Opinions Requested

engines
noises

#1

Just purchased a 2008 Subaru Impreza Outback Sport with <60K miles for my son. The car is in great shape (body/interior) EXCEPT it probably needs a “new”/rebuilt engine. It started making a tap-tap-tap noise and the mechanic that looked at it said it was an internal engine noise; that they would not tear apart the engine to determine the cause, but install a rebuilt engine (at $5-6K). Advice?


#2

Get a second then a third opinion and never darken the doorway of the original “mechanic” again. He sounds like a scam artist.


#3

Concur with @missileman.

If you have a video camera (or a smart phone) try to get a recording of the noise and make it available to us. “Tap tap tap” can cover an awful lot of conditions. Some are very expensive to fix. Some are free to fix.


#4

You can count this as a third vote for avoiding that scam artist who is masquerading as a mechanic.

The noise could simply be piston slap–which is essentially benign.
Or, it could indicate a need to adjust the valve lash, which is something that should not be ignored.
Or, it could be a host of other issues, some of which are…ominous.

Only a competent mechanic who is interesting in opening things up for a look-see can tell you for sure.

If you use the Mechanics Files link at the top of this page, you can use a searchable database that will yield names & addresses of recommended mechanics in your zip code.


#5

Taps, rattles, and knocks can be subjective in nature so it’s difficult to guess at what the problem is.
Assuming this is not related to lack of oil or abusive driving and seeing as how it is described a tapping noise it could be that this is caused by loose valve lash.

Inspection and adjustment of valve lash as necessary is a normal maintenance procedure and is nothing to worry about UNLESS it is neglected and allowed to continue.

Playing devils’ advocate for a moment, it could be that if this problem does not sound like a loose valve lifter then anything over and above that will involve an engine teardown and the cost of a teardown alone could be a bit pricy.

You might consider another opinion or two as to whether this is a valve lash issue or something more ornerous such as a rod bearing or piston slap.
Rod bearing noise usually comes across as a solid rap sound often worse with a load applied, main bearings a deep subtle thump, piston slap rattling is usually not exactly rhythmic, and loose lifters come across as a kind of tinny, rhythmic tapping.