TonyGao

I have a 04 rx8 with a new motor runs 10000miles, yesterday while I am driving, the car stoped and can't start again, i notice the oil pressure is very low, so i follow the owner's manual to inspect the engine oil level, without adding any oil i can start the car, but the oil pressure is at a quarter bewteen mid and high. Now every time i want to start the car i have to inspect the engine oil level then it can be started(without adding any oil). I called the dealer they said the motor might broken, does anyone know why?

RIWWP

iTrader: (2)

By "inspect the engine oil" do you mean that you pull out the dipstick and look at it and put it back?

If that is all you are doing, then it has nothing at all to do with your ability to start the car. The motor has no way of telling when you pull the dipstick, and what you do with it when it's out.

Oil pressure on the gauge should be a bit right of center, but it's a dummy switch. If it's not there but all the way to the left, then the pressure is so low that running the engine is causing critical damage to it from a lack of oil. If you actually have oil in the oil pan and you don't have oil pressure, then it's possible that something got into your oil pan and blocked the pickup tube. Still means your engine is toast.



However, lets back up for a few minutes.

Can you go into more detail about how far you get with starting? What is happening, what isn't happening, what it feels like, what it sounds like, etc... You might just have a starting issue and an oil pressure sensor failure (independent of each other)

Loki

iTrader: (1)

Are you talking about the oil pressure gauge on the dash, or do you have a real one you installed? Because the one in the dash isn't really reliable. It's the 'everything is ok' gauge.

That sounds strange though, when you say you can't start, it cranks but doesn't fire up?

TonyGao

its the orginal gauge, can't start means cranks but doesn't fire up

TonyGao

inspect the engine oil" means pull out the dipstick and look at it and put it back. i just try to start the engine, after i insert the key and switch to on, i can see how much gas i have, but the oil pressure is at low and cant start, after I inspect the engine oil, it is still at low but can fire up and the oil pressure went to a quarter between mid and high, it feels like same as before, excepet i cant start the engine beofre " inspect the engine oil"

RIWWP

iTrader: (2)

Can you try just inserting the key and turning it to "on" but not "start" for about the same amount of time as it would take you to check the oil? Then try starting.

There is no possible way that there is an actual connection between the two. Something else is happening while you are doing that.

TonyGao

should the oil pressure point at mid before I start the engine?

RIWWP

iTrader: (2)

No, the oil pump is chain driven off of the e-shaft. If the engine isn't running the pump isn't moving. The pump starts moving as the engine starts rotating. There is a slight delay between start and when the oil pressure gauge will reflect the "ok" status of the oil pressure.



Starting to sound like this is just a starting problem, and has nothing to do with oil pressure

TonyGao

if the car runs for a while and i turn off the engine, it can be started again after half hour, but if i leave the car for a night, then the car can not start, i called the dealer they said i need to do the compression test to comfirm, which cost me couple hundreds dollors to do it, and if the results is bad i have to pay 5k to replace the motor, i am wondering if it worth it to do that. and i am worried will i damage the engine if i still runs the car

RIWWP

iTrader: (2)

Ok, this could be a few different things still. I would say that it is unlikely that compression loss is the root cause of your problem. Typically, compression loss will have no trouble starting cold, but get harder and harder to start when it's hot.

Battery: How old is your battery? Do you have anything aftermarket installed that taps into battery power? (usually audio or alarm related)

Coolant seal failure: Do you get any white smoke? Have you ever overheated? Is your coolant level slowly dropping? You could be getting a slow drain of coolant into a rotor housing, and once enough has drained in, it kills all combustion possibility until the coolant is swept out enough. If this is accurate, it would mean engine replacement to fix.




And if you actually do get a confirmed engine failure diagnosis, PLEASE don't pay the dealer. You will get a reman engine, possibly poor quality, and you will get overcharged for it. A cheaper option is to get a 0 miles quality rebuilt engine from Mazmart. Total would be around $3-3.5k (not sure their current prices) plus the labor of the swap itself, but you can probably get some local assistance with that, or at least the cheaper labor rates of a non-dealer mechanic. And the engine would be solid and good to go for at least 80k+. Remans don't typically last all that long compared to factory engines. Average quality is just too low for that.

TonyGao

thanks, the battery is good, i replaceed it half a year ago, my coolant level is slowly dropping, i just add it today by myself, last time i add is like 4 months ago. by the way, the coolant light is always on when i am driving and disappear after a few seconds

RIWWP

iTrader: (2)

If the coolant light is coming on and you actually have full fluid, then it's the common sensor failure. Otherwise it looks like you might have a failed coolant seal in the engine.