julia_patel•15d agoMost Upvoted

Swapped to synthetic oil in my 2005 Civic and now it leaks everywhere

I put Mobil 1 in my old Honda last week and two days later I got a puddle under the front of the engine. Turns out the high detergent stuff cleaned out all the sludge that was plugging up my rear main seal. Anyone else run into this and just switch back to conventional or did you fix the leak?

3 comments

3 Comments

hayden_butler2713d ago

I read somewhere that synthetic has way stronger detergents that just dissolve all that built up gunk. Sounds like your old seals were basically relying on that sludge to stay sealed, same thing happened to my buddy's old Tahoe.

the_cole15d ago

That high detergent stuff cleaned out all the sludge" is what happened to me too. I bought a used Ford Ranger that had been running dino oil its whole life, put in synthetic, and suddenly had oil dripping down the bell housing. I actually just switched back to conventional and the leak stopped completely. That old seal must have been holding on by a thread and the synthetic just finished it off. Still driving it three years later with zero leaks on the cheap oil.

park.robin15d ago

Jumped in with my '97 Camry same way. Switched to synthetic at 180k miles after years of conventional, and within a week I had oil seeping from the valve cover gasket and rear main seal area. That stuff must be like soap, it just scrubbed everything loose. Went back to Valvoline conventional and the leaks dried up completely too, now at 230k miles and still no drips on the driveway. I guess you don't fix what isn't broken, especially with high mileage engines that have their own kind of balance going on.