Engine not quite running right, need some suggestions

[88325is]

Hey guys,

I picked up the s52 swapped e30 yesterday. Car got me all the way back to Virginia Beach from PA without and significant problems.

One of the things that sucked though was the heater would only work when the car was idling at slow speeds, at higher speeds (highway cruising) it didn't work and with the 40 degree temp last night it sucked.

Before Mike sold the car to me he was trying to fix the temp guage because it wasn't reading correctly. According to the temp guage the car runs very cold the whole time (stays in blue) and based upon the heat I would say thats pretty accurate. Mike replaced the Thermostat but it didn't solve the problem.

Something I noticed is that when ever I accelerate I smell coolant coming in through the vents and this is when the heat is semi-working. Could there be something wrong with the water pump? Or maybe the cooling system was just bled incorrectly... I'm not sure what the cause is so if any of you have any ideas please shoot them my way.

Oh also, supposedly this car is missing a few groundstraps on the coil packs, I believe its cylinders 1 and 6. Would this be causing the rough part throttle acceleration or is that because of the coolant system problems?

Thanks,
Jeff

[matt]

Grounds for the coils are not critical.

The heat issue is a bubble in the heater core. You're going to need to replace it...

[88325is]

Ah, I was hoping that wasn't going to be it.


If its just a bubble though, can it just be bled out?

[matt]

Not if there's a leak, it'll be back.

[88325is]

The car has 215k miles on it so it probably is time to replace it :)

Thanks for the help Matt.

[Jason89i]

before you go replacing the heater core.....

flip-flop the coolant lines at the fire wall. if you only get heat when its idling, and goes cold above 2k rpms, then you have the heater lines backwards. they are a real bugger to remove, but it can be done without intake removal.

re: smelling coolant, then yes the heater core is on its way out......but its not uncommon.

re: cool temp. if you have the 80deg euro thermostat in there (like you should), the car will rarely go above the 1/4 mark.....but you probabily cant pass emissions. if its the 88deg u.s. thermo, then is probabily stuck open.

hope this helps.

[BlackE30]

Tried to start the car up this morning and it took 10 minutes. Its running very rough. The spark plugs were just replaced yesterday before I picked up the car...

[88325is]

I took the car out today for a drive and it kept dieing on me when the car was shifted into neutral, it would try to stabilize the revs but die instead. I'm guessing its going to need new plugs again but I can't figure out why its running so rough. Can't keep buying 60$ worth of new plugs every other day. Any ideas let me know.

Thanks

[mattdk318i]

sounds like a nightmare...i shall keep my mouth shut this time. Last time i told you it was a NV M50 lol.

Hope you get it sorted out.

[matt]

Vacuum leak is probably the most likely thing. Or a clogged ICV.

[1990m3]

I was just about to say vacuum leak is likely as well. Check all your fittings very carefully and your hoses for cracks. This could be a $2 repair

[BlackE30]

I checked the plugs today and they looked good. The car drives pretty good once its been driving for about 10 minutes. No stalling problems, its just when its cold (if I push the pedal down to the floor its dies) I can only lightly blip the throttle to keep it running.

The car hesitates ALOT under acceleration when its still warming up.

question about the water temp sensor wire- is it the one towards the front of the engine or the one towards the rear? I unplugged both to see if I could get a CEL but didnt get anything. I'm guessing the CEL doesnt work correctly because I also unplugged the Throttle position sensor and the car still ran fine and nothing flashed up.

Anyone know which wire is the cel wire in a 413 ECU, Red Label?

Thanks!

[Jason89i]

it sounds like the temp sender (ecu one) is not functioning properly. i had the same thing happen with my m50b32.....except it was the exact opposite. plug didnt make contact and the dme read that the car was always cold......ran really rich. i had a local mechanic scan the car (gt1 while it was running) and saw the engine temp was 0degC....obviously wrong. wiggle connector, dme said engine was now 82degC. he easily found the connector for the dme temp sender was not good.

not sure how your car got wired. obd2 uses a dual temp sender.....one temp signal for the gauge, one temp signal for the dme. all neatly wrapped into one unit. however, when installing the motor into an e30, you need to use the e30 gauge temp sender. (drill/tap head for sender, cut one wire off the dual temp plug / install on e30 sender.) most people leave the dual temp sender in, but only use it for the dme temp signal. i would double check all his temp sender wiring.

or...go have the dealer scan it. they can see all the inputs while the car is running.

cheers, jason

question about the water temp sensor wire- is it the one towards the front of the engine or the one towards the rear?
!

update: the dual temp sender (4 wire plug) is closest to the radiator. the e30 gauge temp sender (single ....or double) wire is closest to the fire wall.

I I unplugged both to see if I could get a CEL but didnt get anything. I'm guessing the CEL doesnt work correctly because I also unplugged the Throttle position sensor and the car still ran fine and nothing flashed up.
!

unplugging these will NOT throw a check engine light. unplugging the dual temp (or dme temp sender) will cause the dme to think the engine is REALLY cold. unplugging the e30gauge sender will cause the temp gauge to stop working. unplugging the tps will not cause the check engine light to go off....(it will throw a soft code a scanner can pick up though).

[TwistyTunedE30]

Since blacke30 is my room mate i got to go and pick up this sick little ride, aside from the hesitation its great. My first thought was airbubble in the system keeping the heater from working aswell as richening it, but i guess these motors dont need a bleeding system. The thing is i bought a m20b25 325i "drift car" intake, free flowing exhaust , jim c chip and 4.10lsd, and we did a stop light pull and i stayed dead even with him, he may have pulled a tad, but he should have atleast 125-150 more bhp then i doo.....we shall see tomorrow when it gets scanned
-Max

[matt]

He should have 50-70 more HP than you. That should be good for about 6 lengths by 120.