Subaru Piston Slap - Does using Shell Rotella help?
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- Опубліковано 8 вер 2024
- Testing on an early 2000s Subaru Forester with 250k km on the engine.
This engine clearly has piston slap.
One common suggestion online to address piston slap is to use Shell Rotella oil (preferably at a heavier weight, like 0w-40). Here we test that theory to see if it makes a difference (or not) in the cold-start piston slap sound.
Baseline piston tap recorded with Mobile 1 Synthetic 5w-30 in the engine at cold start.
Tested the next morning after having changed oil the previous day with Rotella T6 Synthetic 0w-40.
You be the judge if there's a difference in the sound pitch or volume of the piston slap.
2021 UPDATE: A little over 2 years and about 60k km later, this car still has the same piston slap, but is running just as well as it did when the video was made. Piston slap is just part of life on these older Subies. :)
It’s just a old Subaru thing. Live with it! My forester has been doing it forever.
In all fairness you went from a 5W oil to a 0W oil. That's why it was louder (to my ears) when you switched.Try the 5W40 or 5W30 Rotella instead, if that doesn't help go to 10W30.
Winter weight applies to the oil's properties at freezing temperature. It is not linear, nor do the 2 sets of numbers before and after the 'W' have any relationship to one another. That number, though lower, is significantly thicker than the 30 or 40 # after it. In other words, 0W40 will warm up faster, but the oil is still thicker than 5W30. The only thing the 1st number indicates is the lubricity at freezing temps, and it can only be compared to the 1st # on other oils. The 2nd # is the lubricity at operating temps. - "Up the Irons"
@@kaganhudayar630 I already know that and I was referring to cold weight of the oil (at 32 degrees) when I made my comment.
Try 5w and lucas oil instead these cars aren't like the ones in vicegrip garage i would be cautious even if it worked for a while with that rotella.
I have a 2003 outback limited sedan with only 38,400 miles and it slaps as well when cold out..I've owned many subarus and this is the first I've had with the slapping. Hoping it's not a major issue but will continue to monitor.. sold my 2016 sti because of reliability and hate worrying about my subarus..I never learn my lesson buying these things 🤣
I have an '05 outback and yes it too is noisy on cold startup!! Quiet as a mouse after it is warm... so, I think that this type of engine is inherently more prone to this type of noise because the pistons are moving on a horizontal plane.
Just keep the oil fresh and clean and just live with that little bit of cold noise.
Mines been that way for over 5 years and it reliably gets me to and from work every day!
That sir is the correct answer but 5w30 and some lucas oil would have been the better option but i haven't on mine and it's fine.
Normal for older subarus, use 10w40 and it helps.
Yes I plan to use 10w-40 on my Impreza, thank you.
rotella t6 5w40 actually made the piston slap louder on my wrx. it did significantly slow down my valve cover leak though.
My old 2.2L Chevy s10 slapped like that for years until it finally burned a valve and I rebuilt it. Damn thing still has a light clatter to it on deceleration even with fresh bore and new pistons 😂
10w 40 or try the 10w 50. On older higher mileage subs seems to always get the piston slap, its just the joys of a boxer engine lol even low mileage subs gets piston slap even worse on the wrx's and the sti's. I would recommend to get octine boosters for the gas tank and 10w 50 full synthetic engine oil and a HKS oil filter or use the OEM factory oil filters. You forgot to tell your viewers that piston slap is a problem and if left you risk damaging the block over time...
Google ref:
A piston slap can become a bigger problem over time. It steadily wears down your pistons and bores, leading to the premature death of your car. If you're planning on having your vehicle for a long while yet, you will want to fix this problem sooner rather than later.
All the Subie's I've done bore measures on with piston slap the bores are fine. It's just the skirts that are the blame, and usually just the top, so I don't see this as a long-term damage kind of issue (i.e., easy to replace pistons or 'flip' them on the pre-2006 engines if the As & Bs are symmetrical across the sides).
Ah, finally sense at the end of the video. Oil cannot reduce piston slap, there is space between the piston and cylinder, it is not magically filling up with oil. The idea of thinner oil to prevent cold ticking is for hydroulic lifters with narrow passages. Thicker oil could mask worn bearrings, but no remedy for slap. It does wear out the cylinder more quickly, so I would replace pistons if the car is still worth it.
Agreed, but even if you replace the pistons, the wear to the cylinder bore has been done, so likely new standard pistons would still be slappy. And getting a rebore to the next piston size up involves splitting the case, so probably never worth it given the engine will likely live another 100k+ km easily with the current level of piston slap (and this one is already 60% of the way there from when we recorded this video).
@@stephenhunt6253 In that case it is understandable. Then just drive it till it goes.
I run 20-50 in my hybrid subaru engine for piston slap, the manual stated you can use a 50wt oil.
Taping was louder. I’d use 5w-30 as recommended by Subaru.
I use 20-50 mobile 1 in my hybrid block build with worn 255 pistons and rehoning a worn bore. It slapped like hell with 5-30 in it and purs like a kitten with 20-50. 255 with sohc 251 heads at 20 psi. Brand doesn't matter.
That oil is SO THICK but the other parameters you're mentioning with worn bores and pistons justify it.
I, too, am curious about your oil pressure.
slap sounds louder on the rotella. Maybe try T6 5w-30?
T6 5w40 would work better.
I use to have really loud piston slap on my 02 wrx, i put in 10w30 and it really made a difference in my car.
Hey still have your 02 wrx? I noticed louder piston slap after changing unknown oil to ultra platinum 5w30, will def switch to 5w40 and try that out
Keep me updated . Xt 2.5 with piston slap
People are going to find out synthetic is not all it's cracked up to be.it's causing major engine damage in Fords coyote, Chevys LS, Chrysler's hemi. I quit using it years ago and my Caterpillar engine. I now use 15,40 rotella and Lucas oil stabilizer.I'm still a believer and a user in Castrol 20-50 in these small engines. Synthetic causes a lot of burnishing to camshafts and upper rocker arms. Also to be found that it does not allow piston rings to seat properly when installed in a rebuilt engine.
I agree that Synthetic hinders break-in of new rings, but I haven't had any issues with camshafts or rocker arms as a result of using synthetic (at least on a Subaru).
I have never had any of those issues in my vehicles. I've driven hundreds of thousand of miles on synthetic oil. And I have been using synthetic oil for almost 30 years now. The problems you attribute to synthetic oil are because of poor engine designs and just the plain low quality, gimmicky engines of today. It also can be attributed to the lead foots that drive those pseudo muscle cars they make today.
@@stephenhunt6253 I always broke new engines in on Dino and made the switch to synthetic with no problem in 30 years and hundreds of thousands of miles driven.
@@j.t.cooper2963 I hear ya. Except for piston-ring break-in, I plan to continue to use Synthetic in my own car.
Had a similar noise from the driver's side only with cold start then gone after 15 miles of driving.New timing belt and tentioner kit.It wasn't piston slap.It ended up a being a worn intake,exhaust rocker and shaft.
Replaced both with "good" used.Cold knocking is now gone.And yes, I do have a faint piston slap,but very faint.
So, it was a worn camshaft? What year/model?
@@stephenhunt6253 The camshaft looked fine.The rocker shaft had wear marks under the load side of the rockers at the oil feed ports.
@@stephenhunt6253 here's the link to the rockers.ua-cam.com/video/IENZOH1_K1s/v-deo.html
@@virgilmobile1 Interesting! Was this the 2.5 SOHC engine?
@@stephenhunt6253 Yes.New to me.2003 Forester 2.5 SOHC.172K miles.All original.Even the timing belt and tentioner.
Have you tried lucas oil stabilizer? Try putting a half quart in on your next oil change. I have been using it on my wife's vehicle and it's quieted the piston noise.
Will try that and video results!
@@stephenhunt6253 I’ve tried Lucas in my 05 OTB, Lucas seemed to accelerate oil consumption. And it’s too thick in the cold. I’m in Quebec, we get -35 mornings for weeks in a row, I stopped using Lucas all together.
I had slap noise on my 2006 4.0 V6 4runner. Put that exact same T6 in it and it didnt seem to help.. then we took it on a 800 mile road trip a couple days later.
When we arrived at out destination, THE SLAPPING had ceased!
Hasnt made any sound since. Not even cold start.
Interesting!
@@stephenhunt6253 yea I was shocked! I heard some fluids take some miles to see improvements.. Seemed like Piston#1's wrist pin was getting jammed in position when down or up stroking, causing my "slap". The SLAP never went away, it was always there after it warmed up!
I think the Rotella did it's magic when I got it flowing for hours on end at normal engine temps. I only shut off the engine once the entire 12 hours to get out to eat.. I gassed up running.
It may have stopped at ~400 miles.. think I recall a drivethru I went thru for a late lunch/snack lacked that awful "TICK" noise.
Thanks for this. My Subaru has terrible piston slap on cold weather startup. It's started to lose compression on one cylinder on cold startup now; it idles rough for about a minute. Runs fine when warmed up though.
I used to put "Motor Honey" in an oil guzzling Cadillac engine. It helped with oil consumption and made the engine quieter. I'm still hesitant to put a product like that (basically thick goo) in a modern engine, especially in the bitter cold weather.
I had a couple of heavy duty cold starts last winter. There were a couple of mornings where the temp was minus 20 to 25 degrees F. It took a long time to start and did it sound terrible idling. But ten minutes later it was ready to go. The piston slap got worse after that.
Piston slap won't cause any compression loss. That may be either worn rings or a valve issue. Did you do a wet compression test?
That's definitely not piston slap if you list compression
@@AndrewB23 It's been slapping for 70K miles without using oil. Now it's using oil.
@@stephenhunt6253 Then what causes piston slap if not a loose piston//sleeve or rings? :D
@@vihreelinja4743 Piston skirt wear.
Also having this issue, just started a couple days ago. More noise on acceleration, and climbing hills. Especially on cold start. I currently run 5w-20, was told to switch to 10w-30. Any help with knowing which weight to choose would be greatly appreciated. I replied on a comment, but meant to do it here. Too tired to re-type. Check in the replies for more info. Thanks so much, 😃
5L
Not sure if you got your answer, or if this is still relevant, but here's my $0.02
I have an 08 Outback with the 2.5L H4. It just picked up a cold clatter that's louder on acceleration and goes away when warmed up. 100% piston slap diagnosis.
I would say you could go up to a 10W-40, because the thicker oil will cling better when cold, which is when the slap is trying its hardest to damage the piston/cylinder wall. If you're also losing oil (burning/leaking) the thicker oil at operating temperature should help to reduce the loss.
My car consumes 1 qt every 1,500 miles, but that was with 2 hours of commuting at 55 mph every day. Not sure how it's going to change now that I have about 40 total minutes of commuting at about 35 mph average.
5w- 40 if you live in a cold place or 10w 50 if your in a hot place but 5w- 20 is defo a NO GO!! Poor engine 😐😢
Use diesel oil works great for me
Try Extra Thick ET40/70W or CV boot grease to stop that slappedy slap
LOL!!
Stupid
The heavier oil its worst for your engine less efficient and bad when is super cold.
Pretty much every Subaru engine slaps.
Yep, as they say, "A Subaru that doesn't tick, doesn't run". :D
Only true way to get rid of piston slap is rebuild the short block. And better pistons
yep!
I think a better size postpn would help more than quality.
Use straight 30 wt
Has anyone tried a mono grade 40 oil?
Why would putting a thinner oil at cold startup (0w vs 5w) help piston slap? You’d want 10w instead.
Hmm, 0w40 is thicker than 5w30. But anyway, that was just the suggestion on some of the Subaru forums (not sure where the idea originated) that I wanted to test.
@@stephenhunt6253
Just recently got this ticking, bad in the mornings upon start up. Also revs high for first 30-40 seconds after starting before it dies down to a normal idle. Was told by someone it's a lifter or rod, but I'm unsure. He told me to switch oil from my 5w-20 to 10w-30. Not sure if that's a good idea. He said it's a thicker oil, and it will help lubricate better. Any suggestions? I have a 2013 Kia Forte Ex, 2.0 litre With 111,200 miles. I recently had a used motor installed, as mine blew a head gasket at 105,000 and now this motor has given me nothing but problems and it had 84,000 miles on it according to the wrecking yard I bought it from. Going on a massive 3,000 mile trip, and I don't want to brake down. If switching oil can help, please let me know, which is better. Thanks
@@joleneshipp3946 Are you able to isolate the location of the ticking? Stethoscope or just a long screwdriver to the ear? If it’s in the heads, it might be your valve clearances. If it’s coming from the bottom end, could be worse. 84k seems a bit low to have piston slap (or any bottom end) issues, unless the engine was abused (which you’ll have no way of knowing, of course).
@@stephenhunt6253 yes, it does sound too sided. Today, I added 1/2 quart of 5w-20 and the ticking did get softer, or lightened a bit. I'm just not sure which oil to put in with the oil change coming up next week. As I stated, I'm going back to Georgia in a couple days, and don't want to get stranded. So if going to synthetic, or a different weight, how do I choose?
Top sided. Not rod related, as it sounds almost like it's near my fuel injectors up top
Is it the high pitch sound or something different?
Nah, the high-pitch sound is probably the power-steering pump, they're always noisy as they get older in these.
Shoulda use super tech
Cigueñal
Nope.
That's not piston slap.
Replace your Belt Tensioner
And it will be gone!
Belt tensioner was a brand new Aisin. ;) And if it was the tensioner, the sound wouldn't go away when the engine warms up.
5w40 made mine way louder.
Replace pistons.... That will fix it permanently 😎
.... And a rebore to the next size up.
@@stephenhunt6253 If the cylinder bores are worn or damaged, yes, but if the measure in spec, just a light hone and new pistons&rings should do. Measure the new pistons and compare with bore measurement, should give you an indication if re bore to next oversize is required
@@hansjoubert Yes, but most of the cylinders I've seen where the skirts are worn from piston slap, the bore is over spec too, and it's almost always cheaper to find a good used short block than to have a machine shop rebore (at least around here).
@@hansjoubert But the best course of action is, of course, to live with it. They can go 100s of thousands of km just fine with piston slap. ;)
@@stephenhunt6253 yup if you can find a good block, it would be cheaper
Aside from trying different oils, has the slap gotten worse from driving?
Nope. Same volume on startup, and goes away after 5 to 10 minutes.
Did it get worse?
Nope. 30k km later, still sounds the same when cold.
IT WILL CRACK YOUR FKING PISTON SKIRTS FFS!!!!!!!!
LOL!