Oil Additives for Slowing Leaks

[ihgrad]

I curious as to opinions of this stuff. I have a 1996 Camry and looks like the rear main is leaking- I was hoping to slow it down and postpone the repair for awhile. Any thought about additives or other suggestions?

[DFBonnett]

Over the years, the few times I used the stuff brought mixed results. It never did any harm that I could notice.
FWIW
YMMV

[RIP]

Many use additives, many avoid them like the plague. It's one of those questions where you'll get many and varied opinions. Another choice would be one of the new "High Mileage" oils. They have an ingrediant that helps seals swell to prevent leaks in older cars. Could this "ingrediant" be the same as what is in some additives? I wonder.

[jdmccright]

I'm on the fence about it myself. I buy the high-mileage oils but I really wonder if causing old, brittle, rubber seals to swell is really a good thing to do...won't they just crack? If the seal is just worn, maybe it works and it can't hurt to try, but a true age crack in the seal won't be magically repaired by an additive.

The only oil additive I've seen that worked was Bardahl's No Smoke for stopping the bluish smoke from the tailpipe...not directly relevant to this topic, but it works by mainly thickening the oil, so maybe it might help reduce the leaking...in theory. But I wouldn't dump many different additives in at once. They might work against each other and cause sludge. Try one and drive it until time to change the oil. If it didn't work, try another after the oil change, and so on.

[somick]

I do agree with all the posters above, but I doubt that rear main seel will expand and stop leaking. This is rather a mechanical failure.

I have tried "stop leak" in the past with a front seal and it did not work. Had to replace it.

Sam

[Mike Gerber]

I am not a big fan of additives, other than fuel injection cleaners poured in to the tank. I doubt whether an additive will work to stop a rear main seal leak, but feel you have little to lose by trying. $5 compared to the cost to replace the rear main seal sounds to me like something worth trying. Like jdmccright suggested, try only one stopleak product at a time.

Good luck.

Mike

[Brian R.]

Don't use an additive that will radically change the viscosity of the oil. I have no data, but it is a change that could prove really costly.

[jdmccright]

I forgot to mention I tried a "stop leak" product (not Bardahl's brand) for my front cam seal. It didn't work...turns out the seal had cracked, so it never had a chance. Good thing the stuff was "guaranteed to work"...I'll be sending in my receipt for my money back!

I had the timing belt changed by a shop the first time...bet they didn't change the seals then because they were quite brittle when I popped 'em out. For the $15 spent on new seals, I'd change 'em along with every timing belt change. As for the rear crank seal, well.... I guess unless it's a significant leak, live with it until the tranny needs an overhaul. Something abt spending $500 to change a $5 seal grates on me.

[ihgrad]

Originally Posted by jdmccright

Something abt spending $500 to change a $5 seal grates on me.

Yeah, my friend always refers to cost of access- do what you can when you have things apart or it'll cost you more in the long run. Had that happen with my van- should replaced the coil pack while I had the engine apart... oh well, $400 lesson there... grrrr. Hopefully I WON'T have to overhaul the tranny any time soon, buuuuut... is 250k miles too much to ask of a transmission?

Funny thing about this leak: I don't see oil leaking any more- not even a drop for about a week anyway- after the 1st 100 miles after putting it all back together (it had been sitting completely drained for about 8 weeks). Any comments on that?