How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt
Matt, Engineer
Category: Subaru
Satisfied Customers: 20577
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
12772297
Type Your Subaru Question Here...
Matt is online now
A new question is answered every 9 seconds

I have a 2010 outback 2.5 limited with 59,000. About 1 or 2

Customer Question

I have a 2010 outback 2.5 limited with 59,000.
About 1 or 2 times a month when I start the car after it has been sitting overnight it starts with a loud clatter that stops in a second or less. It sounds like there is no oil in the valve area and once the oil hits that area the clatter immediately stops. I am using 5 / 30 recommended oils and have switched to synthetic 5/30.
Do you have any suggestions as to what the problem is and how to fix it?
Submitted: 10 months ago.
Category: Subaru
Expert:  Matt replied 10 months ago.

Hello

I'd first try removing the auxiliary drive belt and turning every pulley and ancillary ( power steering pump , alternator etc) by hand. All should turn easily (with the exception of the AC pump) with no grittyness or wobbly pulleys- If you do find a sticky pump / alternator then it should be replaced or repaired

If the engine is stone cold you can briefly run it with no belts to see if the noise changes or has gone away, this will help show if an ancillary is the issue

Another possibility is the variable valve timing system as this does rely on oil pressure to correctly synchronise your vvti pulley on the end of the camshaft. If the valve has become blocked up then its possible the pulley is rattling about and producing the noise.

if you've got a top-end rattle or regular ticking that increases in tempo with increasing rpm then yes I'd agree it could be a sticking valve lifter, as these use a small hydraulic piston to take up the valve clearances and what can happen is the small oil ways that feed the piston chamber can get clogged up

If you haven't already then I'd try an oil flush treatment complete with a new filter and fresh oil

Expert:  Matt replied 10 months ago.

Hi

do you still need help?

Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you