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Figured you might say something scary like that, any recommendations on leak down kits? I have a compression tester but I know that doesnt tell as much
No need to spend a whole lot of money on one. As long as the gauges read the same with the same pressure applied, you're good to go. There's no magic involved here.
Have you tried changing the oil with warm new oil (to flow down to the sump quicker) and very slow refilling, the only thing i can think of is the rocker (on the fill side) filling up with oil and letting oil past the valve guide seals, i have never heard of this in any car before? even old 350 chevys with worn guides cheers.
Have you tried changing the oil with warm new oil (to flow down to the sump quicker) and very slow refilling, the only thing i can think of is the rocker (on the fill side) filling up with oil and letting oil past the valve guide seals, i have never heard of this in any car before? even old 350 chevys with worn guides cheers.
It’s these kind of ideas that I like to entertain, there is a possibility however, it’s not the first time the engine starts that it has this issue. It’s the first 500 miles or so multiple engine cycles. Where the oil fill cap is I don’t think there would be anything that the oil gets to when pouring it in that oil doesn’t get too with the engine running normally?
Which brings into question does new oil or certain types of oil give off flammable gases when they are heated up for the first 10+ times causing detonation?
It’s these kind of ideas that I like to entertain, there is a possibility however, it’s not the first time the engine starts that it has this issue. It’s the first 500 miles or so multiple engine cycles. Where the oil fill cap is I don’t think there would be anything that the oil gets to when pouring it in that oil doesn’t get too with the engine running normally?
Which brings into question does new oil or certain types of oil give off flammable gases when they are heated up for the first 10+ times causing detonation?
It shouldn't unless there's something absolutely quirky with Amsoil.
I've been doing oil changes since 88k and my 2011 is now at 250k on stock tune.
I used Pennzoil Platinum then Ultra Platinum for the longest time.
Now I've been using Kirkland Signature.
Never experience the car having this behavior. And I dump all 10qts in.
Odd issue for sure, I've done all my own oil changes on my last 3 2UR cars and have never experienced this issue and I was never too particular about the level either,
I’m running with an aos lobux, and had issues previous with the gen 1 version from RR, had vacuum leaks which included light knock (also at low throttle input) and rough idling. With this particular issue I dont believe the AOS has anything to do with cause it was not touched. All of the connections are secure and vacuum free. I know the smallest vacuum leak an be a nightmare, they aren’t easy to find
Grasping at straws here but have you checked the wing bolt on the underside of the aos? I've had a vaccum leak from there before. Now I check it's tight every time I empty the can.
Small update, I've managed to reduce (not eliminate) a noticeable amount of the low load knock after cleaning the maf, replacing some of the clamps on the vacuum lines, and reinstalling the intake tube assembly.
The biggest improvement came after I went over the hoses and reinstalled the intake tube. Specifically for me the vapor feed hose at the VSV had a loose connection with the factory clamp so I swapped it out to a small worm gear.
There was another small noticeable improvement after a maf cleaning. I used a few q tips and 91 rubbing alcohol to clean it. The long term fuel trims are now less than 1% variance between banks (down from 1.5-3%) and low load knock was further reduced. I run an oiled air filter for the record.
as far as knock feedback behavior; its stuck at 3 more, a lot less 5-6. I didnt gain any overall KLCV but it comes up to 24.5 a lot easier/faster and when it does drop it only drops to upper 23's instead of 20-22
Great update. Thanks for bringing the goods on what you did and what your results look like, even if it isn't the outcome you had hoped for in the beginning.
It's at least at a point where I don't feel the need to constantly look at it. I suspect there's another small intake leak somewhere. I know my brake booster needs to be addressed from leaking down(hard pedal), and a new set of injector orings may not hurt. Another kind of odd thought I had was the dipstick tube. I have EL headers and the tube had to be bent and was very hard to get in. If that seal isnt good and seated could a leak there cause issues with the maf reading?
It's at least at a point where I don't feel the need to constantly look at it. I suspect there's another small intake leak somewhere. I know my brake booster needs to be addressed from leaking down(hard pedal), and a new set of injector orings may not hurt. Another kind of odd thought I had was the dipstick tube. I have EL headers and the tube had to be bent and was very hard to get in. If that seal isnt good and seated could a leak there cause issues with the maf reading?
I had MAF efficiency DTCs recently with cracked "ventilation hoses" - the hoses from the valve covers to the intake tube. I could see it possible for the same fault if the oil dipstick was not sealing properly and leaking air.
FWIW, I have the GESI catted UEL headers now, and I've not been able to get the cat efficiency DTCs to go away yet. Very frustrating, but glad to have OBD Diagnostics on my VLine to clear the errors immediately.
Add me to the list experiencing this. This past oil change is the first time this has happened detrimentally (my KCLV dropped from low 20s to high teens last change but wasn't hugely noticable). It's been three days and about 50 miles and I'm having the same severe symptoms noted above; KCLV crashing to low single digits (around 5) when at low throttle input. KCLV increases easily with more aggressive throttle but crashes again when cruising. Same oil as last oil change, Costco 5w-30 with OEM oil filter will update when the issue stops.
No AOS or aftermarket air filter here. No mods since last oil change (headers and tune were done about a month before my prior oil change).
1. make sure your oil cap has a gasket on it
2. Check that the dipstick itself has a small oring on the yellow handle
3. (hard one) check the dipstick tube going into the oil pan, make sure its seated and not leaking. It also has a small o ring
4. check the valve cover vent tubes going into the intake for cracks (that means pull them off and look at each end of the tube for cracks)
5. (pic attached) inspect both vacuum hoses on the EVAP valve, again pull them off and look at each end of the tube.
keep in mind if the vacuum lines are hard, there's a good chance they might come off damaged beyond use. If you don't have something to replace them with you could be stranded.
1. make sure your oil cap has a gasket on it
2. Check that the dipstick itself has a small oring on the yellow handle
3. (hard one) check the dipstick tube going into the oil pan, make sure its seated and not leaking
4. check the valve cover vent tubes going into the intake for cracks (that means pull them off and look at each end of the tube for cracks)
5. (pic attached) inspect both vacuum hoses on the EVAP valve, again pull them off and look at each end of the tube.
keep in mind if the vacuum lines are hard, there's a good chance they might come off damaged beyond use. If you don't have something to replace them with you could be stranded.
Small piece of G2: you can cut the hoses going to the valve covers and reattach them if they're cracked. AMHIK. I have replacements on order, but one of them is on backorder from rural Siberia.
Don't forget the PCV hose and PCV valve. If either of those are leaking (or you put someone's AOS on there) you could have significant issues.
Add me to the list experiencing this. This past oil change is the first time this has happened detrimentally (my KCLV dropped from low 20s to high teens last change but wasn't hugely noticable). It's been three days and about 50 miles and I'm having the same severe symptoms noted above; KCLV crashing to low single digits (around 5) when at low throttle input. KCLV increases easily with more aggressive throttle but crashes again when cruising. Same oil as last oil change, Costco 5w-30 with OEM oil filter will update when the issue stops.
No AOS or aftermarket air filter here. No mods since last oil change (headers and tune were done about a month before my prior oil change).
OPs car & mine tends to get back to normal KCLV readings right around 500 miles of driving. After an oil change.
Random thought but is it worth noting on all these "instances" of oil change/KCLV drops to list year and mileage of vehicle to maybe narrow down wear and tear or age of hoses etc? I don't believe anyone has called out their info except post #3.
05-04-23, 04:40 PM
