suloh

I have a 1992 LS 400 with 200K miles. I usually drive this car about town (10 miles daily max) but recently a project requires me to drive about 60 miles daily. This is when I started noticing that the car uses a quart of oil every 400 miles!

I understand from this forum that it might be a rear main seal leak. However, I looked under the car after parking it overnight and did not notice and major oil leaks. The car does not smoke when starting up and I do not notice any plume of smoke when taking off from a stop. Car idles perfect.

I am using Havoline 5-30. Do you guys think I should try and heavier oil given the mileage. Any suggestions on what weight I should try. How about a 20-50?

I live in Ca.

PS with the plastic engine splash tray underneath, could the rear main seal be leaking and yet I do not see it.

PureDrifter

iTrader: (10)

run a 10-40 and see how it is. i had a similar problem when i first switched to synthetic but after the switch it was fine.

im pretty sure that a 20-50 would damage the engine (tooo thick)

suloh

How much oil were you burning when using 5-30 synthetic?

Just went out and got some 10-40 as you suggested. Will give it a try.

PureDrifter

iTrader: (10)

5000 mi and it burned thru almost 2 quarts

suloh

Have been keeping an eye on the car and I can confirm it is the Rear Main Seal that is leaking

Will be changing oil to 10-40 havoline. Hopefully the thicker oil will reduce the oil leak. If that does not work, I will give Auto-Rx a try.