Tiagz

I just bought another LS400(92), after helping to restore one for my brother that sat for 6 years last summer.

This new one has 30k More miles, around 170k. it also has sat but only for around a year. the Owner I bought it for loved the car and had it mostly dealer maintained however before sitting it was "loaned" to his daughter which may have ensued some neglect for around 8 months.

I bought it for around 500$ as the idler pulley had seized and it had ate its serpentine belt(before sitting). luckily i had a spare pulley from my brothers build and a new 20$ Dayco belt got everything working and let me drive home. It smoked on startup but i was kind of leaning towards a mix of condensation in the exhaust, thinned old oil and or the Idle up valve on the P/S pump.

I have deleted the idle up valve with the m14x1.50 drain plug, and vacuum caps on the ports on the intake. during this process I allowed the pcv valve to take a Mineral spirit bath. the PCV valve moves freely and didn't seem very dirty to begin with.

i expected it to burn the time i started after this as the valve was definitely leaking p/s into the intake.

However it continues to smoke. and quite heavily so i am kind of stuck with either very bad valve stem seals or a worn out cylinder(s)

My next step will be a compression test, If compression is good in all 8 ill lean towards sticky rings and possibly let some diesel sit on top of the pistons for a day or two turning the engine over by hand daily. the only thing that has me really confused is that our other LS that sat for 6 years never produced this kind of smoke, only has 30k fewer miles on it.

One thing I did today was empty out the gas in the tank as I have only added 10$ of premium with a jerrycan, however dumped it right into my infiniti g20 and noticed no ill effects so leaning away from bad gas. will have fresh fuel the next time i start it.

I did however grab the cheapest sale oil being Castrol GTX 5w30. I almost think switching to Rotella 15w40 would cause a lot less smoke and be the easiest "solution" I haven't driven the car yet either. as i've been changing all the fluids and sourcing a replacement front caliper from the wreckers as this was also seized. Maybe it just needs a good romp down the highway..


just wondering if anyone has experienced sticky rings on these engines before.. I was under the impression they were bulletproof. but even the one in the junkyard only has 170k Miles and forget when reading online that all these awesome reviews don't face a -30degree celsius winter.

PureDrifter

iTrader: (10)

not a common issue at all, but f the car was sitting it's possible. Albeit unlikely.

I would probably drive the car a few days, clean out the PCV beforehand. let i burn off whatever's been sitting in the cylinders.

djamps

Could be oil built up not just in the cylinders but in the intake/exhaust as well. When I soaked my cylinders for a few days with MMO it took a good 15 miles of hard driving before the smoke went away.

dicer

Check to see if the air filter is there, maybe the smoking is why the car just sat and wasn't used.

Tiagz

no it wasn't used as his daughter who was using it went to the mall with it, the bearing in the idler pulley seized


and it ate the serpentine belt.. the first time I started the car was without that belt on and I identified the failed

bearing 10 seconds after popping the hood. He had owned the car for the past 15 years and put a ton of money into it however purchased a 07 Ls460 and a nice new chevy 1500 so I think the Ls400 budget had gotten pretty low so it was never inspected once the belt snapped.

Air filter is there. decently clean, definitely not clogged with nothing making a nest inside.

PCV took a several day bath so pretty clean. Can always swap with the new oem one in my bros 91 that has about 5000 KM on it to test but highly doubt it.


I do have a borescope I can plug into my laptop (yay ebay) and I think ill pop the intake off tomorrow and check inside the intake to see if atf had pooled or what else is going on in there, then maybe look into the cylinders as well.


But djamps if your saying it took 15 miles of hard driving..

well it was a 7km babying in traffic trip to get the lexus home, On stale gas to boot, and all ive done since is back it in and out of the garage and let it idle after I had deleted the valve on the p/s and done fluid maintenance to the engine and driveline. so essentially, I need to take her out for a good spin and report back once I get the caliper swapped and brakes bled

dicer

I'd like to see a good close up of how those jack stands are engaging with the pinch welds. I'm guessing they are not.