Short nose crank...telltale signs? *HELP NEEDED*

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deez
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Short nose crank...telltale signs? *HELP NEEDED*

Postby deez » Tue Jan 30, 2007 4:31 pm

What are the telltale signs of a short nose crank engine that is about to die? Anything to help me identify whether I'm experiencing this problem....many thanks guys :)
Last edited by deez on Mon Feb 05, 2007 8:12 pm, edited 1 time in total.
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StanTheMan
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Postby StanTheMan » Tue Jan 30, 2007 4:45 pm

here we go.....
where is Boagsy.
he is the expert.

Hope its not though :cry:

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Re:

Postby Boags » Tue Jan 30, 2007 5:04 pm

StanTheMan wrote:here we go.....
where is Boagsy.


:oops:

Power loss. It's not a stumbling coughing powerloss - that means you are out of petrol. :lol:

The timing starts slipping, so you lose torque and it feels sluggish and like the handbrake is on when down low. Get a timing light on it, if it is what you have set it at still, then you don't have a worry just yet.

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Postby Juffa » Tue Jan 30, 2007 5:10 pm

Plenty of info on the big forum

http://www.miata.net/garage/crankshaft.html

Hope it's not the real thing

J
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Postby kitkat » Tue Jan 30, 2007 5:31 pm

take off up a steep incline... well not to steep. If she struggles to get up and going then get a bit worried. It will struggle noticebly between 1000 - 2500rpms.

Major sympton in hesitation to get off the line (accelerating froma stand still).

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Postby Matty » Tue Jan 30, 2007 5:46 pm

I found it was largely a lack of torque, but the top end was still relatively good so it felt quite peaky (a function of the retarded cam timing).

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Postby Sheck » Tue Jan 30, 2007 9:01 pm

What matty said, also check that your crank bolt is still tight. When i caught mine it was lose and the key was quite damaged but the crank was still ok (tiny bit of damage). The loctite fix works really well.

If you havent changed the timing belt it should be ok, it only gives way when you dont replace the crank bolt (it stretches and is unable to hold the torque - so it losens and damage occurs). It'd also be a good idea to change the 4 bolts holding the crank pulley to the timing sprocket - this is one annoying failure that i dont want to go through again!!

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Postby JSE » Tue Jan 30, 2007 9:08 pm

I had the short nose crank problem....in my experience the three most major telltale signs are...

1. loss of torque (under 4K rpm it will have absolutely nothing)
2. above 6k rpm the engine will sound like its about to blow, violent shaking my be felt
3. screeching noises when turning corners or turning the steering wheel (due to the pulley and belt not matching up)

Those where the signs in my case...pop your hood open and have a look to see if there is a bit of a wobble. Mine wobbled like crazy just at idle and was just about to break just before i replaced the engine. Now my engine bay is full of Mr_Q goodness :mrgreen:
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Postby deez » Tue Jan 30, 2007 10:00 pm

Thanks for all the feedback guys. Will go through and try and diagnose each one of your suggestions on the weekend :)
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Postby deez » Sun Feb 04, 2007 7:29 pm

Hey guys,

I had a look just then at the crank at idle. It spins freely however there is a slight bit of wobble (ie not spinning to an absolute true line). What do you guys make of that?

I've also noticed the car do some strange things recently. On occassions when I'm accelerating, just after I shift up a gear the car seems to hesitate and doesnt respond to throttle for a split second. Then it seems to suddenly wake up and be fine again. It happens occasionally, but seems to happen mostly after shifting up to 2nd, or after shifting up to 3rd. It feels as if for a split second, I was on the brake while trying to give it gas.

Any thoughts? :? Are these telltale signs? :shock:
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Postby suzi » Sun Mar 04, 2007 1:19 pm

Hi guys,
Met someone at a party last night who has this problem. Apparently it took 2 mechanics to diagnose & the second mechanic suggested she sell the car as it is too expensive & too much trouble to fix?
She has had the car since 89? (said it was on the first load over?) anyway I would hate to see someone sell a car she otherwise enjoys just because it's too hard to fix?

I spoke to her about the runs etc we go on & she would love to join in but has no trust in the car at the moment....anyway point of this post - anyone know a mechanic on the Gold Coast to refer her to?

Kim
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Postby JSE » Sun Mar 04, 2007 1:25 pm

Deez...easy way to find out. If you are really unsure take your car to Daniel from Mania. He will pop the bonnet and tell you in about 2 minutes (thats what he did for me). If your nose is busted you got 3 options and all are fairly costly.

1. Replace the crank and all thats needed ($1000+)
2. Replace the engine with a 1.6 long nose ($1600 installed - my choice)
3. Replace the engine with a 1.8 ($2400+)

Hope this helps. Hope you arn't another victim :(
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Postby StanTheMan » Sun Mar 04, 2007 5:27 pm

or do the locktite fix.... not exr-treemly expensive but very labour intensive . & prolly not really an option for a worhop like Mania. This is only an option if you are prpared to do the work yourself.

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Postby JSE » Sun Mar 04, 2007 10:19 pm

yeh or the loktite fix, forgot about that one. 'stan you are the man'
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Re:

Postby Boags » Mon Mar 05, 2007 9:27 am

JSE wrote:Deez...easy way to find out. If you are really unsure take your car to Daniel from Mania. He will pop the bonnet and tell you in about 2 minutes (thats what he did for me). If your nose is busted you got 3 options and all are fairly costly.

1. Replace the crank and all thats needed ($1000+)
2. Replace the engine with a 1.6 long nose ($1600 installed - my choice)
3. Replace the engine with a 1.8 ($2400+)

Hope this helps. Hope you arn't another victim :(


None of those prices seem right to me...

I would have thought a re-built 1.6 would owe you a lot more than $1000.

I have been offered a long nose 1.6 for $500 (by a very similar outfit to Mania... So it's not a one off price). You would then need to add gaskets and what not.

I have been offered a vvt 1.8 for $1500 (from the same place). Again, add gaskets.

As an enthusiast, you have many many workers at your fingertips, right here. A few snags and a carton of beer saw Red5 with an installed long nose 1.6. No need to pay a workshop, no matter how inept you are.

I appreciate some people don't have the liberty of waiting for a dodgy day. YMMV, but I'd say you'd get away with a 1.6L engine swap for less than $1K.

Suzi, let your friend know that she needs to have a "dodgy day"... 8)

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