Started the engine on my 93 WRX this morning, and heard a very loud 'clicking' noise. I had checked the oil level at the weekend, and was towards the bottom of the dipstick (just above the 'L' mark), so added a little more to see if would make any difference....no.
Drove very gingerly to work, keeping revs as low as possible, and it has now quietened down to about the same level of noise as the injectors.
No noise on the Knocklink (although didn't get near 3K rpm!), and no evidence of smoke out the exhaust.
Only mod is full decat.

I suspect it's something to do with the cam...can anyone offer any advise on what it could be, and whether it's likely to get worse?

Dave D, m Sounds like a set of rattly hydraulic lifters is the best bet from your description. Low oil level wouldn't have helped either.

Try flushing them out to clean them up by adding up to a litre of automatic Trannsmission oil in place of the same amount of engine oil. DO NOT overfill it's as bad as underfill on a Subaru, Run it for about 300 miles and then drain and refill with a good quality synthetic oil of no less than 10W/40 viscosity.

with luck you'll be off and running again.

David API Engines

David,

thanks for the prompt reply! I was planning to do an oil change sometime in the next week, so I'll add some auto-transmission fluid along with the regular stuff.
I assume the transmission fluid has different properties to normal engine oil? I also guess I shouldn't drive to hard with the hybrid mix?!

Arrrrgghhhhhhh!!

Don't put anything like that in a Turbo car!!!

ARRRGGGGHHH you are scarying me!

Seriously just change the oil .. try Motul 300V 15W150 Competition from say www.demon-tweaks.com and fit a prefilled Subaru filter..

If you are not sure on noise pop into dealer and get it checked..
doesn't cost anything for a check!

JGM

With 93 WRX are sure, the dealer will laugh you off the forecourt, "don't touch grey import, ha ha ha"

Going to the wrong dealer then..

He'll laugh even more when you explain you put auto trans oil in it.. lol..

Try connecting green connectors under dash.. (maintenance mode) and with immobiliser off turn ignition on (not engine) and all the relays click.. and fans runs etc.. see if the same clicking is heard.. if so then it is a relay etc..

JGM :)

OK,

thanks for the extra replies....haven't bought any transmission fluid yet, so probably won't bother! Car was much quieter on the way back from work yesterday, so not sure what the cause was. :confused: *
Definitely sounded like a tappety noise (increasing in frequency with revs), but no CEL, or oil pressure light to indicate any probs.
I'll do an oil change and see what happens (hopefully nothing!).

* actually, on Sunday I started the car, drove it 2 car lengths into the garage, and switched off. Normally I would let the engine idle for 30 secs or so, but for some reason didn't bother on this occasion (never thought it would really cause a problem!).

Ye olde piston slap? Not sure which models it stands out in particular on, but this moght be one?
Piston slap is noisy when the engine's cold, and then goes when hot. A thicker oil (well, the right consistency :)) such as the Motul 300 (15/50) should reduce it & sometimes even seems to remove it. Not the slapping - which in itself isn't anything to worry about - but keeps it quiet.
That is if it's piston slap at all...:)

JGM and others,

UK Subaru dealers sell, or used to sell, a cleaner for hydraulic tappets that comes from Australia called ' Superoo ' geddit?? and when analysed turns out to be ATF.

We have been using this ATF trick for years and it works fine without any detriment to ANY engine that we've ever treated !!

Do you seriously think I would offer advice such as l did as an experiment !!

David API Engines

Thanks for all your comments.

The noise appears to have been a one-off instance, and I can only think that starting the engine and shutting it off almost immediatelly was the cause (won't be doing that again!). Perhaps this created some sort of air lock?

I have bought some 15W/50 oil to flush the system, and will see if this makes any difference.......