DundukovEM

Hi everybody!

I'm new to this forum, but not a beginner for this car.
2003 Lexus GS300, 218 KMiles. I own it more than 5 years and have a large sheet of work done on it.

In the last month I encountered the following problem:
During driving, the oil seeps through the base of the oil dipstick tube.
Not much, but day after day it accumulates, and then it goes down on the oil pan.

Today, I removed the oil dipstick tube from the engine block, washed everything out, replaced the tube O-Ring (96721-19010) and put it back in.
In the parking lot at idle speed nothing seeps.
So I did a test run a few miles, came back and checked again -> absolutely the same oil seepage as before the replacement of the O-ring.

Also, there is another unbeatable problem. Small leakage of the front crankshaft oil seal.
Why do I say unbeatable, because I replaced four times this oil seal a year ago. Three different brand (2xOEM+National+Beck Arnley), tighten the seal spring - NOTHING!
Absolutely the same small leakage only when driving.

I suspect that when driving (so the engine is under load), an increased pressure of the crankcase gases accumulates in the oil pan.
I think, this is most likely due to the wear of the bores and rings in the cylinder-piston groups.
Unfortunately, now, I cannot diagnose (measuring the compression) and/or fix it. No garage and time.
I also do not intend to change the engine. The total leakage of oil is small.
Rather, it creates moral pressure (because everything else is perfect), and dirt on car under body after a time.

When I changed the O-ring on the dipstick tube, I noticed that the tube had a vulcanized rubber base.
See the attached picture. Sorry, this is not a real picture of my tube. Just borrowed on the Internet.
At the moment, since it's not replaceable, I decided to replace the entire dipstick tube (11452-46010) with a new one and see what it does.
Waiting for the delivery of spare parts. Will be in 7-10 days.

I will be glad to hear new ideas and considerations on the topic.
Thank you!



Dipstick Tube

KTGS300

Sorry to resurrect this post, but do you have an update on your dipstick situation? Mine started to do the same thing and wanted to know if I should get the entire tube assembly or just the O-ring.

DundukovEM

Mine has been fine since then. Only replace the O-ring.

dwoods801

Make sure to add some synthetic grease to the o-ring before installing it so that it doesn’t bind up when installing it. Unless something is bent or damaged, just the o-ring should be required. I am not as sure about the 2JZ, but I know on the V8, the oil filter attachment section is right below where the dipstick enters the oil pan. And there is gasket in the pickup housing that also leaks and it’s hard to tell what the source of the oil leak is, so I have just replaced both these o-rings at the same time.