Actually it easily snapped off when I brushed my hand against it. The car ran relatively good but when electrical load was applied (fan, blower motor) it started to miss and run poorly until the load was no longer there.
     
  3. bobzdar

    bobzdar F1 Veteran

    Sep 22, 2008
    6,918
    Richmond
    Full Name:
    Pete
    #3 bobzdar, Mar 30, 2014
    How old are the fans? They're known to go bad and that's the exact failure mode, excessive current draw. If it's drawing enough current, it could bog the engine due to the voltage in the electrical system dropping and a high load on the alternator. I'd think if this were the case you'd be blowing fuses. However, I do know some cars have had the fan wiring modified to bypass the fuse box for this reason and if they did that without putting a breaker in-line, it could cause the issue you describe (and be a fire hazard).
     
  4. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #4 ready321now, Mar 30, 2014
    Thanks for the response.I assume the fans are 17 years old, as this is a 1997.
     
  5. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #5 ready321now, Mar 30, 2014
    Questions: Is the alternator accessible with the motor in the car?

    If my alternator is failing, would this match my symptoms? I just had the motor out for a belt service and do not have the cash to do it again.
     
  6. bobzdar

    bobzdar F1 Veteran

    Sep 22, 2008
    6,918
    Richmond
    Full Name:
    Pete
    #6 bobzdar, Mar 30, 2014
    Yes, easily accessible. Diffuser panels and engine underbody panel need to be removed and it's right there at the bottom front of the engine.
     
  7. fiorano10

    fiorano10 Karting

    Sep 29, 2004
    111
    los angeles
    #7 fiorano10, Mar 31, 2014
    first thing make sure your battery in not defective or holding only half charge, then I would check in to the fans.
     
  8. fiorano10

    fiorano10 Karting

    Sep 29, 2004
    111
    los angeles
    #8 fiorano10, Mar 31, 2014
    also forgot, make sure you have the ground wire that connected from the alternator to the frame is not missing.
     
  9. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #9 ready321now, Mar 31, 2014
     
  10. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,671
    San Carlos, CA
    Full Name:
    Mitchell Le
    #10 yelcab, Mar 31, 2014
    Let me suggest that you idle in your driveway and attach a DMV to the 12V line. See what it says when the fan is off and when the fan kicks on.
     
  11. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #11 ready321now, Mar 31, 2014
    Ok, sounds like I should put a volt-meter on a 12-volt line? Which line ? Do I connect this directly to my battery?

    Thanks for the feedback.
     
  12. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,671
    San Carlos, CA
    Full Name:
    Mitchell Le
    #12 yelcab, Mar 31, 2014
    There is a 3 post jumper port on the right hand side of the engine compartment. Remove the side cover over the shock and you will see the positive terminals (3) and one negative terminal. That is where you connect your V meter.
     
  13. RSO1091

    RSO1091 Formula 3

    Mar 31, 2012
    1,547
    Idyllwild, CA.
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    Henry S.
    #13 RSO1091, Mar 31, 2014
    The alternator is actually accessible without the need to remove the diffuser or lower panel. I've rebuilt mine in-place several times. While I never had the fan/idling issue, I ended up installing a digital voltmeter in my dash so I can monitor the battery and alternator output and perhaps head off pending issues. Good luck.
     
  14. DouglasNg

    DouglasNg Formula 3

    Jun 6, 2004
    1,041
    SG
    Full Name:
    Douglas
    #14 DouglasNg, Mar 31, 2014
    I also faced the same problem. idling speed dropped to 500rpm or lesser.

    1. Check your relays located in passenger footwell
    2. Physically check whether fan motors are touching radiator. The mounts can be loose over the years and cause the fan motor to come into contact with radiator.
    3. Apply voltage across fans to see if the motors operate at full power
     
  15. roadracer311

    roadracer311 Formula 3

    May 6, 2009
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    Paul
    #15 roadracer311, Apr 1, 2014
    Last edited by a moderator: Sep 7, 2017
  16. RSO1091

    RSO1091 Formula 3

    Mar 31, 2012
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    Idyllwild, CA.
    Full Name:
    Henry S.
    #16 RSO1091, Apr 2, 2014
    Last edited by a moderator: Sep 7, 2017
  17. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #17 ready321now, Apr 14, 2014
    Wow! nice mod.
    Question: Would measuring the voltage in the engine bay at the posts work? Someone said there might be degradation of the voltage signal if not measuring at the battery.
    Also, I notice TWO red cables and ONE black back there inder the bl;ack box with the red + on it. Which ones do I measure?
     
  18. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #18 ready321now, Apr 14, 2014
    Ok Thank you much....btw do I just pull up the foot rest to access these?
     
  19. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #19 ready321now, Apr 14, 2014
    Does anyone know where the Idle control valve thingy is? I saw it in the shop manual but could not locate it on the car despite a lot of looking.

    Also, what is that secondary air pump/ fan item down near thew rear lights? Mine looks like it has a dirty filter. Does that have anything to do at idle?

    Again, here are my symptoms:

    At start up, car idles a lot lower not, instead of a high idle, it seems a lot lower in these warmer temps. Does yours idle a lot lower in the summer vs winter?

    When the fan kicks on, the idle chugs and sputters with the oil pressure dropping a lot.
    SOMETIMES, it does not chug at all when the fan kicks on. This condition seems to come and go. What does that MEAN?!?!?!
     
  20. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #20 ready321now, Apr 14, 2014
    Just looked at the relays under the passenger side. I removed them and put them right back to see if there was a loose one....none. Did an ecu reset and have the same problem still. What would I be checking for there? How do I check relays?
    I put the voltmeter on the posts in the engine bay and got no reading. I apparently don't know how to work my new voltmeter. What setting should it be on? I turned the dial but no readings really. Might go straight to the battery and try there.
     
  21. jm3

    jm3 F1 Rookie

    Oct 3, 2002
    4,364
    United States
    Full Name:
    JM3
    #21 jm3, Apr 14, 2014
    Just put a new fan relay in it. It wont be a waste of time. Try to get a Delco one.
     
  22. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
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    goth
    #22 gothspeed, Apr 14, 2014
    Read some of these threads:

    This thread covers one of the fan/rough idle issue causes ...... the later model 355s have address this issue with a change to the intake duct design. Which separates the engine intake from the radiator intake.
    One quick way to test is to remove the cloth inlet tube from the inlet side of the LH air box and see if the roughness continues when the LH fan comes on.

    http://www.ferrarichat.com/forum/348-355/160040-355-spider-idle-stumbling-problem-solved.html

    This thread covers another common issue that causes poor running:

    http://www.ferrarichat.com/forum/348-355/377706-355-owners-only-more-data-samples-needed-anonymous-poll.html

    And if you have unshielded exhaust manifolds, this thread can help:

    http://www.ferrarichat.com/forum/348-355/425737-355-misfire-when-engine-hot-ignition-wire-reroute-shows-some-relief.html
     
  23. SoCal1

    SoCal1 F1 Veteran
    Owner

    Jun 14, 2011
    8,636
    SoCal LA/OC/New Mexico
    Full Name:
    Tim Dee
    #23 SoCal1, Apr 14, 2014

    I am going to steal your idea with the shroud. Great R&D

    Granted these cars suffer from thermal feedback with the rear engine/cooling.
    I'm surprised they don't go into a thermal loop at times. Shows some positive engineering for sure.
     
  24. ready321now

    ready321now Formula Junior

    Jan 5, 2013
    499
    New Jersey
    #24 ready321now, Apr 15, 2014
    Last edited by a moderator: Sep 7, 2017
    OK SO I looked at the fuse box under the passenger floor plate.

    I removed the relay for the LH fan, so that is the one missing from the bottom.

    It seems that there a lot of fuses and relays missing!!!! How does my car even run with these items missing? I am baffled.

    Here is what is missing:

    Fuses:
    #31 RH oxygen probe
    #32 Bank 1-4 injector ECU
    #23 RH fuel pump

    RELAYS:
    #L RH bank injector ECU
    #M RH fuel pump

    What is the deal here? How does the car even function with all of this missing from my 1997 F 355 spider? Any feedback would be much appreciated.
    Image Unavailable, Please Login
     
  25. johnk...

    johnk... F1 World Champ
    Owner

    Jun 11, 2004
    11,278
    CT
    Full Name:
    John Kreskovsky
    #25 johnk..., Apr 15, 2014
    It would seem that you are looking at the 1995 manual.
     
    Lionworks Auto likes this.
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