car died...

[E30MACK]

last night Im driving home, the car slowly starts to sputter...like a misfire. and real quickly it goes from bad to worse. I thought immediately it was from earlier in the day when I put 89 octane in it instead of the 93 that I have been(give me a break I only had $4 and gas aint cheap). I limped it to a gas station and put some 93 octane in it and then headed back on to the highway. started up a again, limped it to another gas station to check fluids and when I tried starting it again it wouldnt start. Any Ideas?
Also, with in the last 4 days the car has started to emit white smoke under acceleration. smells like Im burning oil, its not a huge puff or anything but its enought to see in my rearview mirror.

[Sagaris]

Check for a bad head gasket. A quick (but not always reliable) check is to look for chocolate milk /milkshake under the oil cap (water mixed with oil).

Check the coolant and see if it looks dirty/muddy.

This isnt always a sure sign of a bad head gasket since oil is hygroscopic (absorbs water) and an engine that hasn't reached operating temperature can have a milky oil cap due to condensation that hasn't been evaporated by a hot engine. Also sometimes oil coolers can fail and allow oil and coolant to mix, but anticipate the head gasket being bad since that is the more common occurence. You can also check the compression and will see a large drop in compression on one or more cylinders (likely adjacent cylinders if the head gasket failed between them ). Has your engine overheated or been running hot recently?

[jlevie]

An E30 with the stock engine only needs (or wants) 87 octane fuel. So the gas you used isn't the cause of this. My first thoughts would be of the fuel system or CPS.

The white smoke from the exhaust is probably a leaking head gasket. Oil smoke is blue and gas smoke is black.

[E30MACK]

yeah I though it may have been a head gasket on first thought as well, checked both oil and coolant though and no mixture... I was gonna do a compression test tonight but alas I didnt make it home! and no I have not been over heating at all.

[Huff]

You mentioned mis-firing.. Could be a bad ECU too.. They usual make the car go crazy when they start to die

[E30MACK]

hmmm, how would you check in order to rule the ECU out?

[LJ851]

hmmm, how would you check in order to rule the ECU out?

Replace ECU with known good one. BTW my bone stock '89 325is will audibly ping on most 89 octane fuels.

[E30MACK]

yeah...thats what I thought, Im not gonna stop using premium...even if it is costing me an arm and a leg.

[Cletonius]

BTW my bone stock '89 325is will audibly ping on most 89 octane fuels.

All I ever seem to hear is valve tick.

yeah...thats what I thought, Im not gonna stop using premium...even if it is costing me an arm and a leg.

here in chicago it's only like a quarter more, not much in the hrand scheme of things, maybe $5/tank.

[E30MACK]

called the shop where I pushed it(lol)....they said that my fuel pressure was low....like 20psi instead of 40psi(which is where Im told it was supposed to be) any guesses as to why it would be that low? also that I need a new starter.....

[jlevie]

Low fuel pressure could be; a clogged filter, failing pump, or failing FPR. Replace the filter and test the system (see the Bentley manual) to assess the condition of the FPR and pump.

[E30MACK]

just replaced the filter like a month ago...will most likely change fuel pump and regulator when I get it back to the house.

[Heysüß]

keep us posted.

[E30MACK]

so I changed the fuel pump and starter, started right up ran fine for alittle bit and then had the same surging issues anywhere from about 2k rpm and up. it ran ok for about 5 min until it started up again. so I am not sure what to check at this point.

[jlevie]

The first thing to do about the unstable idle is to have a smoke test run on the intake to find leaks.