low tension piston rings are cooked. how long do i have?
05-10-24, 02:48 PM
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low tension piston rings are cooked. how long do i have?
Hello guys,
It's my first post here on CL but ive been lurking for a couple of months. I bought my 2006 is350 8 months ago as a naive kid, knowing it had some oil burning issues. I thought, hey, these engines are pretty bulletproof, and with 158k miles I thought nothing could be that bad... right?
After driving it around for the past 8 months, putting very little miles as I was only visiting my friends and going to work in this thing, the oil burning got way worse. The car now has 161k on it and it burns oil like never before. Last fill up i burned half the engine's oil capacity in a gas tank (300+ miles I drive pretty conservatively). This damn thing burnt about 3.3 quarts in that amount of time! I know that it's normal for some older Lexus models to burn a little oil here and there, but this is a ridiculous amount of oil. (15-25 bucks extra for fill up if you aren't using "super tech" from walmart lol)
My buddy and I decided to try to do something about the problem, and we noticed the valve covers leaking a bit, so we went to go replace some gaskets. We open the engine up, everything is going smooth. Some problems start to rear their heads during this small job. Many bolts for the valve cover are completely missing, and it looks like the owner tried to use autozone UltraBlack to try to seal the gaskets before. Tons of residue to clean, lots of bolts missing. It was pretty messy. We bought this camera probe a couple months after I bought my car and we decided to take a good look into the cylinders while we had the intake manifold off.
Needless to say it was some nightmare ****. The camera goes in, and immediately I can see the shine of the oil pooling on top of my pistons in a thin layer, we checked all the cylinders on the driver's side and they all had a similar amount of pooling, with the center cylinder being the best case. We know it wasn't coming from the spark plug tube seals because when we took the spark plugs out there was no oil on them. Taking a second look at the spark plugs we can see some ashy buildup down past the ring, with one side being clean as if it was being washed by the oil.
We stick the camera down one more time to see how screwed I am. To my horror in cylinders 2 and 6 (Driver's side), we see some metal poking out past the piston on the perimeter. ****. My piston rings are cooked. Cylinder 2 was the worst offender, because it looks like someone took a dime and stuck it between my cylinder wall and piston. So this was definitely the cause of my oil loss issue.
I will provide some pictures when I get back in there to redo the valve cover, I'm just waiting on some bolts from Rat2.The car still runs fine, and has a decent amount of power, but I wonder how much torque I'm missing out on.
Has anyone had any experience with this? How long did your engine last? Where did you go to buy a new one?
Thanks in advance I look forward to hearing from you guys!
It's my first post here on CL but ive been lurking for a couple of months. I bought my 2006 is350 8 months ago as a naive kid, knowing it had some oil burning issues. I thought, hey, these engines are pretty bulletproof, and with 158k miles I thought nothing could be that bad... right?
After driving it around for the past 8 months, putting very little miles as I was only visiting my friends and going to work in this thing, the oil burning got way worse. The car now has 161k on it and it burns oil like never before. Last fill up i burned half the engine's oil capacity in a gas tank (300+ miles I drive pretty conservatively). This damn thing burnt about 3.3 quarts in that amount of time! I know that it's normal for some older Lexus models to burn a little oil here and there, but this is a ridiculous amount of oil. (15-25 bucks extra for fill up if you aren't using "super tech" from walmart lol)
My buddy and I decided to try to do something about the problem, and we noticed the valve covers leaking a bit, so we went to go replace some gaskets. We open the engine up, everything is going smooth. Some problems start to rear their heads during this small job. Many bolts for the valve cover are completely missing, and it looks like the owner tried to use autozone UltraBlack to try to seal the gaskets before. Tons of residue to clean, lots of bolts missing. It was pretty messy. We bought this camera probe a couple months after I bought my car and we decided to take a good look into the cylinders while we had the intake manifold off.
Needless to say it was some nightmare ****. The camera goes in, and immediately I can see the shine of the oil pooling on top of my pistons in a thin layer, we checked all the cylinders on the driver's side and they all had a similar amount of pooling, with the center cylinder being the best case. We know it wasn't coming from the spark plug tube seals because when we took the spark plugs out there was no oil on them. Taking a second look at the spark plugs we can see some ashy buildup down past the ring, with one side being clean as if it was being washed by the oil.
We stick the camera down one more time to see how screwed I am. To my horror in cylinders 2 and 6 (Driver's side), we see some metal poking out past the piston on the perimeter. ****. My piston rings are cooked. Cylinder 2 was the worst offender, because it looks like someone took a dime and stuck it between my cylinder wall and piston. So this was definitely the cause of my oil loss issue.
I will provide some pictures when I get back in there to redo the valve cover, I'm just waiting on some bolts from Rat2.The car still runs fine, and has a decent amount of power, but I wonder how much torque I'm missing out on.
Has anyone had any experience with this? How long did your engine last? Where did you go to buy a new one?
Thanks in advance I look forward to hearing from you guys!
Last edited by makis350; 05-10-24 at 03:10 PM.
05-10-24, 07:17 PM
#2
You may have a problem with valve seals as well, it could be a combination of things for oil burning issue. Lots of threads about is350 burning oil here. I was able to bring mine to a reasonable oil consumption around a 1L per 2k or so. book says 1L per 1000km so it's ok. I used all kinds of additives, replaced pcv valve and valve cover gaskets. I suspect that my valve seals are rock hard because spark plug tube seals were cracking when I was replacing them. So you may have oil draining past the valve steam seals and ****ty oil scraping rings is a given. I got 310000km on it now. drives well but if I punch it hard it will burn more oil.
05-14-24, 11:41 AM
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2nd gear
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Hey Mr Fsport you're a legend btw
Thanks for reading and replying to my post I appreciate it brother. I've started scavenging local junkyards and "engine resellers" and looks like i can get a decent used one for around 1700-2k. Yeah. Might be a little while before I can afford that lol.
In regards to the piston rings, cylinder 6 is the only cylinder where I can see the piston ring is actually damaged the most. It almost looks like there is a hole in the piston itself on the very edge but I'm 90% sure its the ring. Cylinder 2 had a really badly melted piston ring, the metal was melted, spread and poking up past the side of the piston, which is just creating a massive gap for oil to come through. Like I described in the original post it looked like someone took a dime and shoved it between my piston and block. It is only on one side on both pistons, which gives me some hope. The multilayer design means that only one layer could be messed up but It's hard to tell. If its already melted by the top then the entire ring is probably cooked.
Cheers!
Thanks for reading and replying to my post I appreciate it brother. I've started scavenging local junkyards and "engine resellers" and looks like i can get a decent used one for around 1700-2k. Yeah. Might be a little while before I can afford that lol.
In regards to the piston rings, cylinder 6 is the only cylinder where I can see the piston ring is actually damaged the most. It almost looks like there is a hole in the piston itself on the very edge but I'm 90% sure its the ring. Cylinder 2 had a really badly melted piston ring, the metal was melted, spread and poking up past the side of the piston, which is just creating a massive gap for oil to come through. Like I described in the original post it looked like someone took a dime and shoved it between my piston and block. It is only on one side on both pistons, which gives me some hope. The multilayer design means that only one layer could be messed up but It's hard to tell. If its already melted by the top then the entire ring is probably cooked.
Cheers!
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