Hello everyone,
My father and I recently replaced the head gasket on my 2002 Mazda Protege DX (2.0L Engine). Since then, I have had a rough idle that I simply cannot get rid of. The car only has problems when at a complete stop or crawl speed (like moving up a car length in an intersection). When it is actually driving it runs smooth as can be, highway and backroads. The odd thing is that the car runs only slightly rough right after start up (when the engine is cold) and progresses to where it bogs out and dies/almost dies after the engine has warmed up. After the car is actually driven for any length of time, it has a fairly violent idle and dies within 30 seconds of stopping.
At first the idle was very rough and throwing only a P0300 code (Random Misfire). My dad and I tried many things to fix it including:
Replacing all coil packs and wires
Replacing all spark plugs
Replacing the EGR Valve
Replacing the PVC Valve
Replacing the IAC Censor
Cleaning the MAF Censor
Spraying throttle body cleaner around the intake manifold to check for leaks. (The engine did not rev, so we're guessing there's no intake leak.)
After doing all of this, nothing was fixed, but we did find that running the A/C made the car run smoother. My father also adjusted the idle up just a little bit. (Which I later read is not supposed to be messed with. (doh) ) It still had a rough idle, but was not at the point of dying, so I went with it.
Now after a week or so, the idle has gone back to almost dying, even with the A/C on. I did another OBD-II scan of the Check Engine light and now it it is throwing a P0302 code (Misfire in the 2nd cylinder) and P0171 (Engine Running Lean). We're now thinking that the fuel injectors may be the issue, but after a quick test (putting a screwdriver up to the injector and our ear to the other end.) It sounds like all for injectors are firing at a constant rate. So we're not sure there.
I am so frustrated and low on funds that I can't keep throwing money at the car if it's not going to fix it. The mechanics we've spoken too are pretty puzzled too and told us they'd be doing nothing more than guessing fixes too, and I can't pay them to guess, lol.
I didn't know if anyone on here had any advice on what to check next. Obviously with the head gasket repair, we took most of the engine apart to get to the head, so it could be a number of things wrong. We do however know that the head gasket was installed correctly, because there is no longer air bubbles in the coolant and the car does not overheat. So we do not believe that the misfire is due to the head gasket. Also I'll note that the actual problem with the "head gasket" was that the head was warped. An engine shop we took it to milled 8 thousandths off the head to get it flat again.
If any more info is needed, please let me know. Sorry this is so long, I wanted to be thorough since we've done quite a bit to the car already. Thanks!
My father and I recently replaced the head gasket on my 2002 Mazda Protege DX (2.0L Engine). Since then, I have had a rough idle that I simply cannot get rid of. The car only has problems when at a complete stop or crawl speed (like moving up a car length in an intersection). When it is actually driving it runs smooth as can be, highway and backroads. The odd thing is that the car runs only slightly rough right after start up (when the engine is cold) and progresses to where it bogs out and dies/almost dies after the engine has warmed up. After the car is actually driven for any length of time, it has a fairly violent idle and dies within 30 seconds of stopping.
At first the idle was very rough and throwing only a P0300 code (Random Misfire). My dad and I tried many things to fix it including:
Replacing all coil packs and wires
Replacing all spark plugs
Replacing the EGR Valve
Replacing the PVC Valve
Replacing the IAC Censor
Cleaning the MAF Censor
Spraying throttle body cleaner around the intake manifold to check for leaks. (The engine did not rev, so we're guessing there's no intake leak.)
After doing all of this, nothing was fixed, but we did find that running the A/C made the car run smoother. My father also adjusted the idle up just a little bit. (Which I later read is not supposed to be messed with. (doh) ) It still had a rough idle, but was not at the point of dying, so I went with it.
Now after a week or so, the idle has gone back to almost dying, even with the A/C on. I did another OBD-II scan of the Check Engine light and now it it is throwing a P0302 code (Misfire in the 2nd cylinder) and P0171 (Engine Running Lean). We're now thinking that the fuel injectors may be the issue, but after a quick test (putting a screwdriver up to the injector and our ear to the other end.) It sounds like all for injectors are firing at a constant rate. So we're not sure there.
I am so frustrated and low on funds that I can't keep throwing money at the car if it's not going to fix it. The mechanics we've spoken too are pretty puzzled too and told us they'd be doing nothing more than guessing fixes too, and I can't pay them to guess, lol.
I didn't know if anyone on here had any advice on what to check next. Obviously with the head gasket repair, we took most of the engine apart to get to the head, so it could be a number of things wrong. We do however know that the head gasket was installed correctly, because there is no longer air bubbles in the coolant and the car does not overheat. So we do not believe that the misfire is due to the head gasket. Also I'll note that the actual problem with the "head gasket" was that the head was warped. An engine shop we took it to milled 8 thousandths off the head to get it flat again.
If any more info is needed, please let me know. Sorry this is so long, I wanted to be thorough since we've done quite a bit to the car already. Thanks!