Pulley wobble and oil leak - 2000 1.8S

Technical Area Engine, Transmission, Exhaust etc
2

 Hi,

Sorry if this has been asked before, but I have just noticed a problem and i am really worried it might be serious. Basically, the car has had a oil leak for a while which I havent been able to place - its at the front of the engine quite low down. I have just been topping the oil up until i take it to a garage.  Today when i opened the bonnet i noticed that there was a quite but strange noise coming from the engine, and the crankshaft pulley was wobbling slightly - having read around i have seen that earlier MX5s suffered from pulley wobble, but i cant find anything about later (mk2) models.

Can anyone tell me anything about pulley wobbles, and what i need to do next?

Thanks,

Chris

3

 it sounds like your keyway has worn , allowing your crank pulley to have play

it is usually a result of a timing belt change by someone who bodged it.

Best way to find out , is to take the crank pulley off completely and check the keyway for wear  / play

 

Do a search for the loctite fix

4

 I would also have a look first to see if there is any damage?You maybe lucky and got it just in time,but it does sound like it could the woodruff key and crank shaft to be honest,as for the locktite fix you would be lucky to get 12 months from it after all the time spent and money,if it does turn out to be the worst,just get hold of a low milage s/hand engine , if bossible, try and hear it running.

Kind regards

5

Hi

I thought this crank pulley problem was more to do with the early short nose 1600 engines?  The early Mk2 1800’s however could suffer from thrust bearing problems and if this is the case it can result in the crank oscillating back and forth giving the appearance of a loose pulley.  Best cure may still be the same, ie another engine.

Alan

6

http://www.mx5oc.co.uk/forum/forums/t/356.aspxWink

7

 Right, now I (and my mechanic friend) are very confused! Today we took off the pulley to try and see if it was bent or if there was any damage behind it, and there doesnt seem to be anything wrong.

We discovered that the oil leak is coming from the crank area (behind the pulley), but the pulley itself seemed straight, and the woodruff key (is that what that little bit of metal that sticks out) looks in one piece.

My mechanic friend could only think that the actual crank is bent, which would cause the oil seal to break hence the oil leak, and the pulley to wobble. He doesnt usually work on MX5’s so he wasnt 100% sure.

Does this sound right, that the actual crank is bent - and if so how on earth would it have bent in the first place? I assume its time to trade in the car and go and buy a new one quick!

8

Today i took the car apart again and took some photos:

http://s838.photobucket.com/albums/zz305/Chrisctk/MX5/

What do you think - does it look like the keyway is the problem, and if so does it look repairable?

What should my next steps be - as previously mentioned i am not very mechanical (I managed to get the pulley off today after remembering how my mechanic friend did it yesterday), so an ‘idiots guide’ to whatever I have to do next would be great! Also, the oil leak I am suffering does seem to be around the crank - so would I be able to fix that at the same time (again, an idiots guide is a bonus)?

Thanks again everyone!! 

9

 Forget the locktite fix,i have known of owners which have had it welded on which does work well,i would  personally take it apart to have a good look at what you have and have an engineering Co make up a new key to fit the new Grove,sort out the leak,put a new water pump,cam belt on etc,so there will be no need for a long time to go back any where near again