Need some help and guidance. Have determined that I having large oil losses of oil after monitoring for the last 400-500 miles. My dip stick moves near the top mark of the dipstick to a 1/4 remaining space before the low mark. There is smattering of oil all over both value covers with an oil sludge the size of a peanut at the top gap of each value cover as well (See attached photos). I also have lots of oil that have fallen to my undercovers as well.

I'm thinking that at a minimum, I'll need to change the value covers. Would you all suggest using an oil dye to further assess if there are more leaks?

 

Miles? That rate of loss is usually a oil ring issue.

 

He's over 165k. The oil rings are a common issue on older/high mile cars that didn't have oil changed frequently by previous owners. This causes the floating oil rings to get sticky and allow oil to get past them. At the rate of loss you have, it's got to be more than just valve covers. It good that you caught it. Pull a couple of spark plugs for color inspection. You may find that it's time to replace them as well. A borescope inspection would be easy to do at this point. There are oil ring treatments to add to crankcase that dissolve the deposits and help loosen the rings. Having it done professionally at Toyota or Lexus ensures they use a Toyota approved product. Valve cover and oil pan gaskets can be done at the same time. There are other cleaner products besides Toyota, so an independent shop can do it as well. Let us know.

 

In your pictures that is sealant. It's normal for sealant to be applied on some mating surfaces. It's not oil sludge. Your valve covers look ok to me. They may not be perfect but I doubt your large oil loss is due to the valve covers. If your lower engine covers are covered in oil I would suspect your oil filter o-rings or oil housing is leaking. Are you dripping oil on the ground under the engine?

 

Hi guys, just a bit more information as I wasn't clear. The pictures I included are after I cleaned my value covers when was full of oil residue. I figured I should clean it throughly to determine if my value covers are leaking oil. That is when I saw what I think is dried oil sludge on the at the end of each valve cover and captured those pictures. No oil on the ground but lots of oil on the lower engine covers. Haven't driven the car much since my last post. I'm planning on checking leaks on top of the engine as best I can without oil dye. It seems that the oil dye has some mixed reviews on Amazon.

Thanks swfla for your suggestions. I did replace the spark plugs and spark plug seals about 3 weeks ago. All the tube seals were dried out and severely cracked. Almost all the spark plugs had lots of oil on the threads and as well as the tubes. I hadn't looked into piston ring treatments and that might be a step to take.

Had the opportunity to drive the car today for about 50 miles (stop/go on the freeway) and lost about 1/8 of the distance between low and the high mark on the oil dipstick.

 

you're clearly burning oil. Don't buy an oil treatment from a department store, do some internet research and get a pro type treatment. READ carefully as the engine must be driven a small amount and then an immediate oil change. You may even need two bottles as LS has high oil capacity.

 

I'd find the external leaks before trying an additive. This stuff has good reviews. My buddy and I flushed out his gs450h. Seemed to help.

 

Through monitoring for oil leaks, I found a couple of areas that are weeping. At the oil filler cap housing (little weeping) and at the oil filter housing (lots of oil). I bought the gaskets for both (part # 12196-38010 and 96722-24030).

Question - when changing out the Oil Filter adapter seals in the oil filter housing, will there be lots of oil loss? It seems that folks in this forum with previous post just popped off the 3 screws and changed out the 2 circular seals.

I bought the BG EPR Oil treatment per MikeT advice. Looking to try that after I fix some of these external oil leaks.

 

That's good news. Good job tracking the leak down, should be an easy fix. I've never replaced those gaskets. The only oil you'll likely spill is what's in the oil filter housing. Probably 1\2 quart give or take.

 

When you do the valve covers, you also need the seals for the high pressure fuel pumps as they must be removed to remove the valve covers. Also be sure to get ALL of the o-rings for the VVTI system as they clamp between the valve cover and cam towers on the head. Its a good time to go ahead and change the spark plugs also. I did all of this shortly after buying my LS460L a lil over 3 years ago.

Also, if your valve covers have been leaking a long time, the motor mounts are likely shot as well. I installed the aftermarket motor mounts. They work great and resolved the random vibration in the steering wheel at idle when stopped. Mounts looked 100% perfect until removed, but then the driver side once removed the stud in the top just flopped all around so wasn't dampening anything. The mounts can be replaced without removing the engine, but the front subframe will need to be dropped slightly. Did that myself as well.

 

Just an update. I replace both the oil filter housing and oil filler cap housing gaskets and it seems to have stop the leaks. I can finally put the undercover diapers back on.

Good news so far with the oil additive with 170 miles in. I ran the BG EPR for near 30 min at 1200 rpm. Change out the oil but wasn't as dark as I would have expected per the youtube videos. The car does seem to idle much smoother now. Must have clear up the piston rings for now. The misfires have stopped. TechStream had noted misfires on # 1, 5, 6 and , 7 in the past but showing 0 misfires now. Also, for some reason Catalytic Efficiency has improved significantly so that it is now safely passing the standard rather than throwing the CEL P420 on every drive. I'm hoping the engine doesn't degrade over time and monitoring the oil level for oil burning. Shout out to MikeT and swfla for your suggestions.

One weird thing is that I only needed 8 quarts for it to fill up half way of the dipstick versus 9.5 capacity per the manual. I'm suspecting that I might have some oil sludge in the oil plan. However, the oil plan is also dented from what I'm guessing was bad jack stands or a floor jack placements. The dents could also be the explanation why my car has lower capability and only took 8 quarts. Thinking at some point, I need to get the car back closer to its full capacity of oil.

 

I believe that the full mark is where 9.5 qts lands. Cold engine will give the highest reading. Is this reading when cold?

 

Yes, overnight cold is typically when I read it now. My car takes a long time for the oil levels to reach the highest level. Even 4 hours after turn it off, the oil level will still be rising.

 

This is from 2016 manual. I typically change out a little over 9 quarts with filter ( depends how long you let it drip out). Engine is full when the oil is at or just below the full line on the dip stick. It's pretty easy to fly past the full mark if you ad 1/4 quart too much.

Reading this one has to wonder how the same filter in awd holds .4 quarts more lol.