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Alexzepeda
11-29-2011, 02:25 PM
YO! My first post on the forum! Whoot whoot! lol I have a '92 240 Coupe with a KA24 de, bought the car from a friend and he said that cylinder 2 and 3 have low pressure. Would that be because of piston or piston ring? Debating weather I should buy a rebuild kit or just a new engine.
Darren
11-29-2011, 02:38 PM
Piston's don't seal, rings do so it's either a ring, or could be your valves not closing all the way.

By far the most cost effective way of going is to purchase a low mileage replacement, you could even upgrade to the DOHC for just a little extra and get a slightly better motor, or if you've got some cash, upgrade to the sr20... this would be the best bang for the buck, imho
yetijeff
11-29-2011, 03:38 PM
Piston's don't seal, rings do so it's either a ring, or could be your valves not closing all the way.

By far the most cost effective way of going is to purchase a low mileage replacement, you could even upgrade to the DOHC for just a little extra and get a slightly better motor, or if you've got some cash, upgrade to the sr20... this would be the best bang for the buck, imho

DE=dual cam. Is it puffin any smoke? Do a compression and see how low they actually are. Check ur fan and see what's in range for "ok" u gotta remember that ur dealin with a 20 year old car so the likeliness that ur engine compression is a little low is high. If the psi range between all four cylinders is close and it's not smokin then roll with it. If it is smokin it could be your rings...
Alexzepeda
11-29-2011, 03:58 PM
Well the car doesn't start, so I can't tell you if its white smoke or not. It sounds like it wants to start.
Cylinder 1 has 150, Cylinder 2 has 30, cylinder 3 has 130, and cylinder 4 has 150.
bad dog
11-29-2011, 04:04 PM
it could also be a bad head gasket .
yetijeff
11-29-2011, 07:28 PM
it could also be a bad head gasket .

Tru tru. If u wanna see if the head gasket is bad drain the coolant. If there's a suspicious white or brownish sludge milky substance than most likely it's popped. Or vice versa check your oil and see if there's coolant on the dipstick. If neither one is present then it doesn't necessarily mean that it's ok but that's usually a tell tale sign. Before goin out and buying a new motor or a rebuild kit, pull the head and take a look at the valves see if they're bent burned or just look more fuct than anything else, and at the same time check the head gasket for cracks etc. Getting a valve job/new head, or headgasket is waaaay cheaper than rebuilding the whole thing and if u do en up rebuilding you'll need a new one anyways...
jr_ss
11-29-2011, 07:54 PM
Just do a leak down test... Bubbles in the coolant, headgasket... Tons of air coming from oil fill hole, rings. Air in either intake or exhaust, valves...
cotbu
11-29-2011, 09:29 PM
Leak down test FTW! But if you're not ready to rebuild why bother, look for a replacement or upgrade!
r33nota240
11-30-2011, 06:17 PM
quick way to tell is get a oil cap off a quart of oil fill it with oil dump it in the cyl through the spark plug hole and do a compression test if its bad rings it will seal long enough to bring the compression up if no change its either a head gasket or a valve not seating