Used to stop an oil leak between the block and intake. Applied as directed and reduced leak by 90%.Stopped my little cover for my fuel distribution pump from leaking oil.This item is for a quick fix if you're missing a gasket, it also works better with gaskets if you want a engine parts sealed probably this item is perfect to have in a pinch.I got this to seal up the uneven areas underneath my valve cover where the camshaft sprockets are, and it did an excellent job. The sealant prevents the oil from seeping out and after 24 hours, it cured well.The only negative was the flimsy tubing material. Although I was squeezing from the bottom of the tube and upward, a small pin hole-size spot ripped open, forcing me to throw away the remainder of the sealant.4 stars.Regularly use a small bead to seal upper plenum for extra security.Recently used it to seal rocker covers (valve covers & gaskets) and it worked perfectly.Did the job wellI have never had problems with PirmTex silicon products. That being said I highly recommend thisGoodI used this gasket compound to reseal the auger drive gear assembly on my snowblower. Follow the instructions to a tee and away you go.Bueno y baratoVery useful. Quality product. Permatex never disappoints me.No lo recomiendo. Mala calidad. Producto muy deficiente para su aplicación. Perdida de dinero y tiempo.Best quality RTV period