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View Full Version : Seal Understanding..I need it?



jgcox6
03-22-2007, 02:44 PM
My 92 STX is either using oil or leaking (no drips on the driveway though). I have 203k miles on it and runs like a top. I know when I replace the timing belt, that I should replace the water pump, crankshaft seal and oil pump seal. Here is my question...will I "use" oil if my crankshaft seal and/or oil pump seal are needing replacing. I don't understand the mechanical part of that. Does the crankshaft not have oil in it? Why would a leak of oil hurt it. The same question for the oil pump...what is up with that...oil leaking from the oil pump back into the oil pan? or is it.. Just don't understand the reason for replacing them if they are in an oil environment already, Help me see the light..

T-spoon
03-22-2007, 02:51 PM
Those seals keep oil from leaking out of the engine. If you don't replace them, eventually they are very likely to lose their ability to seal completely and you'll start leaking oil out of the engine, which is not good, so if you're going to be in the area, you should replace them. Definitely never take a seal out and stick the old one back in because its ability to seal after that would really be questionable.

jgcox6
03-22-2007, 08:29 PM
shouldn't I see evidence of oil leaking out if they are bad...? I can't find an oil trail on the outside of the engine.

T-spoon
03-22-2007, 08:47 PM
Most likely, though if it's a small enough amount of oil leaking and burning off on top of the exhaust or some such you wouldn't necessarily see a drip. If it seems to be using oil without a leak though, you might try doing a compression test. It could be blow-by past the rings.

Fuelish
03-23-2007, 03:26 PM
My 92 STX is either using oil or leaking (no drips on the driveway though). I have 203k miles on it and runs like a top. I know when I replace the timing belt, that I should replace the water pump, crankshaft seal and oil pump seal. Here is my question...will I "use" oil if my crankshaft seal and/or oil pump seal are needing replacing. I don't understand the mechanical part of that. Does the crankshaft not have oil in it? Why would a leak of oil hurt it. The same question for the oil pump...what is up with that...oil leaking from the oil pump back into the oil pan? or is it.. Just don't understand the reason for replacing them if they are in an oil environment already, Help me see the light.. Am guessing the recommendation to replace all that is because you're in there already, and, at high mileage, tis better to be safe/proactive, rather than have to go back in and tear it all apart again a possible short time later. Consider it good preventive maintenence ;)

jgcox6
03-27-2007, 01:26 AM
Are the crankshaft seal and oil seal the same thing? or is the oil seal behind the crankshaft seal? :smokin:

farqy
03-28-2007, 04:03 PM
The worst side effect ( I think) of the oil pump, crank seal, cam seal(s) leaking oil is that they get oil on the timing belt, and then the timing belt fails or slips.

The crankshaft seal is in behind the crank pulley, so you will likely need a puller to get it off to change that seal. The oil pump will also be sealed, but sometimes you can buy a gasket for that, some people prefer RTV. The cam seal(s) can also be as problematic as the crank seal. If you are gonna change one, better change em' all.