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Thread: Cranshaft key - car (Qashqai DCi)

  1. #31
    Should Get Out More irie's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Druid
    If you have bent a valve then the engine is probably toast.

    Quote Originally Posted by Ant
    Not necessarily
    Druid did not say necessarily, he said probably.

    Quote Originally Posted by Druid
    It is common for the camshaft caps to break when the valve hits the piston

    Quote Originally Posted by Ant
    Not always


    Druid did not say camshaft caps always break, he said it was common for them to do so.

    Quote Originally Posted by Druid
    which means a new head

    Quote Originally Posted by Ant
    No it doesn't. Heads are easy to strip and replace parts


    They may be easy to strip and replace parts but it is more often than not more cost/time effective to use a refurbished part. Maybe not for you but for ordinary mortals of course.

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  3. #32
    Really Bored Druid's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Ant View Post
    Not necessarily



    Not always



    No it doesn't. Heads are easy to strip and replace parts
    irie has answered the first two points.

    The cams run directly in the head there are no replaceable bearings. The cam journals are line bored and the bearing caps are not available separately. So if you have even one broken camshaft cap then you will need to replace the entire head. I know about this particular engine because I have had to deal with exactly these issues. You obviously don't have experience with this particular engine.

    If you are going to reply to this post please take the time to read it properly.

  4. #33
    Should Get Out More Mussels's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    I've ground valve seats once before, considering the cost of a refurbished head I'm never attempting valve grinding by hand ever again. Cleaning the old head gasket off is about the hardest job I'd want to do there.
    Plenty of older engines wouldn't knacker the valves if the timing was out but I suspect with closer tolerances nowadays it is more likely, not something I've given much thought to though.

  5. #34
    Should Get Out More Ant's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Druid View Post
    irie has answered the first two points.

    The cams run directly in the head there are no replaceable bearings. The cam journals are line bored and the bearing caps are not available separately. So if you have even one broken camshaft cap then you will need to replace the entire head. I know about this particular engine because I have had to deal with exactly these issues. You obviously don't have experience with this particular engine.

    If you are going to reply to this post please take the time to read it properly.
    ooooOOOOooo!

    I've worked on heads before, including vvt heads. Nothing to be so scared of.

    Never had one I couldnt replace parts on. Usually the valves are so hot that when they bend and the caps are fine.

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    Should Get Out More Ant's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Mussels View Post
    I've ground valve seats once before, considering the cost of a refurbished head I'm never attempting valve grinding by hand ever again. Cleaning the old head gasket off is about the hardest job I'd want to do there.
    Plenty of older engines wouldn't knacker the valves if the timing was out but I suspect with closer tolerances nowadays it is more likely, not something I've given much thought to though.
    Grinding by hand? Who does that these days.

    And you'd still need to clean the gasket material off the block though. Careful scrape and oil stoning.

  7. #36
    Really Bored Druid's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Ant View Post
    ooooOOOOooo!

    I've worked on heads before, including vvt heads. Nothing to be so scared of.

    Never had one I couldnt replace parts on. Usually the valves are so hot that when they bend and the caps are fine.


    What's that saying about arguing with idiots?

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  9. #37
    Should Get Out More Ant's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Druid View Post


    What's that saying about arguing with idiots?
    Who's arguing?

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    Should Get Out More lloyd_christmas's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by khd View Post
    My focus timing pulley has no key, once you remove the bottom pulley the timing gear will
    just spin. It is held tight by the pulley bolt which is a stretch bolt , torque up then tighten
    another 90 degrees.
    Looking at yours I would fit a new key and chemical metal to worn left side as Cheb says.
    The wife's Megane is the same, although the crankshaft still had a key-way, the pulley was key-way-less.

    From memory it was 45Nm + 135 degrees; my torque wrench broke when tightening it (didn't click) and i didn't want to restretch it so ended up with random torque plus a random number of degrees until it felt tight-ish.

    I was understandably a little on edge taking it for a shakedown run when at 70mph on the A46 there was a tremendous metallic clattering up front as (presumably) a forgotten spanner dropped down through the engine bay and twatted the bottom of the car 15 times on its way under.

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  12. #39
    Should Get Out More irie's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    ^^^ lol!

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    Should Get Out More Kneerly Down's Avatar
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    Default Re: Cranshaft key - car (Qashqai DCi)

    The belt went on my Rover 213 VDP (oh yes, I was dead posh back then) at Uni, on the autobahn in Germany and many ventiles were kaput.
    Thought my days of car ownership at Uni were over, but 3 weekends of working on the head had it back on the road and the car did another 60,000 miles after that...by which time it was mostly patches of fibreglass holding it together.

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    Default Re: Cranshaft key - car (Qashqai DCi)

    If there are cheap spare engines on eBay does it not make more sense just to swap the whole head? Presumably you can get an even cheaper head by itself anyway, but they're less common I'd guess.

  15. #42
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    Default Re: Cranshaft key - car (Qashqai DCi)

    Quote Originally Posted by Mr. Dazzle View Post
    If there are cheap spare engines on eBay does it not make more sense just to swap the whole head? Presumably you can get an even cheaper head by itself anyway, but they're less common I'd guess.
    I don't think I'd buy a second hand head by itself due to the likelihood of it having problems compared to a fully working engine.

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    Default Re: Cranshaft key - car (Qashqai DCi)

    Either way it's much easier than a complete engine out...

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