I have a co-worker that has a 2.2 Legacy 1995 AWD. Her "new boyfriend" said he heard a knock in her car. (It has 71K) I think he hates Subarus!

 

At any rate, she asked me to listen to it. I compared it to 2 of my EJ engines and it sounds identical, except she gets a slight knock/tap at low idle. No noise above idle, under load, deceleration, or acceleration. If you rev the engine up and then let it settle back to idle it takes a few seconds for the tap to start again. The tap is very faint, but noticeable. Does this just sound like a lifter? She had the timing belt, seals and h20 pump done 4 months ago. Nothing done to the oilpump however. There are no performance issues with driving and the car has been maintained VERY well! (mobil 1 since new)

 

I told her it's no biggie. Every engine sounds a bit different.

 

Your Thoughts??

 

Thanks, Todd

The lash adjuster is probably just sticking a little...nothing to worry about...it'll probably free itself up....pretty easy to check once you have the valve cover off.

Long screwdriver stethescope trick time. Isolate the sound to a side, cyl, or part of the block. Does this one have the adjustable valve lifters? Some people dont believe me but there are some that do.

Guys, I think this has hydro -lifters. I guess one might not be pumping up?

 

Todd

Guys, I think this has hydro -lifters. I guess one might not be pumping up?

 

Todd

 

if it has HLA's, then yup they can make noise. sometimes a grade thicker or thinner oil will help, though i consider that a band-aid more or less. or try some sea foam added to the oil. this can clean the HLA if it's build up related.

 

oil pump would have been a good maintenance item with all that timing belt, water pump stuff too. it has seals and screws on the backing plate that come loose. not saying that's the cause but good to take care of "while you're in there".

 

and the guy saying engine knock is probably wrong. is it me or does every diagnosis from people that know nothing about cars involve either "the catalytic converter is clogged" or "it's like it's not getting any fuel so it's the fuel pump".

Funny, it doesn't do it from cold, only after it warms a bit. Happens only below 800rpm.

try a little heavier weight oil if she's using the really thin snyth's now.

if it's is an HLA engine change the oil often (relatively speaking of course).

Yes, she has synthetic 10 30 I think.

that should be fine, i was thinking she might be running that really light stuff.

Todd, the possibility exists that whomever did the T-belt replacement did not tension the belt properly

and it is "flopping" around at idle.

 

As the RPM build the centrifugal force keeps it from flopping

 

I like the mechanics stethoscope idea Shawn has,

 

if it is a tension problem

it has the potential for skipping a tooth and causing some drivability issues.

How would one adjust the tension? Once you pull the pin on the adjuster, it's automatic. It presses against the tension pulley and pushes the belt down.

 

Slapping belt make sense though.

bump on the belt tension

Would not be the first time a so called specialist

forgot to relase the tensioner

 

fresh belt was tight and has loosened up some

when warm it has enough slack to hit the belt cover

??

 

stethescope can be a very good friend

You can use about 5 feet of fuel hose to pinpoint noises better than using a screwstick. Buy the bulk stuff so it isn't coiled up tight.

TC is right on

 

but

 

I find your typical garden hose fits

my elephant sized ear better. LOL

 

Placing a dowl or other cirular object in the

working end will provive a means for pinpointing

Have a listen to this:

 

http://www.geocities.com/vik2r/Sube/mp3/warmstart.mp3

 

 

It's my previous car, a 1990 Legacy 2.2 with the same engine as the 95. It's equipped with hydraulic valve lifters, just like the one you are talking about.

 

I know that recording doesn't have the engine idling for too long, but you can hear a slighty rattle in there somewhere. At the time of the recording the engine had 120k miles. Car is still running with 200k miles on the clock :-)

the later 2.5 engines were known to have

"piston slap" at idle

 

The piston skirt was to blame

 

could we be hearing this in both examples

 

There was reportedly no cause for concern

That recording kinda sounds like it. Her's is not quite as noticeable. She had an oil change and went to 10 w 40 from 10 w 30 and she reported it has all but stopped. Hmm....I think it's a sticky lifter now.

 

Thanks all for your input. You are all great!!