924 carrera GT seized engine

Club News Forums 914/924/928/944/968 Forum 924 carrera GT seized engine

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  • #1890
    pcaucr
    Keymaster

    stevebennett
    Posted:07-Oct-2012

    I imported a 1981 924 Carrera GT ( one of the 406 made) into Canada in 1996. It ran perfectly at this time. In 2000 I sold it to a friend who ran it for a few years until the turbo failed. He put the car in his barn, removed the turbocharger but never got round to fitting the new one. I bought the car back a few months ago and the engine appears to be seized. I have had a bar on the main crankshaft – no movement. I have been towed slowly along the highway and have tried to crank the engine by releasing the clutch – the back wheels skid along the road. The car has been in a dark, dry barn for 10 years – the engine should not have seized like this. I have poured all kinds of freeing agents/concoctions into the cylinders. Someone suggested the clutch could be seized. I have moderate knowledge of engines ( not too much on Porsche) . Without stripping down the engine and emptying my bank account, does anyone have any suggestions on the next step? I am in the Peterborough Area.

    #1891
    pcaucr
    Keymaster

    andywright
    Posted:08-Oct-2012

    Hi Steve
    If the clutch were seized, you wouldn’t be able to engage/disengage the transmission as you describe in your “highway test”.
    When the Turbo failed did any bits get loose and get blown into the cylinders? That might cause pistons to jam.
    As this stage you are into an engine stripdown anyway, even if you did get the engine to turn over. Obviously something is seriously wrong and even if the pistons or bearings did free up enough to allow the engine to turn over there would likely be damage to the bores or crank.
    I would start by removing the cylinder head which might give you a better idea of what has happened. If nothing obvious is found the next step is to drop the oil pan (not sure if this can be done in-situ) and remove the crank bearing caps to see if the pistons free up or the crank will turn.
    Good luck!
    Andy

    #1892
    pcaucr
    Keymaster

    andywright
    Posted:08-Oct-2012

    Another thought.
    A very limited production model such as yours deserves to be repaired correctly, especially if it has the original engine.
    I can certainly relate to budget concerns, so if a full engine rebuild isn’t on your Bank Managers agenda right now, why not try to find a regular 924 Turbo engine so at least you can get the car mobile again.
    Just a quick browse found this one on eBay: http://www.ebay.com/itm/73-PORSCHE-TURBO-ENGINE-5-SPEED-MANUAL-TRANSMISSION-1982-924-/320992538823?pt=Motors_Car_Truck_Parts_Accessories&hash=item4abca570c7&vxp=mtr

    #1893
    pcaucr
    Keymaster

    clarencedam
    Posted:08-Oct-2012

    I agree with Andy. Have you checked to see if the timing belt is properly in place? You could also eliminate the alternator and A/C compressor by removing those belts and try to turn it. If you did use a 924 turbo engine temporarily, the addition of your Carrera intercooler and a modest boost increase would give you better than than stock 924 turbo performance.
    You have a very special car, I hope you can find a way to fully repair the damage.
    I would love to see it some day.

    Clarence

    #1894
    pcaucr
    Keymaster

    stevebennett
    Posted:10-Oct-2012

    Hi Guys, thanks for the replies and support.
    When the turbo failed I do not believe it was “explosive” – the car was driven home and then put in the barn – I dont believe there would be any pieces inside the cylinders.
    The timing belt is properly in place – the camshaft does move slightly indicating that the problem is with the main crankshaft. I have removed the alternator/water pump belt, and there is no A/C compressor.
    Removing the oil pan sounds like the next step – does anyone know if this is possible?
    A reply from a different forum goes as follows:
    “While it is a possibility that you have a seized engine, you first need to determine the cause of the engine not rotating. I would suggest that before you start to dismantle things you decouple the transaxle from the drive shaft (by removing the bolts on the coupler and sliding the coupler towards the transaxle) to see if that frees up the engine. If that doesn’t, then there is still a possibility that either the clutch or the starter is locking the flywheel (and keeping the crankshaft from turning). If that is not the case, then it looks like removing the engine in order to diagnose what is keeping the crank from turning. Remove the engine and place it on an engine stand, then start removing parts until the crankshaft will turn. The last thing you remove before the crankshaft frees up will have been the cause of the seizure.”
    The starter has been removed. I dont understand how the clutch could jam the flywheel – can anyone shed any light on this?
    Steve

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