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355 Strange noise at front of engine?

Discussion in '348/355' started by 355OXO, Feb 27, 2021.

  1. 355OXO

    355OXO Karting

    Apr 16, 2006
    150
    UK
    Full Name:
    Simon
    Ferrari 355 Spider,
    I have recently had a major belt service. After about 800 miles my car developed this noise at the rear left side front of the engine. At first I thought it was and maybe it is a bearing.

    Dropping petrol tank to investigate. Has anyone experienced any rubbing at the front of the engine on the fiberglass petrol tank protector shield? The clearance is very tight between the belts and shield in my opinion.

    Car has new water pump, alternator Hills bearings. I have used a stethoscope and i think the noise emanates from the fiberglass tank shield.

    Any thought or input appreciated.
     
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  3. A348W

    A348W Formula 3

    Jun 28, 2017
    1,455
    North Wiltshire, UK
    Take it back to who ever did the major would be my first route.

    If you mean the cam belt covers, they are tight and I’m sure if not put back right will rub.

    Personally I wouldn’t be dropping the fuel tank as that has its own issues.
     
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  4. SoCal1

    SoCal1 F1 Veteran
    Owner

    Jun 14, 2011
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    Tim Dee
    wrong tensioners, water pump or something like that, Common mistake
     
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  5. Qavion

    Qavion F1 Veteran
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    Feb 20, 2015
    5,121
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    Ian Riddell
    The previous owner of my car didn't fit the belt covers properly and at least one my belts started shredding. See if there are small pieces of rubber around the bottom of the covers (small crumbs or granules).

    rear front side? o_O
     
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  7. 355OXO

    355OXO Karting

    Apr 16, 2006
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    UK
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    Simon
    The service was done by a UK Maranello guru who knows 355 intimately and is a renowned expert. The reason i have not taken it back is that i don't want to drive it and cause any damage. I purchased a stethoscope and i am now fairly sure that the auxiliary belt is rubbing on the fiberglass tank protector that is causing the noise.
     
  8. 355OXO

    355OXO Karting

    Apr 16, 2006
    150
    UK
    Full Name:
    Simon
    The service was done by a UK Maranello guru who knows 355 intimately and is a renowned expert. The reason i have not taken it back is that i don't want to drive it and cause any damage. I purchased a stethoscope and i am now fairly sure that an auxiliary belt is rubbing on the fiberglass tank protector that is causing the noise.
     
  9. 355OXO

    355OXO Karting

    Apr 16, 2006
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    Simon
  10. 355OXO

    355OXO Karting

    Apr 16, 2006
    150
    UK
    Full Name:
    Simon
    No not the cam belts or covers, thanks.
     
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  12. 355OXO

    355OXO Karting

    Apr 16, 2006
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    UK
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    Simon
    I have checked for rubber around the bottom. The service was done by a UK Maranello guru who knows 355 intimately and is a renowned expert. The reason i have not taken it back is that i don't want to drive it and cause any damage. I purchased a stethoscope and i am now fairly sure that an auxiliary belt is rubbing on the fiberglass tank protector that is causing the noise.
     
  13. A348W

    A348W Formula 3

    Jun 28, 2017
    1,455
    North Wiltshire, UK
    Which “expert” is this? Come across a few!

    If it’s the cam belt covers, it might well be something that can be sorted at home and the “expert” can come and do it; else get it transported back; doesn’t cost a huge amount and if it’s a fault by the garage they should be covering the cost.
     
  14. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
    10,631
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    Mitchell Le
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  15. marioz

    marioz Formula 3

    Nov 21, 2003
    1,839
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    Mario
    Sorry for the bad memories yelcab
    It was a very informative thread though.
     
  16. 355OXO

    355OXO Karting

    Apr 16, 2006
    150
    UK
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    Simon
    I have not dropped tank yet but I am preparing to do so, The noise is a growling sound, non metallic in nature. I have put the stethoscope on all the major parts, Air con pump, alternator, varius engine points and Hills bearings. The noise emanates from the left front side of the engine when sitting in the car (Note RHD). The noise is worse on deceleration but makes a rumbling sound when accelerating. with the stethoscope the noise can be heard on the fiberglass tank protector and the petrol tank. It is constant just noiser driving.
     
  17. SoCal1

    SoCal1 F1 Veteran
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    Jun 14, 2011
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    Tim Dee

    I think the car may have the Rona LOL
     
  18. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
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    I would not drop the gas tank unless more definite causes are found. A growling noise while the car is moving can be a CV bearing, or rear wheel bearing (left side). Did you test out the CV axle theory? Turning in one direction is worse than the other direction.
     
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  19. 355OXO

    355OXO Karting

    Apr 16, 2006
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    Simon
    The noise can be heard when stationary too so unlikely to be CV's.
     
  20. spaghetti_jet

    spaghetti_jet Formula Junior

    Jan 5, 2005
    598
    Europa
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    Bob
    #18 spaghetti_jet, Mar 1, 2021
    Last edited: Mar 1, 2021
    Perhaps the simplest thing to do would be to try and get a camera in there and see if there is anything physically touching the firewall. You can buy USB inspection cameras for around €40 or use an old phone and a selfie stick to film from underneath looking upwards & down the sides of the engine bay. If nothing is physically touching the firewall then its most likely a belt or bearing.

    If nothing is visibly touching then you could start by disconnecting the drive belts to the ancillaries one by one and see if the noise goes away. For example, I had a grumbling noise a few years ago and it was the alternator belt tensioner pully bearing that had gone bad. The tensioner is on the right hand side of the engine, so may not be your problem, but it's just an example.

    This is a lot less trouble than dropping the fuel tank that in itself has a whole host of other implications.

    On the other hand, if something is touching the firewall then you need to understand why in a hurry -- nut come off a pulley allowing it to move? engine mounts?? etc. etc. Anything touching the firewall could get mighty expensive very quickly if it flies off, shreds a belt etc.

    If there is nothing touching and disconnecting the accessory belts doesn't eliminate the noise, then it's probably engine out time for a closer look...
     
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  21. kenneyd

    kenneyd Formula 3
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    Sep 30, 2014
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    I agree with the above comments to just remove the accessory belts and see if the sound goes away. Other than that,

    Two other things to try.
    One check the belt tensioner on the alternator and accessory belt.
    It is possible that it may not be spinning and/or the bearing is bad due to overtightening..

    Two it is also possible to misalign the air conditioning belt.
    When I put mine on, initially I had it one rib over which makes it conflict with the other belt just slightly. It never made noise, but I noticed a little bit of powdery rubber after just a few miles. Easy fix.

    The only problem is neither one of these would make a bad grinding sound like you're describing. I wouldn't drive it until I figure out what exactly that is
     
  22. 355OXO

    355OXO Karting

    Apr 16, 2006
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    Simon
    Following further investigation, I have found the problem now, the auxiliary belt that drives the aircon, alternator and water pump was slightly rubbing on the fibreglass panel that separates the front of the engine from the petrol tank. It was an odd problem as it had recently had a new water pump and belts. The belt had slipped off the water pump pully slightly hence the reason it was touching the fibreglass protection panel. I have now removed and inspected this belt for any damage. Luckily it was still in perfect condition. I have now refitted it in the correct position and tensioned this belt correctly. I am hoping that this will resolve the problem from reoccurring. The new water pump was a pattern part from Eurospares and these have performed well within the UK market.

    This has resolved the noise I could hear. Thanks for all your help and input.
     
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  23. 355OXO

    355OXO Karting

    Apr 16, 2006
    150
    UK
    Full Name:
    Simon
    I have now realigned the auxiliary belt that was rubbing on the fibreglass protector for the petrol tank at the front of the engine. The problem I’m having now is that the belt will not stay in the correct position on the water pump pulley and keeps slipping off slightly causing it to rub again on the fibreglass protector.

    The water pump is new and there is no serious play on the pulley. The tensioner roller for the auxiliary belt appears to be square in the correct position.

    Once everything is aligned I run the car for a couple of minutes and the auxiliary belt slips off the water pump pulley slightly. I cannot work out what is causing this. Any ideas or input will be helpful?
     
  24. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
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    The problem is the three pulleys on that belt are not on the same plane: The water pump, the crank shaft pulley, the alternator pulley have to be on the same plane or you get the walking belt. Find out why. You got a new water pump, is it for the 355? Or is it for the 360? Did they get the water pump pulley on all the way? Was this shop a Ferrari shop?
     
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  25. MAD828

    MAD828 Formula 3
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    Oct 8, 2011
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    Elliott Caras
    I had this problem. The heat shield dislodged and was rubbing the water pump. That was fixed and the belt replaced. Still the belt was walking and getting frayed. When I pulled the engine out for its major I identified what had gone on. Someone in the past had overtightened the belt pulley and snapped the adjustment screw. Instead of replacement they just welded it together and it was askew. This meant that the tensioner was ever so slightly out and would make the belt wear. Once replaced (also had to replace the mount as it was cracked) had no issues.

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  26. Ferrari Fanatic

    Ferrari Fanatic Formula 3

    Apr 2, 2003
    1,259
    SoCal
    That tensioner adjusting bolt is known to break even without over tightening it. I recall that when you loosen the bolt, by design it tightens the tension. Anyway, when the bolt is turned, instead of tightening the belt, it will just cock at an angle !

    Take a closer look at how your tensioner reacts, and if see if it goes out of alignment when you tension the belt. It very well could just cock at an angle as the bolt is bent.

    If you do need to replace the bolt, it’s not very technical, but very Italian and fun to change ! Some changed the 3 studs to bolts, but not really necessary.

    If you do remove the tensioner, let us know if you start cruising in Italian and/or need some tips.

    Recambi had the bolt and the pulley in stock but that was a couple years ago (saw a thread and will skip that subject, Daniel is a great guy ). If your bearing is questionable while your in there, and opt to replace it: If you have the pulley that is serviceable, the bearing is pretty standard and easily sourced. It’s also pretty easy to get the bearing in and out of the pulley.

    Hope that helps.
     
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  27. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    I'm have a little problem understanding how the tensioner would make the belt run off the WP. The tensioner is between the crank and alternator pulleys. The belt makes a strait run from alternator to WP to crank pulley. If it's running true on the alt and crank the only reason I can see for it to walk off the WP pulley, if it is properly tensioned, is as Yellow cab said; It must not be in the same plane as the other 2 pulleys, or there is something wrong with the pulley. Plus, it's a grooved belt so if it ran off the WP pulley it was likely damaged and it needs to be replaced.
     
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