View Full Version : So i finally got my motor together then... crap

Brent 86 325es
03-02-2007, 08:36 PM
So after almost a year i finally got my 2.7i in the car and working good. I probally have put about 15 miles on it when im accelerating from a stop sign. Hit about 5000 rpms and shift. I didn't notice anything till i stopped accelerating at about 45 mps. The car seemed a little rougher then normal. Sure enough when i stopped at the next stop sign it was idling at about 100-200 rpms lower then normal. And much rougher... Scared the crap out of me. I was almost home so i drove it gently home the last half mile at about 40 miles per hour. I noticed when i was accellerating that there was dead spots in the acceleration. The power curve was all messed up. Now what scares the crap out of me is the fact that the car used to do this before the motor was rebuild. Back when it had bad rings. So right now im pretty scared... Could i have damaged the rings somehow? Or could it be something else? i didn't notice any sound when it happend... Just started idling rougher and the messed up power band. Acceleration wasn't smooth. My other thought is i suppose it could be the head gasket? ](*,) ](*,) ](*,)

03-02-2007, 08:42 PM
are you still using the same harness and ecu that you had in the old motor?

Brent 86 325es
03-02-2007, 08:46 PM
no i have the 173 and 'i' harness. Complete 'i' top end. Its weird cause i had it at 5k rpms a couple times before and it was fine. I just put in new spark plugs, breather tube, and coolent temp sensor today.. Kinda doubt those messed it up. My muffler is totally shot. So there is not much back pressure. Could this mess up the valves to the point of loosing compression?

Brent 86 325es
03-02-2007, 09:19 PM
just talked to the guy who did the machine work on my motor and he said that a valve probally went out of adjustment. Sound like the problem to you guys? He wasn't a bmw specialist just an engine builder. So i was wondering what you guys think. Thanks

03-02-2007, 09:28 PM
should have filled it with oil first :/

03-02-2007, 11:13 PM
just talked to the guy who did the machine work on my motor and he said that a valve probally went out of adjustment. Sound like the problem to you guys? He wasn't a bmw specialist just an engine builder. So i was wondering what you guys think. Thanks

Have him take a look at it BMW m20 motors are really nothing special that a motor builder wouldn't be able to figure it out.
I think if a valve went out of ajustment you would hear some ticking and clacking coming from the cam cover.

at only 15miles you should be taking it easy on that motor till it is broken in.

Brent 86 325es
03-03-2007, 12:45 AM
I just checked the oil. It was fine. There was some pretty loud ticking. They were out of adjustment to begin with so i didn't notice a huge differance. But it is noticably louder. I never thought about that. Thanks

03-03-2007, 04:56 AM
(*,) ](*,) ](*,)

Well if you are going 45 miles per second of course you are going to need another rebuild.
Check your coolant, maybe it's a one way leak and it's only going into the coolant. I would say ignition is the culprit. Check your grounds and then for traces on your distributor. Alot of shit is forgoten when you wait a year before putting things back together. Hope this helps.

03-04-2007, 04:27 AM
sounds like air intake leaking to me.

or bad fuel.
cannot rule out the basics on something that spans 2 separate motors

03-04-2007, 05:39 AM
There are a number of things that could be causing this.

Check your AFM.
Pull the plugs and see if they look good.
Check for spark.
Check fuel pressure to see if it is low.
Look at the distributor cap to see if it's okay.
Check for any vacuum leaks.
Check the fuel filter too, could be very dirty from old gas.

03-04-2007, 10:07 PM
I really hate to say this but could be the timing belt was off a little and the pistons hit the valves and bent some. Take out all your spark plugs, look for damage and do a compression check. Take the valve cover off and look for broken rockers. Make sure your belt has tension and tensioner is set properly.
If all these things check out ok then it's something minor.

Brent 86 325es
03-08-2007, 01:31 PM
So here is the truth... Or what I know of it. Two of the valves wern't opening... one intake and and one exaust. The eccentrics (maybe?) slipped and something else happend... i don't fully understand the tecnical terms involved with the rockers/lifters/ valves in an m20. Anyway it runs like a beauty now. Very smooth and wow.. i love e30s. Well for the most part.. my battery isn't charging. So rather then start a new thread i was wondering if anyone could answer a couple questions real quick for me.

So i would guess its the alternator.. but one.. i still have the 325e alt, thats only 80 volt right? But should work anyway... also how many wires go to the back of your 325i alt? I have two, near the bottom. If you have more would you tell me where to? Also could anything other then the alt cause this poblem? Assuming everything is hooked up right. Thanks

03-08-2007, 04:41 PM
Do you have a multi-meter to measure voltage? You need to measure the voltage of your battery with the car off - it should be 12 volts. You should then measure the voltage of the battery with the car running and no accesories on - it should be 14 volts. Then turn on many of your accessories like headlights, heater fan, defrost, etc and measure the voltage of the battery again - it should stay at or very near 14 volts. If the battery drops way below 14 volts when the car is running then the problem is your alternator.

(and your alternator would be 80 amps not 80 volts ;) )