Originally Posted by BlackOmega
Sometimes its not always what you think it is. And some cars wont start with the valve cover off because the crankcase is pressurized. And even if it does start with the cover off, that doesnt mean itll keep pressure when it gets hot.
not quite true. there is pressure in the crankcase, but it's not positive pressure. the reason a car may/may not start with the valve cover off is because the block itself is part of the vacuum system. Pull the cover off (or even take off the oil cap) and you've created a big vacuum leak. oh, and it'll never have pressure with the cover off (vacuum pressure that is)
(sorry, bit of a car nut, I own an old datsun Z lmao)
there's a better way to test the oil pump taht won't destroy the car. find out how you can prime the oil pump with a drill, and just crank the pump to see if you have oil pressure. Oil pumps are one of those things that don't really fail though. if they do fail though, the engine will sort of...grenade, or seize, and then won't even crank over (you'll get a click, and that's it, and you won't be able to manually turn over the engine)
if it's cold weather that damaged the car, it would be because the engine wasn't warmed up enough, and you damaged the bearings on either the crank or the rods. thick oil doesn't flow well, so if the oil is thick enough, the bearings won't get much oil till it all warms up nice. ALSO, the pistons won't be expanded properly, and giving it too much stress or reving it can cause the pistons to wiggle in the cylinders and break the skirts off, causing a lot of problems (broken riglands and tons of knocking)
same goes for the bearings. if you starve a bearing it'll seize and spin in place, totally cutting off all oil to the bearing and causing a ton of knocking.
as for the transmission though....if it's an auto, sorry you're out of luck there. there's no point diagnosing those...if they go, you've got no choice but bringing it to a shop to rebuild or get a replacement. stupid auto's. at least with manuals you can rebuild them on your own if you know enough mechanicsEdited by Nenkitsune - 12/6/08 at 4:52am