I have about 200k on my forester. Friday when I was leaving work I cranked it up and it made a loud knocking sort of sound. I drove it home (about 15 miles) and on the way the sound lessened. It was louder when the car was idling but she made it home ok. Next day, started the car and it happened again. Not more than 50 feet up the road we stopped at a stop sign and it sounded like a semi was starting up around the corner. Much to my dismay it was not a semi but my own car. Engine shut off. We pushed it back to the house and tried to check it out the next day. This time, we started it, didn’t go anywhere, and within 30 seconds it turned off. Same loud knocking sort of sound. The confusing part is that all of this happened within two days. There was no gentle sound leading up to it for a few weeks or even a few days. Knocked on Friday, shut off on Saturday. What could be going on?
Pull the plugs and check their condition. Is the check engine light on? Subarus tend to blow head gaskets.
Plugs were changed in the spring of 2013, and the check engine light hasn’t come on… It’s baffling.
The reason I said pull the plugs was to assertain their condition, black, white, wet, normal.http://www.cyclepedia.com/spark-plug-troubleshooting/
Have you checked the oil?
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This!
When was the last time that the oil level was checked?
Te oil was checked Today…it’s fine. Checked twice. We’ll check the plugs again tomorrow.
It might be time to have an oil pressure check performed even if the oil pressure lamp is not being illuminated. At 200k miles I could think of a number of possibilities.
What year and engine? Does it appear to run fine other than the noise?
2002 2.5. It runs fine otherwise. No decline in gas mileage, transmission shifts smoothly. Past couple of weeks it developed a clunk going into reverse, we assume it’s a u-joint.
To be honest, I can say that I don’t have a clue although there are a number of suspects. It’s near impossible to be precise on a noise diagnosis without hearing it.
I’ve got a lot of possibilities in mind but hate to throw them all out there as many are major and I hate to scare you at this point.
Just a suggestion, but can you remove the accessory belt on the front of the engine? If so you might consider doing that, start the engine for a few seconds, and note if the noise goes away. If it does disappear there is the possibility of a bad harmonic balancer which if caught early can often be repaired without too much pain.
Any history in the recent past of having the timing belt changed or anything like that?
Would the harmonic balancer cause the car to shut off? Do Subarus even have a harmonic balancer?
About 4 months ago, we had tested the alternator, I can’t remember why at this point, and had to remove it which I believe made us remove the timing belt. That was put back together without an issue though. The timing belt is in good shape.
You removed the serpentine belt. You can have the alternator and battery checked at Advance or Autozone for free. They can hook up their computer and check the charging system in seconds.
Is there a crank position sensor next to the harmonic balancer (the crankshaft-driven pulley)? Maybe it is dislodged.
This is what it sounds like. Yesterday the clanking sound was much more prevalent. You can hear it somewhere near the end of the video. The squeal is new. I shut it off at the end–it didn’t turn itself off this time.
Checked the spark plugs. Looked pretty normal. There was a little bit of oil on a couple of them but that’s been consistent with the last few years. Went on to change the oil and noticed that the last oil used was 10w30, we went back to 5w30. All the metallic knocking sound disappeared after 30 seconds of idling, but high pitched belt-like squeal is still there. Driving now, we’ll see how it goes.
I’d pull off the serpentine belt and try turning each pully by hand. It sounds like you have a bad bearing in one of the components that run off the serpentine belt. If one pully feels hard to turn or wobbles replace that component and get a new serpentine belt.
Yosemite
Will turning the pullies mess with the timing at all?
“Will turning the pullies mess with the timing at all?”
Not at all. That squeal sure sounds like a pulley binding up. The other noises are cringe-inducing.
We took it to the shop and they ended up replacing the water pump and timing belt. Picture on the left is what the part should look like, the right is what it did look like.
The bearing on that gear is flat gone. You’re lucky that it didn’t scatter itself all over the place before the repair.
That’s due to aged grease which has gone south and a dry bearing. The bluish tinge is heat due to lack of grease.
Thanks for posting back with the results.