engine knock? appreciate your thoughts

ghall · #1 08-24-2020, 01:37 PM

Hello, I'm the original owner of a 1992 Subaru SVX LS-L, currently with
120,000 Km. For the past 10 or 15 years, I've been leaving it parked in my
garage over the winter and take it out for runs in the spring/summer for no
more than a total of about 100 Km. This year, my SVX has developed an
engine knock. I'm unable to directly attach a few short video recordings I
took of the knocking due to web site restrictions. Instead, I uploaded
them to my OneDrive and include the link below. I'm hoping that someone,
based on their experience, might be able to suggest what they think the
source of the knock might be. Any and all thoughts are welcome. Here's a
few more details:
- knock is the same whether engine is warm or cold
- rate of knocking increases/decreases with engine RPM
- engine performance is fine; idling smooth
- I tried some SeaFoam in the oil -- didn't seem to make any difference
- since then, I changed the oil with full synthetic 5W40 weight

Here's the link to my recordings:
https://1drv.ms/u/s!AtnY_qTU7zVviONS...Ny7Mg?e=IelgT0

Thanks in advance for your thoughts,
Gary

Stevebsy · #2 08-24-2020, 02:17 PM

How long have you had it running?
I seem to remember mine doing similar things, so I left it idling in the driveway for an hour or two and it eventually got better.

If you live in a relatively warm area, you can use 20w50 per the owners manual as long as the temperature is above some # I can't recall, maybe 30 F?

Your issue is not super uncommon, might want to dig around in the search. Good luck!

ghall · #3 08-26-2020, 12:06 PM

Well color me shocked. I took your advice and let my SVX sit idling for more than hour. To be honest, I was doubtful that it would make a difference since I had already tried SeaFoam. But, after about an hour, the knock gradually dissipated and eventually disappeared. I was surprised, but elated. My guess is that it was a stuck lifter that gradually "unstuck". Many thanks for your suggestion!!
Regards,
Gary

LarryIII · #4 08-26-2020, 06:44 PM

Gary,
You might also try using a good synthetic oil such as Mobil 1 in your SVX. I have converted all of my cars to synth. oil and change it every 5000 miles or 6 mos. ( which ever comes first). I've never had internal engine problems. It's not cheap. But I look at it as good insurance. Good Luck & Stay Safe.

ghall · #5 08-27-2020, 08:08 AM

Quote:

Originally Posted by LarryIII

Gary,
You might also try using a good synthetic oil such as Mobil 1 in your SVX. I have converted all of my cars to synth. oil and change it every 5000 miles or 6 mos. ( which ever comes first). I've never had internal engine problems. It's not cheap. But I look at it as good insurance. Good Luck & Stay Safe.

Thanks. It's Canadian Tire Motomaster 5W40 full synthetic oil in it now, but next oil change I'll go with the more expensive Mobil 1. Do you recommend an oil additive to help keep lifters from getting gummed up? Or stay away from that?
Gary

LarryIII · #6 08-27-2020, 08:14 AM

I don't use any additives. I never heard of the oil that you're using. Do you know who manufactures it?

SVX_MY_BABY · #7 08-27-2020, 10:57 AM

Quote:

Originally Posted by ghall

Thanks. It's Canadian Tire Motomaster 5W40 full synthetic oil in it now, but next oil change I'll go with the more expensive Mobil 1. Do you recommend an oil additive to help keep lifters from getting gummed up? Or stay away from that?
Gary

I believe that's been discontinued and replaced by "OEM" brand at Cdn Tire.

My understanding is that if the oil meets SAE spec for the engine that's all you need. Branding doesn't matter much.

Stevebsy · #8 08-26-2020, 07:15 PM

Quote:

Originally Posted by ghall

Well color me shocked. I took your advice and let my SVX sit idling for more than hour. To be honest, I was doubtful that it would make a difference since I had already tried SeaFoam. But, after about an hour, the knock gradually dissipated and eventually disappeared. I was surprised, but elated. My guess is that it was a stuck lifter that gradually "unstuck". Many thanks for your suggestion!!
Regards,
Gary

Ah nice! Glad to hear it.

I'm about to start mine up tomorrow for the first time in about 18 months after finally getting my 5MT swap done. I pulled and resealed the engine during this project too, so it's not been run for a long time...