Exhaust Problem 360 Modena | FerrariChat

Exhaust Problem 360 Modena

Discussion in 'Technical Q&A' started by MD355, Feb 19, 2012.

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  1. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
    Full Name:
    MD
    I am experiencing a problem on my '02 360 Modena (stock exhaust setup)...

    After a service and clutch replacement (the clutch bearing was bad and decided to replace clutch as well, it now works very smoothly !!!) the car starts very quiet... No startup boom, and the rpm settle immediately to 1100rpm...
    You can hear the engine sound as opposed to the exhaust sound which is very quiet.

    Also when I start driving the exhaust valves seem to be closed all the time, even under load on 2nd and 3rd gear... They only open under load (2nd & 3rd gear and above) briefly and above 6k rpm... First gear they remain closed all the way to 8k rpm !!!!!

    Not normal, compared to before service & clutch replacement... They used to open all the time from 3k rpm at 2nd & 3rd gear even at 70% load and the exhaust would produce the typical metallic "bark"... Also upon double de-clutch, the exhaust valves used to open up and I would hear cool mini explosions in the exhaust... Not anymore, it just revs with exhaust valves closed ... :-(

    Does anyone know the cause why my car is so mild and quiet now ???

    My mechanic insists that the system works fine and there is nothing we can do, since it is mechanical (works from engine vacuum)... We removed the exhaust valve connector to test the valves and they open just fine... Only problem is I don't want to drive my car with valves open all the time... I want my car they way it was before service & clutch replacement... Valves closed and opening under load as the system was designed !!!

    Any thoughts ??? Thanks !
     
  2. plugzit

    plugzit F1 Veteran
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    Possible kinked or partially blocked vacuum line? Otherwise, I don't see how this can happen, as it opens with LESS vacuum (WOT). Seems if there is a bad installation, it would open more rather than less. I'm no expert, tho.
     
  3. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    Exactly ! That's what I think too...
    Could it be that the system was leaking before the service and now it is working properly and is more restrictive ?

    Also, I noticed that when I removed the exhaust valve actuator and the valves remain open at idle, that exhaust is louder but not as loud as when they were open before the service...
     
  4. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
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    It seems like there is less exhaust gases coming from the exhaust then before the service...
    If that makes any sense...
     
  5. 360trev

    360trev F1 Rookie
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    #5 360trev, Feb 19, 2012
    Last edited by a moderator: Sep 7, 2017
    The operation of the Pneumatic Actuating System will fail to work properly if the connecting pipelines are not in good condition - i.e. they must be without excessive bends, blockage or tears. That's the first place I'd check for if your experiencing problems.

    Modular Manifold
    The system is made up of two solenoid valves (1) and they are attached to the Bosch Motronic Ignition computers supporting bracket and connected, by means of pipes (2), to the vacuum tank (3) which is found under the right-hand rear mudguard.

    The engine ECU determines the opening of the solenoid valves, which, in turn, control the pneumatic capsule (4) and the actuator (5), both of which are positioned on the plenum chamber. The pneumatic capsule (4) controls the compensating throttle through a system of levers. The actuator (5) activates the intake manifold throttles, using an idler arm and ball-jointed stay rods. Note that sometimes this can become stiff or loose, its another point worth checking for correct operation.

    Exhaust by-pass system
    The system is composed of two solenoid valves (6) fastened to the chassis, on the rear part of the engine compartment. These solenoid valves are both connected to a pneumatic throttle valve (7), fitted on the exhaust terminal, and to the vacuum tank (3). The Motronic ECU for bank 1-4 determines the opening of the solenoid valve according to the engine revolutions and the engaged gear.

    Check for any leaks from any of these pipes.
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  6. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    Thanks for your detailed explanation and excellent diagrams.

    I am starting to think that there is something else wrong instead of the exhaust bypass valves.

    When I disconnect the exhaust valve actuators (exhaust open all the time) the noise of the exhaust at idle speed is not as loud as I remember prior to the service.

    Even though idle is at 1100rpm as before, it seems as if the engine is not producing enough exhaust gases to make the same sound as before.

    In terms of performance, acceleration is very linear all the way to red line, as opposed to linear acceleration until 5000 rpm and super fast acceleration combined with amazing sound all the way to redline before.

    I am starting to think that it could be slightly bad timing, since this story started right after timing belt change...

    I started a whole thread about possible bad timing, but the dealer would not admit to it.
    The independent Ferrari mechanic found nothing wrong with timing too.
    And he also said that the exhaust valves work just fine.

    So it's back to the dealer this time with audio / video footage that I found before and after the timing belt change, and maybe a direct comparison with another 360 at the service floor of the dealer...

    Has anyone experienced different sound due to bad timing, while at the same time the engine appears to work normal ?
     
  7. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
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    After doing a search on Ferrarichat I came to the following conclusion...

    Based on this thread :

    http://www.ferrarichat.com/forum/showthread.php?t=43785


    I think that at the last major service (timing belts changed) the dealer messed up the timing between the 2 cylinder banks. (The problem started right after major service)

    While the timing is not very off to show any error code (the variators fix part of the problem) it is enough to make the engine work as two 4-cylinder engines with different timing, as opposed to one flat plane V8...

    - At idle the two 4-cylinder banks work at different intervals, therefore the noise from the exhaust is less, since the exhaust pulses do not coincide in the muffler to create a boom effect. Furthermore, I noticed that the exhaust gases, while the are the same in volume, the do not come out of the the exhaust pipes with the same pressure and do not travel out from the exhaust as far as before, they just go up with low pressure... (they were visible due to cold weather)

    - Under load the engine pulls strong, but not as strong as before and since on of the two or both banks are off timing, they do not generate enough vacuum for the exhaust valves to open normally and the engine to produce the "Ferrari magic" sound...

    - At Wide Open Throttle at high rpm, sometimes it appears as if there is not enough vacuum again to keep the exhaust valves completely open...

    The problem does not trigger any problem on the computer and the test they performed at the dealer showed that the variators work correctly... However, only if the timing thoroughly checked again can we see if they are set at the proper factory 657/657 (right/left bank) +/- 2 degrees based on the above thread...

    Any thoughts are welcome... Thanks !
     
  8. rustybits

    rustybits F1 Rookie
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    This can't happen for two reasons. Firstly, if the engine timing was out enough to cause internal vacuum issues your engine warning light would be on. Secondly, the valves don't take their vacuum source directly from the manifold. There is a very large vacuum reservoir mounted underneath the r/h wing, which takes a long time to be exhausted. Those valves are switched on electronically by the Motronic units which then allows the vacuum to be pulled through from the valves.
     
  9. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
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    Thanks rustybits !

    What you are saying makes sense.
    However, why am I missing the typical 360 V8 metallic bark ?
    Why does my car sound like two 4-cylinder engines ?
    At idle the exhaust (even with exhaust valves actuators disconnected = valves open) is very mild... You can hear the engine sound on top of the exhaust sound, which is not normal for this car...

    When does the motronic trigger the the actuators to open ?

    When the engine is under load right ?

    Could the engine be "less under load" if the the timing is off...

    I don't know, so I am just guessing, so please be kind... Thanks !
     
  10. windsock

    windsock Formula 3
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    Nov 29, 2006
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    Checking for the 657/657 electronically will only check half of the camshaft timing (exhaust camshafts) There is no way to properly check the intake cams unless you pull the cam copvers and use a degree wheel and dial indicators. Using the factory assembly marks is not accurate enough I have seen them off ten degrees. This is a common occurance when getting the budget cam belt swap rather then a proper job which should include degree/index of the camshafts.
     
  11. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    Thanks windsock for your explanation !

    Is it possible to have the exhaust valve timing correct and have messed up the intake valve timing ?

    The dealer insists that they checked the timing (probably exhaust valve timing) and it is correct.

    Should I push on this issue and insist that they check intake cam timing too ?

    Do you think the symptoms of my car could be attributed to wrong timing ?
    (lack of proper flat plane Ferrari V8 sound, milder and more linear acceleration, hesitation of opening of exhaust valves even under full engine load... etc)

    Don't forget that everything started after a major timing belt change...

    Thanks again !
     
  12. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
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    I should add to the symptoms that my car seems to be "running out of breath"...
    (not as free revving as before belt change)
     
  13. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    Question : I spoke with a friend that has owned Ferrari over 20 years and he told me that it could be a broken catalytic converter, a blocked fuel pump or decreased compression from one of the cylinders (maybe clogged valve)...

    He said it could not be timing, because I would have rough idle, which I don't have...

    My car doesn't pull as strong and sounds weak (it take too long for exhaust valves to open at higher rpm than before)...

    What do you guys think ?

    Wouldn't any of the above give trigger some error code on the ecu ?

    P.S. My car has just 26,000 km , is used on a weekly basis and has always been properly maintained and serviced.
     
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  14. windsock

    windsock Formula 3
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    Yes to all those possibilities you mentioned but if the concern occured after performing a service the smartest thing to do is backtrack and find the error or concern. Now you must allow someone the time to properly diagnose.
     
  15. FerrariDublin

    FerrariDublin F1 Rookie

    Jun 14, 2009
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    MD, I had a problem with the car a while ago and the first symptom was poor sound in terms of the high pitched scream it should make. I had no CEL and the idle was not obviously rough. The cat on one side was glowing brightly and it turned out that I had a misfire on just one cylinder. The miss was not obvious in terms of seat-of-the-pants feeling but that one cylinder being out was the problem and once I'd sorted out the short the scream was back.

    I'd suggest you go drive the car at night and when up to temperature pull over and pop the engine bay lid. You will probably see a little glowing around where the O2 sensors go into the cats (on a healthy one) but if the entire cat is glowing you have a problem.
     
  16. plugzit

    plugzit F1 Veteran
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    This is beginning to sound like a problem with a blocked cat. If one was dropped during service (think lowly paid assistant who didn't tell the chief mechanic), it could have broken the ceramic honeycomb. A blocked cat will make the car run out of steam at higher rpms. Haven't yet thought through what it would do to vacuum. It's almost always the simple answer. If two mechanics have verified the timing was ok, and I tend to believe that any competent mechanic will get it at least close, I'd move on. Variator?? No idea if that, by not changing cam timing at x rpm, could make it dramatically worse. There's got to be a simple check. Maybe check threads on that while putting off removing the muffler to look in the cat.
    Strongly suggest you send me a ticket to Europe so I can check it out! :)
     
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  17. rustybits

    rustybits F1 Rookie
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    +1. There have been a lot of suggestions here, some good, some not but I'd get it back to the shop who did the work and get them to look again.
     
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  18. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    Thanks guys for your support !

    windsock & rustybits : You are correct that the right thing to do is to go back to the dealer... Only problem is that the dealer insists that everything is fine with the car and that there are no error codes...

    So I need to explore the other alternatives...

    plugzit : If a catalyst was blocked, wouldn't there be a CEL or a Slow Down warning due to the increase in the temperature of the blocked catalyst ?

    FerrariDublin : I am amazed by what I saw in your thread about the engine coolant short-circuit on the spark plug of the engine ! How did your engine respond ? Was there any error code on the display or on the dealer computer ?

    Any idea how the engine would behave if there was not enough fuel pressure from the fuel pumps ?

    Thanks again !
     
  19. FerrariDublin

    FerrariDublin F1 Rookie

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    #19 FerrariDublin, Feb 22, 2012
    Last edited: Feb 22, 2012
    Yes, that seems to have been a somewhat unique misfire problem! When I suffered that I was aware that something was up but couldn't nail it down simply by driving. The car was sounding/feeling a little rough but was ticking over pretty well and pulling reasonably hard. It's possible the spark was igniting properly every other time above or below certain RPM.

    I got no CEL, there were no codes thrown (as can happen without a CEL having been lit) and I did not get a Slow Down warning even though one of the CATs was most certainly at a very high temperature. It's possible the lack of SD warning was due to the relatively short drives I took while I was suffering and trying to diagnose this problem.

    I'm not suggesting for a moment that you might have the very same problem, just pointing out that with even just one cylinder down (for any number of reasons) you would very likely suffer the symptoms you describe and without any warning lights or codes being thrown.

    If you had low fuel pressure I suspect you might very well suffer the same kind of symptoms. Overall feeling of lack of power. Lack of "edge" to the exhaust note. I guess your plugs would likely be a very light tan or even grey/white color. Your exhaust tips might also be unusually light grey. I'd expect your long term fuel trim (available from OBD2 readings) to indicate positive trim of high percentage and probably short term in the high positive also.

    p.s. FWIW the long term trim on my 360 seems to run at circa +5% on each bank. I have seen as high as +10.2% in the past. I put this down to having replaced the OEM for a free-flowing back box.
     
  20. Aj360

    Aj360 Karting

    Dec 28, 2018
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    Hey guys bumping a old thread here but I am trying to work out some exhaust stuff to myself on my 360.. just had my timing belts done oil filters plugs new maf sensors and various other things done .. I have a capristo free flow sound 3 on the car stock cats and headers .. my car is a euro no header cats ‘ my car sounds amazing when you rev it sitting still but when driving it sounds very underrated ?? At 4000rpm I can get a faint f1 creeping in but Soon as it goes over 4000 there’s no nice flow it sounds some what ruff like it’s struggling to get to those high revs . I am pointing to a exhaust leak or something. But anything else you guys could point me to check would be huge ..
     
  21. MD355

    MD355 Formula Junior

    Mar 8, 2004
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    Hi !! I am the original poster of this thread. It took my 5 years to sort the problem. The finding was that during the timing belt change at the dealership, the timing was messed up. I went to 2 mechanics who tried to bring it close to factory specs and after 2 attempts (removing cylinder valve covers and using dial gauges and degree wheels) , I finally found an experienced mechanic who fixed the timing, 5 years later). The easy check is for the exhaust camshaft. Plug in the computer diagnostic and it should be 657/657 (right/left exhaust camshaft)
    For the intake it is more difficult...
    Try the exhaust and you should get an good ideal what is going on. Good luck
     
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  22. Aj360

    Aj360 Karting

    Dec 28, 2018
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    Hey man I just posted a thing about my dramas with my 360 haha man it seems like timing cause It needed the belts done did them and it is having the problems looks like retiming is what’s needed I will get the diagnostics done see where it’s at and let you know fingers crossed man thanks for the info to it’s much appreciated.. one question was your 360 not sounding proper under load like it’s got no f1 tone ?? Sounded rough ?
     
  23. MD355

    MD355 Formula Junior

    Mar 8, 2004
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    After the timing belt change in December 2011 my Ferrari 360 sounded like crap... It had lost all of its power... It struggled to rise the rpm and sounded like a sewing machine (stock OEM exhaust) Furthermore, at idle it was weak.. It has lost the energy which the exhaust fumes exit the exhaust system !!
     
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  24. Aj360

    Aj360 Karting

    Dec 28, 2018
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    Man my belts just been done ...sounds exactly like your saying yours did .. on idle it’s up and down cold start it stays high idle then it drops ... the tone is not to good I got the capristo free flow sound 3 as well .. if I rev it sounds ok standing still but driving under load sounds not to good :( mine struggles to get up the revs to and is running rich Is not a fun drive lol
     
  25. MD355

    MD355 Formula Junior

    Mar 8, 2004
    794
    Athens, Greece
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    MD
    The same symptoms as mine back in 2011 after the belt service... I revved fine standing but under load and at idle is sounded like crap...
    Check the timing on the exhaust side with the Ferrari OBD Diagnostic (I think it's called Leonard0) or some compatible system... Check the video below at 1:24 minutes...
    It says 656 degrees which very close to the ideal 657 !!!

     
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