Let's talk AT-205 Re-Seal...

Let me just start and say I am very VERY skeptical about engine additives. Oil additives, fuel additives, coolant additives, head gasket sealers and the like are all bunk and usually do more harm than good.

So I've been chasing an oil leak...for about 40k miles...since 250k miles. Currently have 290k. I have been losing a quart every 1k miles or so. End of every month or two, I have to top her off again since the dipstick will be near low.

I changed the valve covers gaskets and inspected the half moons. I tried changing the gasket on the oil cooler but the damn thing was not coming off the block. I inspected and it didn't appear to be leaking.

I went for a bit and the valve covers didn't seem to be leaking anymore but was still getting oil on the steering rack. I saw that the valve cover bolts were loose so I pulled the intake and used thread locker and tightened them. I also checked around the valve covers and no real leaks.

Still she leaked. I was resigned to having a rear main seal leak and it seemed to be getting worse..

So Scotty Kilmer (love him or hate him but he knows cars) would rave about AT-205 and how cars went years after using it with no issues. I saw "Project Farm" did a test video which was damn convincing. Both claim to not shill for other companies.

So at 286k miles I dumped a bottle in. I just passed 290k and did an oil change this morning. I hadn't added any oil in that time (swear on my old man's grave) and when I pulled the dipstick, she was still at the FULL mark. Needless to say I was exceedingly surprised. I got underneath and checked the rack, and it had oil sludge on it that was drying out but not fresh oil like I was used to seeing when I checked other times.

So...looks like a win for now? I'm curious if it will destroy all the rubber gaskets over time? That's what I've heard the cheap additives would do. They'd swell up the rubber which works for a bit then the rubber just goes poof. "Supposedly" AT-205 doesn't do that. Still skeptical.

Anyone else have any experience?

I have owned my rig since NEW. I am the original owner so I thought long and hard about trying this "snake oil". I figured the worst case would be to just take her in and have the transmission pulled and the rear main seal replaced.

 

Thanks for the post. I am also skeptical of additives and I do not use them. Having said this, it is good to know that you've had a positive outcome out of this. You seem to be keen on keeping your vehicle. If you don't mind, perhaps you can periodically provide an update on how well the fix is holding.

 

I also have oil on the steering rack and I just replaced my RMS. I suspect crank seal or oil pan, but will know soon as timing belt change is coming soon. I am not afraid of additives at all, so if all else fails this is good to know. I got years and tens of 1000's of miles out of my dying tranny and dying head gasket in my Previa after using Lucas Tranny stuff and Bar's Head Gasket fix. I never suffered any adverse consequences from either one.

 

Oh, I'll be watching it for sure and will report.

I'm not sure AT-205 will really work for the RTV that TOYOTA used to seal the oil pan with....but maybe?

I know when the leak comes back, I'll get some of the blacklight additive and track it down for sure.

 

I have used Lucas stop leak on a couple engines which have worked well. They were not terrible leaks, but were also on cheap shitboxes I did not care too much about.