HELP! Need some advice on this one. I was coming home on the daily commute, sitting in slowish stop-start traffic, when for no apparent reason I could hear a little rattle coming from the engine at idle, seemingly in time with the exhaust burble at idle. Couldn't stop anywhere, so I carried on home which only took another 5 minutes or so and the engine was still running, but I kept the revs and throttle very gentle, and it did seem to quieten down from that initial noticeable rattle. Left the engine idling and went round to the engine bay to see the obvious cause of the rattling noise - the crankshaft pulley was wobbling around! Not wobbling as in moveable-by-hand but as in off tilted off to one side rather than perpendicular to the front of the engine, like when they do that spinning plate trick and it's not quite on properly.

To me that suggests only two things - either the nut is loose and it's not keeping it flat, or the crankshaft's bent. Neither of which sound like much fun to fix, but the former wouldn't be so bad I suppose...

Now for the cause. I checked the oil and there was hardly a trace of it on the dipstick. I cursed my idiocy as I had been planning to check all my fluids last weekend. Just to be sure it wasn't me reading it wrong, I topped it up and managed to put it about 3/4 litre of oil, so not a huge amount compared to the whole engine capacity which IIRC is about 4.5 litres, but certainly significant. I can see where it's gone as well - it's been blowing out of the crankcase breather along to my catch tank.

So, Subaru experts, what do you think? Is there anything I can check myself or would be a fairly easy local garage job like changing a crankshaft oil seal, or is this an engine out, new crank job?

 

Hi mate, have you tried a socket and bar on the crank nut? It may be the bolt/nut has just come loose..have you had a cambelt fitted recently?

 

Hello again! I can get a socket on there no problem, although the longest bar I have is a foot long torque wrench - don't know whether that is man enough for the job. How do I brace the pulley? Do I have to brace it at all? Do I just stick it in 5th gear or something?

I had the engine rebuilt about 3000 miles ago and it had a new belt then.

 

sounds like they must have left it loose then buddy.

 

It does sound like they never loctited the bolt and its come loose..you should be able to tighten it with the big bar you have..put the car in 1st gear with someone in the car with their foot on the brake..and tighten the hell out of it.

 

Please let that be it...
Any idea what torque it needs? Or should I just give it full beans?

 

Its helps if youve got a gagging tool to hold the pully while you tighten the nut, I had to make 1 to get my pully off/on when I did the cam belt, tried that putting the car in gear thing but there was too much backlash even with someone stamping the brake pedal to the floor while I turned it.

 

If you can give it full welly on the bar that will be fine..if you feel that its not tight enough you can remove the starter motor and lock up the ring gear against the bell housing with a big screwdriver, whilst someone tightens the bolt on the crank.

 

Having not done this before, it's all new to me. I've just been out with a 22mm ring spanner and that seems to go on OK (well it's a 7/8 actually but used it just to check) and the nut was very loose. Now the problem is I'm not sure what's in there while I'm tightening it all up, so a bit of an idiot's guide would be handy.

Does the pulley wheel need lining up in any particular way with the degree markings? Presumably it does, otherwise the cams will be mistimed? And once the wheel is tightened down onto the end of the crankshaft, it's basically turning the entire engine over unless something's done to keep it still e.g. holding the ring gear still through the starter hole or putting the car in gear and foot on the brake?

 

Just found a detailed diagram and it seems like I should be OK to fiddle about with it because none of the toothed pulleys can move independently as long as the cambelt's on. And what I'm looking at is just the auxiliary belt, running off the very end of the crankshaft.

 

stick the handbrake on tight, stick it in 5th.. remove the drive belt(s) from alternator and ps and aircon (if fitted).

remove the bolt and the pulley and inspect the pulley, the bolt and the crank end. If all okay then do it up tight (car in 5th with handbrake on should do it)
You'll need more than a foot long bar though unless you have arms like Arnie cannot remember the torque off the top of my head.. if you have some thread lock then I'd use it as it has come undone once.

3/4 oil down is nothing imho obviously not good but doubt you will have done any damage.. unless doing a track day etc.. where high G might have more chance of moving the oil away from the pick up.

Simon

 

Perfect answer Simon, nice one. I tightened it up last night with just a socket and ratchet arm - just to get me to work and back really. Looking at my torque wrench (which fouls on the radiator fan shrouding), it's actually more like 2 foot long and I found somewhere that the nut needs to be 100Nm, which is easy enough. Just got back from Halfords with some thread lock so I'll give it a go tonight.

Cheers for the reassurance about the oil!

 

The crank pulley bolt on the WRX came loose twice after replacing the cam belt, had to tighten it up a little over book spec and use pleany of thread lock.

 

sounds like a normal torque wrench so should be easy to get 100NM on it.

I normally remove the rad to gain access but am doing the cambelt at the time or refitting engine so need the access space. Hopefully you can get enough movement on it to do it up.. if not might have to remove the rad.. wouldn't try removing the fan shroud as it is most likely to sheer the 10mm bolts that hold it to the rad.

Simon