328 idles rough after coolant hose replacement..air in system? | FerrariChat
Buy

328 idles rough after coolant hose replacement..air in system?

Discussion in '308/328' started by Gilgamesh76, Jun 3, 2024.

Tags:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Gilgamesh76

    Gilgamesh76 Rookie

    Mar 2, 2024
    10
    #1 Gilgamesh76, Jun 3, 2024
    Good day! I recently replaced the coolant hoses under the plenum on my 328 due to some major leakage. While the car was apart, I also replaced the thermostat. After putting it all back together, the fuel pump started leaking, so I replaced that and the accumulator. The good news...she doesn't leak at all. The not so good news is she is idling really rough BUT once she is warmed up (coolant and oil temps at center of the gauges), it runs perfectly.

    I'm no mechanic, but my initial thought was air in the coolant system. I did bleed the the system by the thermostat and coolant came out...no air. I also took the cap off the reservoir...no extra air.

    Any thoughts on what might be going on? Appreciate any leads you may have...thanks!
     
    miketuason likes this.
  2. miketuason

    miketuason F1 World Champ
    Owner Silver Subscribed

    Feb 24, 2006
    15,773
    Cerritos, CA.
    Full Name:
    Mike
    #2 miketuason, Jun 3, 2024
    Did you also bleed it at the radiator? You might have to bleed it several times.
     
    Gilgamesh76 likes this.
  3. kiwiokie

    kiwiokie Formula 3
    Silver Subscribed

    Aug 19, 2013
    1,539
    Tulsa, OK
    Full Name:
    John McDermott
    #3 kiwiokie, Jun 3, 2024
    Not sure air in coolant would result in rough running when engine is cold. Seems more likely something has been dislodged while doing your maintenance work (like a cold start valve connection) or the new fuel pump and accumulator is resulting in a different control pressure.


    Sent from my iPhone using FerrariChat
     
    Steve Magnusson, mike996 and Gilgamesh76 like this.
  4. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,599
    California SF bay area
    Full Name:
    Paul
    #4 kcabpilot, Jun 3, 2024
    I assume you had the plenum off to get to the hoses so either you've got an intake leak or something didn't get plugged back in or hooked up right. Give it another visual once over, it might be obvious. It definitely doesn't have anything to do with coolant so you can scratch that off the list.
     
  5. Gilgamesh76

    Gilgamesh76 Rookie

    Mar 2, 2024
    10
    #5 Gilgamesh76, Jun 3, 2024
    Thank you! I did take the plenum off. Never hurts to double check all the connections.
     
  6. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,413
    San Carlos, CA
    Full Name:
    Mitchell Le
    #6 yelcab, Jun 4, 2024
    Not too many electrical connections under the plenum, but there are quite a few vacuum lines under the plenum and connected to the plenum. Double check those. See if the AAV is good and tight.
     

Share This Page