944S2 warm idle problem

Club News Forums 914/924/928/944/968 Forum 944S2 warm idle problem

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #1864
    pcaucr
    Keymaster

    guylajoie
    Posted:15-Jul-2012

    Another issue, I red alot on many forums about this common problem, but before changing the expensive ICV I need some opinions…

    Car was back from garage and have a new clutch.

    Drove home, and before putting the car in the garage, car almost stall with a rev bouncing up and down, oil pressure falling down.

    1. My needle on the temp gauge is very low in the dashboard, below the 1rst mark, and it is 93F outside when I drive the car. I had to keep the rev up or the engine would die

    2. Once back home, I revved the engine until the needle went all the way up, and I could hear the cooling fan functionning ; once the cooling fan started, the rev was consistant, with the needle all way up, no stall problem

    3. I changed the temp ensor, still same problem, wants to stall, but the rev is not bumping that much anymoreé

    4. have removed the relay and clean it like suggested in Clarck’s garage procedure to no aivail.

    As soon as the car reach normal temp, the idle decrease slowly and the engine bugs down, unless I rev it and keep my foor on the gas…

    I will try to bring the car tomorrow to We Tune where the clutch was changed, before the clutch change, the car was running normally at warm temperature..

    Mystère…

    #1865
    pcaucr
    Keymaster

    ottom
    Posted:16-Jul-2012

    did they forgot to re-connect something? like the O2 sensor?

    #1866
    pcaucr
    Keymaster

    guylajoie
    Posted:16-Jul-2012
    Modified:16-Jul-2012

    Nope, I found half the part holding the reference sensor on top of the transmssion housing, so the sensor ir free..
    Someone put some glue to hold the 2 parts When we left Charlevoix before the clutch failure, the car was running perfectly well at normal temperature, only when the car came back after the clutch installation, it starts was running bad. I had to take the 30 so the car would not stall at traffic light, and barely made it home last week on Thursday
    ..
    I will not name the shop, but it is in Montreal…

    #1867
    pcaucr
    Keymaster

    markusblaszak
    Posted:16-Jul-2012

    The reference sensor on the S2 at the flywheel is the speed reference sensor. This is for engine timing. I’m surprised it would run with this not located properly. The engine timing (TDC) is done by the sensor at the camshaft using a metal ring attached to the exhaust camshaft. I will suspect that your shop is not experience at working on the 4 cylinder water cooled cars. Everyone that is knows that the reference sensors project through a hole in the bell housing and MUST be removed before removing the housing to access the clutch. If they are not removed you either break the sensor or the sensor bracket. Looks like this is what happened to you as evidenced by the glue in your photo on the broken pieces. As a minimum, they should have replaced that sensor bracket for you (they are cheap) or TIG welded it together. Now the work must be repeated again to place the new bracket in there.

    Markus Blaszak
    Blaszak Motorsports

    #1868
    pcaucr
    Keymaster

    guylajoie
    Posted:16-Jul-2012
    Modified:16-Jul-2012

    When you say the work has to be done again??
    They do not need to removed the transaxle again just to replace the bracket right????

    #1869
    pcaucr
    Keymaster

    markusblaszak
    Posted:17-Jul-2012
    Modified:17-Jul-2012

    Well, it depends. The sensor bracket is bolted to the back of the block and then the bell housing is put on after the sensor depth is set using a feeler gauge off of the reluctor ring on the flywheel…. are you supposed to remove everything to get at the bracket? Yes…. Do you have to?… Depends…

    If it was removed when the clutch was done, and if the hardware is not seized, and if the bracket is not seized to the split dowel on the back of the block (aluminum on a spring steel dowel so it often corrodes), then you are lucky and can change it with the engine and transmission in the car. However if you are unlucky, then everything has to come out to get access to the bracket so it can be changed. If some of that epoxy got into the allen head bolts that hold it on the block, it will all have to come out. The amount of space to work back there is literally inches. Sometimes lowering the engine and front crossmember a few inches with everything still connected allows for enough room to work on it and get it apart. Resetting sensor height after the fact can be done with shims used as a 0.8mm depth spacer temporarily glued to the bottom of the sensor. Once height of the bracket is adjusted, this must then be removed.

    Any decent Porsche shop will know how to do this work. Just eluding to what you may be facing. Good luck!

    BTW, none of this has anything to do with your fans or temperature gauge. That problem is because you also have a poor ground at the end of your engine block (right near that sensor bracket). It is the smaller brown wire. You also more than likely have an air lock. Turn the heater to full HEAT while car idles and bleed at the bleeder fitting at the top front of the cylinder head with the radiator cap OFF. When all the air is out of the system, your fluid level will no longer change with the cap off. This you can do yourself since the shop did not do it for you. And while at it, ensure that you have the PROPER coolant in your car! It should be Phosphate and Silicate free. If it is green, it is the WRONG coolant!

    Markus Blaszak
    Blaszak Motorsports

    #1870
    pcaucr
    Keymaster

    guylajoie
    Posted:17-Jul-2012
    Modified:17-Jul-2012

    Without a proper speed reference sensor signal, the DME relay keeps dropping out. Without fuel and ignition yes, the car does not run very well.
    Why is there air in the system? I will guess because they removed the upper coolant hose from the rear of the cylinder head to the heater core in order to access the upper bell housing bolt easier. Doing this causes you to lose coolant and the resultant air in the system.
    Also, when the ground for the sensors at the back of the engine block is loose, you get poor running as well as erratic gauges.

    If your Porsche shop is unaware of these items, then perhaps they are not familiar with the 4 cylinder water cooled cars and you may wish to get your vehicle serviced else where.

    Markus

    #1871
    pcaucr
    Keymaster

    guylajoie
    Posted:17-Jul-2012
    Modified:17-Jul-2012

    Well according to me, they mess up fisrt time, so I do not want to pay again for their mistake…Charging me for a part they broke and did not change when they could…
    Can I start the car with halg the part missing or may I damage the engine.
    To tow the car, I have to get the car out of the garage..
    I’m afraid to break something more….

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