Hey guys, bought this e30 m50 for next to nothing, figured I'd make it better and keep her for my pleasure. Swap was clearly done piss poorly, nothing worked when first got it. Slowly been babying her back to par. Now the problems I'm having are related to my air fuel ratio. I believe my car is running in "limp mode" due to jmproper hookups. My car stalls when I plug in maf, but runs decent without it. I've looked under the car at the o2 sensor as well, and to my surprise theres one actually sticking out of the pipe, however, there's about 6 inches of wire coming off, that isn't hooked to anything. The part that comes from the car is down there, just not hooked up, o2 sensor has four wires, and the wire coming from car has 4 wires. I'm so puzzled by this, any help would be greatly appreciated. Thanks!
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First off, start by checking the OBD error codes. That should start leading you down the path to salvation. -
As I said, po swapped engine, check engine light has been blinking since I got the car. Tried hooking it up, no connection.Comment
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I read what you said... Get your check engine light working and/or learn how to pull the codes before replacing random parts.Originally posted by bradp0rter View PostComment
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Any idea on how to do that? I'm pretty car savvy but this stuff is confusing.Comment
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Assuming that you do have an M50 (not M52) and it is OBD I (not OBD II) then you can follow the instructions here to pull the codes. It's commonly referred to as the "stomp test".
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Tried stomp test... Cel stayed flashing. No pauses nothing.Comment
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This may be a stupid question, but I need to ask it. You're not looking at the "Check" light centered in the cluster? As seen here.
The only time a Check Engine light should be flashing is either while returning codes or while the engine is actively misfiring. I could be mistaken but I don't believe there is a "limp mode" with this engine management. You could be down a cylinder or two if the misfire is constant. Maybe a coilpack is bad, maybe your head is cracked... it's just a guessing game without pulling the stored codes from the ECU. If you can extract them with the stomp method, then I'd suggest finding a shop with a code reader that can interface with the BMW diagnostics port.Comment
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1. Pull out your coilpacks and check for oil around or in the spark plug housings.
2. If your car runs better w/out the MAF, the MAF is bad
When the ECU cannot get good readings from a bad MAF it will overcompensate, no reading is a generic map
3. o2 sensor needs to be in the exhaust pipe not hanging out
It sounds like you've got a few things to troubleshoot and the above is how I would proceed. Treat these issues as separate.
If you do have oil on your coilpack boots, it's from the valve cover gasket, order a new valve cover gasket set and be sure it center the new one on well when you place the valve cover back on and use new mounting hardware. Bentley manual comes in handy.
If there's not oil do a compression test on the cylinders. If you have a cylinder(s) with lower compression than others you can also do a leak down test. Before you finish the compression test, drop a small amount of oil in the lower compression cylinders, if any, and you will know that the piston rings are bad if the compression goes up when you test afterwards; otherwise it's either HG, ex or intake valves. The leak down helps you determine more from there by listening to where the leaking air is coming from.
Again just do one thing at a time, it's easy to digest that way and record your results. If your unsure of what to do after you inspect everything chime back in.UNDER CONSTRUCTION - 24v 325e (future DD), DD 525i
stripped out e30 rally project - in progress
M50NV -> M50TU E34 swap underway
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trouble shooting began last night. I took out my coil packs (which are all brand new oem). 4 out of 6 cylinders were filled with oil.. took plugs out, they were all shot. these plugs have less than 3k miles on em. replaced valve cover and tube seals. put new plugs in, what plugs do you guys recommend for m50b25? i used ngk 6962.. maf has been replaced with one from my e34 m50b25. didnt stall once connected, but ran real rough. Debating on whether or not im gonna replace the pigtail for it. i do not believe my head is cracked, however she does eat through antifreeze. Need to do a compression test just dont have the means to do it right now. Could someone help me understand how the cel is supposed to be hooked up during the swap? maybe i can get in there and rewire some things. i will get some pictures once weather permits....Comment
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Clarify for me.
Last night you replaced the valve cover because the spark plug housings were filled with oil (4 of 6). Cleaned the coil pack boots(rubber tubes that connect to spark plugs) and restarted with no change in the way it runs? Is that why you want to compression test now? Its good to test compression but if it runs fine now no need.
You replaced MAF? It needed a new one last we spoke; If it runs rougher with the MAF connected than disconnected it needs a new one.
Also I think you grabbed the wrong spark plugs for an M50NV. 2 prong, but don't go 4 prong try these:
I've no clue about the CEl lightUNDER CONSTRUCTION - 24v 325e (future DD), DD 525i
stripped out e30 rally project - in progress
M50NV -> M50TU E34 swap underway
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no change in the way it runs, correct. Yes, i replaced the maf. previous maf would allow car to run, but once i put it in gear and started to drive, it would stall. with the new maf, it runs, and when i put it in gear, it still goes, shakes real bad, jerks back and forth, and just overall runs rough. I used the bosch two prongs previously, she didnt like them to much. i also tried the bosch four prong, again didnt like them one bit. have only really had luck with ngks.Comment
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Vaccuum lines all checked?
What did you do with o2?
Do you have a harbor freight around they have super cheap compression guagesUNDER CONSTRUCTION - 24v 325e (future DD), DD 525i
stripped out e30 rally project - in progress
M50NV -> M50TU E34 swap underway
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