Less mileage means better compression? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

91ka · 07-22-2006, 08:21 PM

A shop (i wont name which shop but that its a reputable one) said theyd sell me a ka24de motor and tranny for $450. The only problem is that they dont know the mileage on the motor but mentioned that the compression was good.

So I was wondering if lets say for example, a 175,xxx motor could have good compression?

My current motor which has 210,xxx miles has 150 comp on all 4 cylinders. even with access chain grind noise, low fuel pressure (oil light on my gauge literally stays on), and some misfiring noise. The chain noise is so heavy that whenever i shift it makes BOV sounds.

post ur mileage when you did the compression test.

hitman · 07-22-2006, 09:18 PM

compression is just kinda like how well the cylinders are holding air. lots of people say 'good' compression, but that really doesnt mean anything, becuase if they arent giving you numbers i wouldnt beleive that they got any numbers. a old ass motor could have good compression, and a almost new motor could have terrible compression. but on the whole i would say lower miles higher compression, however i would not say becuase a motor has high compression it will have low miles, or vice verca.
good luck

CaoBoY · 07-22-2006, 10:56 PM

good compression, means valves arent bad, rings arent bad, headgasket isnt leaking etc. the cylinders arent leaking so to speak. doesnt matter how many miles on it, it could have been rebuilt.

gotta240 · 07-23-2006, 12:35 AM

you can have GREAT compression, but a spun rod bearing, a leaky headgasket(from coolant to outside of block) etc.... 150 comp. could actually be considered as "good" for your ka even though it has all those problems...

A comp. test is just ONE MORE THING to HELP verify a good motor..It shouldnt be the ONLY test or thing considered...

91ka · 07-23-2006, 06:13 PM

i guess i'll have to think about getting sr... lol

aznpoopy · 07-23-2006, 11:38 PM

Quote:

Originally Posted by 91ka

i guess i'll have to think about getting sr... lol

buying an imported sr carries the exact same risks...

sepulchral · 07-24-2006, 10:48 AM

you could have great compression my DD b16 had 220psi all the way across but burned oil like a bitch, the oil rings were shot

tre · 07-24-2006, 12:20 PM

LOL people use to think my car was turbo'd thanks to the timing chain rattle when you shift :P

Speed Motoring · 07-24-2006, 12:44 PM

If you decide to get the KA motor. Ask them for a start up warranty and how many days warranty on it etc. There are always risk of buying a used motor, just really have to check for signs of a bad motor.

Indolent · 07-24-2006, 12:50 PM

compression test it yourself if you can, i'd bring a starter, sparkplug socket, battery/jumper cables and a wire, thats what i did when i got my other motor, make sure there's no oil poured into the cylinders when comp testing. otherwise you'll get really good numbers lol or crank it a few times when all the spark plugs have been taken out

91ka · 07-24-2006, 09:17 PM

its weird. ive been looking for another motor because the current one has excess chain grinds to the point where it makes bov sounds everytime i shift. couple days ago my fuel pump died. but today i installed a new fuel pump and the problem was the fuel filter sitting on the floor of the fuel tank. lol after the new install the motor runs clean. no chain grinds whatsoever. even the oil light on the cluster is off. its been only one day but i'll post if the noise returns.

could a crappy fuel pump lead to chain noise?

this just IN!
after installing everything i just remembered replacing the o ring gasket for the fuel pump because the gasket stretched so much that i couldnt screw the bolts back in. get it? no pressure in fuel pump... i heard that oil flows only with pressure for ka's. could've this been the problem to my months and months of aganizing chain grinds???

07-22-2006, 08:21 PM	#1
91ka Leaky Injector Join Date: Oct 2005 Location: CA Posts: 99 Trader Rating: (0) Feedback Score: 0 reviews	Less mileage means better compression? A shop (i wont name which shop but that its a reputable one) said theyd sell me a ka24de motor and tranny for $450. The only problem is that they dont know the mileage on the motor but mentioned that the compression was good. So I was wondering if lets say for example, a 175,xxx motor could have good compression? My current motor which has 210,xxx miles has 150 comp on all 4 cylinders. even with access chain grind noise, low fuel pressure (oil light on my gauge literally stays on), and some misfiring noise. The chain noise is so heavy that whenever i shift it makes BOV sounds. post ur mileage when you did the compression test.

07-22-2006, 09:18 PM	#2
hitman Zilvia FREAK! Join Date: Mar 2006 Location: late 19th century prussia Age: 34 Posts: 1,057 Trader Rating: (3) Feedback Score: 3 reviews	compression is just kinda like how well the cylinders are holding air. lots of people say 'good' compression, but that really doesnt mean anything, becuase if they arent giving you numbers i wouldnt beleive that they got any numbers. a old ass motor could have good compression, and a almost new motor could have terrible compression. but on the whole i would say lower miles higher compression, however i would not say becuase a motor has high compression it will have low miles, or vice verca. good luck __________________ driftparty.com

07-22-2006, 10:56 PM	#3
CaoBoY Zilvia Addict Join Date: Feb 2005 Location: Central Valley Posts: 916 Trader Rating: (0) Feedback Score: 0 reviews	good compression, means valves arent bad, rings arent bad, headgasket isnt leaking etc. the cylinders arent leaking so to speak. doesnt matter how many miles on it, it could have been rebuilt. __________________ pulling outta the game: http://www.zilvia.net/f/showthread.p...wpost&t=119867 parting out, just let me know.

07-24-2006, 12:20 PM	#8
tre Zilvia Junkie Join Date: Apr 2006 Location: Seattle, WA Posts: 544 Trader Rating: (0) Feedback Score: 0 reviews	LOL people use to think my car was turbo'd thanks to the timing chain rattle when you shift :P __________________ I didn't buy an Audi because it is a Great Car, but for more of a reason to be an asshole.

07-24-2006, 12:44 PM	#9
Speed Motoring Join Date: Jun 2006 Location: Southern California - Brea City Posts: 46 Trader Rating: (0) Feedback Score: 0 reviews	If you decide to get the KA motor. Ask them for a start up warranty and how many days warranty on it etc. There are always risk of buying a used motor, just really have to check for signs of a bad motor. __________________ Welcome to Speed Motoring! www.speedmotoring.com We Carry: Massiv USA products, Versus Motorsport, Greddy, Redline Oil, Charge Speed, and much more! Recaro, Bride, Takata, Defi Gauges, ARC, Blitz, Veilside, Cusco, Exedy, Koyo Radiators, Fluidyne, Project Mu, Hose Techniques, and much more! Some Products Can Be Special Order. (Send me a PM, AIM or Email for more information)

07-23-2006, 12:35 AM	#4
gotta240 Post Whore! Join Date: Dec 2005 Location: so cal Posts: 3,496 Trader Rating: (21) Feedback Score: 21 reviews	you can have GREAT compression, but a spun rod bearing, a leaky headgasket(from coolant to outside of block) etc.... 150 comp. could actually be considered as "good" for your ka even though it has all those problems... A comp. test is just ONE MORE THING to HELP verify a good motor..It shouldnt be the ONLY test or thing considered...

07-23-2006, 06:13 PM	#5
91ka Leaky Injector Join Date: Oct 2005 Location: CA Posts: 99 Trader Rating: (0) Feedback Score: 0 reviews	i guess i'll have to think about getting sr... lol

07-24-2006, 10:48 AM	#7
sepulchral BANNED Join Date: Mar 2004 Location: Midlothian. VA Posts: 2,050 Trader Rating: (0) Feedback Score: 0 reviews	you could have great compression my DD b16 had 220psi all the way across but burned oil like a bitch, the oil rings were shot

07-24-2006, 12:50 PM	#10
Indolent Zilvia FREAK! Join Date: Jun 2005 Location: So. Cal, Riverside Area Posts: 1,110 Trader Rating: (3) Feedback Score: 3 reviews	compression test it yourself if you can, i'd bring a starter, sparkplug socket, battery/jumper cables and a wire, thats what i did when i got my other motor, make sure there's no oil poured into the cylinders when comp testing. otherwise you'll get really good numbers lol or crank it a few times when all the spark plugs have been taken out

07-24-2006, 09:17 PM	#11
91ka Leaky Injector Join Date: Oct 2005 Location: CA Posts: 99 Trader Rating: (0) Feedback Score: 0 reviews	its weird. ive been looking for another motor because the current one has excess chain grinds to the point where it makes bov sounds everytime i shift. couple days ago my fuel pump died. but today i installed a new fuel pump and the problem was the fuel filter sitting on the floor of the fuel tank. lol after the new install the motor runs clean. no chain grinds whatsoever. even the oil light on the cluster is off. its been only one day but i'll post if the noise returns. could a crappy fuel pump lead to chain noise? this just IN! after installing everything i just remembered replacing the o ring gasket for the fuel pump because the gasket stretched so much that i couldnt screw the bolts back in. get it? no pressure in fuel pump... i heard that oil flows only with pressure for ka's. could've this been the problem to my months and months of aganizing chain grinds???

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