meg1234

Ok so I am looking for a new car, I found one for $1750, but I sent it in for a diagnostics test (I know nothing about cars) and they said the only problem with it is that cylinder 2,3,4 ran at 150 psi and cylinder 1 ran at 120

so is this a big problem? (if i buy the car will it break down fast) and how much would it cost me to get this fixed?

thanks

Anon51

that motor may need new rings or the valves aren't sealing right. besides 150 being kind of low depending on the mileage of the motor. i'm guessing the rings would cost anywhere from 400+ where as valves would be 600+ again depending on the motor.

builthatch

it all depends. they probably did a basic compression test to give you those numbers. the numbers are somewhat arbitrary as it depends on the gauge they use, but the main key is consistency from one cylinder to the next. if the deviation is too far then it will be apparent you have an issue. further tests can tell exactly where the issue is. one test is called a leakdown test. they fill the cylinder with air and measure how much leaves. on an engine that has shown to be down on compression already (such as yours) the benefit to the leakdown test is you can tell where it's leaking, which in turn will help give you a better idea of how catastrophic the problem is.

in all honesty, it might be worth driving it as is. yes, that is a decent deviation, but it's not a dead cylinder so for the price of that car i'd probably try to just drive it and see what happens. if it's a worn ring set or a damaged valve seat it will drive just fine, but might consume some oil or not get the gas mileage it would if it was perfect. it might drive for years in that condition.

keep in mind, when you look into internal engine work, it might get to a certain point where you might want to consider swapping the engine for a known-good engine with lower mileage, instead of fixing the one you have. but it depends on how bad the damage is, how good of a condition the rest of the engine is in, and what kind of talent you have around you in terms of shops who can do the work, etc.

this is who i use when i need a replacement engine - http://www.hmotorsonline.com/shop/contact_us.html

Former User

I think you should continue shopping for a similarly priced car in which the cylinder compressions never deviate more than 10% between any of the cylinders. I think you will find one.

builthatch

oh crap, i didn't notice that the OP didn't already purchase it.

i agree with Ron, looks elsewhere.