Last post on Aug 25, 2012 at 1:58 PM
You are in the Subaru Forester Maintenance & Repair
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Subaru Forester, Engine, Wagon
#400 of 439 knock like sound on the start
May 30, 2011 (9:17 pm)
hi guys. this is my first time to use z forum so i hope z i do well. anyways, i have a 2010 Forester with 15000miles and every morning or even after parking for a couple of hours i hear a knock like sound coming from the engine, does anybody have an idea about that? and one more question, i asked the dealer what kind of oil they use and they told me they r using a semi-synthetic blend (as i remembered), so if i changed to the synthetic will this be ok?
#401 of 439 Re: knock like sound on the start [amkmeco90]
Jun 01, 2011 (7:54 am)
if it is a 1-2 second slap-slap-slap and then silent, that would be the infamous piston slap. Mine was fine for 80,000 miles, with only a once a year piston slap incident when it sat for several days and then a cold morning start.
Now, at 140k, if it sits for 4+ hours and the engine cools off, it will slap everytime. I use exclusively 10w-30 synthetic.
Supposedly, this is "factory" and "fine" although many complaints have been voiced over the years.
#402 of 439 Re: knock like sound on the start [once_for_all]
Jun 01, 2011 (9:55 am)
Thank u for ur answer, but the sound is just a knock at the start of moving then nothing not a slap slap. And one more question, f I want to change the kind of engine oil will this be ok? I know z they r using semisynthetic blend as I recall.
#403 of 439 Re: knock like sound on the start [amkmeco90]
Jun 01, 2011 (11:20 am)
Changing the engine oil will be no problem at all. What is your oil level? Sometimes they will have lifter noise for a moment or two at start-up, especially if the oil level is low at all.
#404 of 439 Re: 2011 Subaru Forester vs 2010 Subuaru Forester? [saedave]
Jun 05, 2011 (7:46 am)
Do u mean z 2010 forester owners will experience the head gasket failure? And does the way of driving will affect this?
#405 of 439 Re: 2011 Subaru Forester vs 2010 Subuaru Forester? [amkmeco90]
Jun 05, 2011 (9:52 am)
Most Foresters will NOT have the failure, but a few will if they are like other years using the same engine. Head gasket problems have also been in early years of Toyota Celicas and other makes and models. Toyota fours do not have the problem today; they fixed it. The new Subaru engine has been improved to greatly reduce the probability of such a failure. Volkswagen had head gasket and transmission gasket failures in their early VR6s; later ones seem to be fine. If the price difference were smaller, I would buy the 2011. The price difference you were quoted seems excessive.
#406 of 439 Re: 2011 Subaru Forester vs 2010 Subuaru Forester? [amkmeco90]
Jun 11, 2011 (9:48 am)
"Do u mean z 2010 forester owners will experience the head gasket failure? And does the way of driving will affect this?"
The way of driving has no effect. The 2010 engine is the least likely of all the old EJ engines to have a head gasket leak. It has a redesigned head gasket that only fits that year.
The new 2011 FB engine was redesigned to separate the cooling of the head from the rest of the engine. The head gasket between the block and the head was then no longer the weak point in the cooling system
#407 of 439 Sustained Piston slap at 83,000 miles
Oct 08, 2011 (12:11 pm)
The dealer dropped my Impreza Outback Sport off the hoist & totaled it. They want to replace it with a 2001 Forester. It has had 5 owners and 3 independent mechanics I took it to expressed considerable concern over hearing sustained piston slap (long after engine is warm). I told the dealer about this & they confirmed it does indeed have piston slap but assured me that they don't think it is a problem or will become bad enough to be a problem. This 2001 Forester has 83,000 miles on it now and I need it to last for another 100,000. Will the piston slap turn into a serious & expensive problem in that time? The dealer did not actually tear stuff apart to actually have a look at the pistons. Help, I do not know who to believe!
#408 of 439 Re: Sustained Piston slap at 83,000 miles [subydo]
Oct 10, 2011 (2:02 pm)
Five previous owners in 83,000 miles; that says quite a bit all by itself. Honestly, I would probably take the insurance payout on the Impreza and just put it toward a replacement car of your choice (new or used).
Even if the issue is "just" piston slap, the concern expressed by the mechanic and the dealer's own lack of credibility (after all, this is the same place that totaled your car in the first place!) means you likely will have more than a few headaches down the road.
#409 of 439 Re: Sustained Piston slap at 83,000 miles [xwesx]
Oct 11, 2011 (8:38 am)
I agree, 5 owners is a red flag. Most Foresters that age are on their 1st owner, maybe 2nd.