Z3

[inconsistent]

Hello, newbie to the forum,
First, thank you to all those who have helped with info over the many years. I joined on this day and I am grateful for the many posts I have read for helpful info. I drive a 2000 bmw z3 m52tub25, highly modified. So, I bought the car as a salvaged because it had been rear ended otherwise I would not have done any mods, originality is always best in my opinion. Here is some things ive done. Bought another 2.5 and pulled original motor out, 280000 miles is why. The new motor had about 68000, came with the 5 speed. I went through the whole motor with original bmw gaskets and seals. Rebuilt the vanos myself. Removed all emissions and installed an m50 manifold. Installed headers and ran dual exhaust with high flow cats and x pipe, with borrila cuffs on both sides of the rear, removed battery compartment. I never done this kind of work however forums such as these and YouTube was the key to my success. I had active autowerkes run me a tune via online. Put in a larger radiator and electric fan. New coilovers with a subtle drop. Rewrapped the interior with full grain black leather. Removed all the plastic wood and replaced with real wood and tiger veneer covered in a sun resistant two part epoxy. Deleted secondary air pump and ran a catch can in place using larg hoses. There are some things I done im sure im forgetting, oh, new bmw rotors and brakes paired with anthracite bbs 16 inch rims along with 17mm spacers that are to darn expensive but we're highly recommended. The first time I tried starting she fired right up and I left her alone. Just changed the oil using only bmw oil. Changed all the fluids using redline. She ran great taking her on 400 mile trips to see dad before he passed and around town during the summer. I live in Colorado, snow. There were times she seemed to have less power but still responded well, other times she had an enormous amount of power and have left a couple of young bucks subarus saying holy smoke where's the turbo. However, there were times this thing would just start missing like crazy, mainly at stop lights in which I would just turn her off and restart and she would be ok. Other times it would happen while cruising and again, switch the ignition off and restart she was fine. About a week ago she really started missing and I would give it more gas and she would straighten out giving me more power than usual. This went on for a few days and turning the ignition off and restart would fix it some times. Now, she is missing all the time and im stuck. She runs still and will drive with a sound as if the exhaust was plugged up. Now power no matter how much gas I give. Check engine light is on because I deleted the secondary air pump. Ran the diagnostic, cheap one, and it says a miss on cylinders 23 and 4. Im using original o2 sensor but deleted the post o2 sensor with the tune from active autowerkes. As I said, she always started instantly and ran very good. She still starts instantly but sounds like a clogged engine. Throttle still acts normal. I used the original coil packs that came with new engine. I've went through the air intact with some good cleaner in the throttle body, ICV, and maf. Didn't help but throttle was more responsive. I refuse to take it to shops because I think 180 an hour is to damn much. If you have some ideas they would be appreciated. I put in highly recommended four prong plugs about 6000 miles ago. Oil is very clean. Please share your thoughts and I will take them seriously and then follow-up. Could it be head gasket even though oil is clean? Will 3 bmw coil packs go out at the same time. Oh, I had the bmw injectors rebuilt when I installed the engine but had words with the guy because he took 4 weeks to do it, could he have sabotaged? Should the o2 sensor make her miss in 3 cylinders and not the others. Im 51 years old meaning im a little experienced in mechanical theories. If you could help, believe me, its greatly appreciated.

 

[Shelly]

 

[Shelly]

What a great 1st post
Very interesting

 

[inconsistent]

What a great 1st post
Very interesting

Thanks, could have added more but didn't want to over do it, lol.

 

[Smudgemanuk]

As an m52tub28 owner I will try and help you as best I can. Firstly congratulations on the amount of work you have undertaken, good stuff, your car will be thanking you!

Secondly,
I can confirm the secondary air pump delete will not put on an engine light on as I have done it myself. I put some sealant on the bit of metal covering the hole to ensure no vacuum leaks.

If I was head gasket I am sure you would see it in either the oil or the coolant. If it was head gasket you would most likely be consuming coolant or oil, and lots of it. Other symptoms can include white smoke (coolant) or blue smoke (oil) on startup. If it isn't consuming (disappearing with no apparent leaks) either of those fluids you can probably rest your fears.

I am still running on 1998 original coil packs on 114,000 miles

Someone correct me if I'm wrong but I would try swapping the coil packs around to see if the issue moves with them.
I know either the camshaft or crankshaft position sensors are prone to failure (I think one normally fails more often than the other, someone will correct me)
I would also try (if you haven't already) replacing the fuel filter, you kinda of might as well for a few quid.

Here is a resource I made that might help you with parts buying: (it's meant for uk but might work in us)

Technical - Part Buying Guide For Newbies

Hi all, welcome. I thought I would make a part buying guide for people new to the forum, as I found it quite daunting for the first few weeks of owning my z Step 1 - Finding part numbers The first thing I do when buying a part is find the...

zroadster.org

Hope this helps
Chris

 

[inconsistent]

Thank you good man,
No smoke, and oil is clean. She starts, idles, and still drives but no power and sounds like a bad running lawn mower. I drove around today for a bit and she goes up hills with no problem. However, if you give it more gas she just doesn't accelerate. I thought about the coils but wonder if 2, 3, and 4 would go bad at the same time? I still have me other engine wrapped up with the injectors and coil packs. Will swap out this coming weekend. This car purred without skipping a beat and always accelerated increasing as the rpm exceeded 3500. I think the m50 manifold compliments this. My plans: get some fresh bmw oil just to treat her a bit. Remove the manifold and injectors with the fuel rail. Inspect then just order new seals from bmw, d shaped. I personally created the adapter plate for the throttle body as you may know they don't match, therefore 2 new seals will go there. The manifold has the oval shape butted to the d shap on the block. Im thinking this might be an issue over time. They make a heat plate that is made for BMW racing. Its about 1/2 inch thick with oval cutouts. Im thinking of contacting the maker and see if I can have one made with a d shap graduation to oval so the seals will match both sides, just a thought. Im thinking my o2 sensor has gone bad???? Like I said it would run bad, then turn key off, restart then was good. I truly love this car, I mean I love this car so im down in the dumps about her. As I go through her I will post my experience. Just waiting on me parts. Your response is greatly appreciated and im eager to have others join me in my journey as this is the first time ive had problems.

 

[Pond]

It could be a VANOS issue. If the VANOS isn't operating correctly, apparently it can behave like a misfire, as the timing goes all over the place on acceleration.
You say you rebuilt it, but it could still be playing up.

Another simple check is make sure you have a good earth across the coil packs. I forgot to tighten one of my earth posts on the head and after a few days it sounded like a bag of nails.

 

[inconsistent]

That's a good idea to check ground. When I replaced the engine, the old engine ground ( pink) was in bad shape so instead of buying a pink ground I bought a battery ground cable and used that. That would explain alot. My alpine I bought which I grounded to the rear trunk frame would cutout when I cranked the Scorpions, lol. I forgot all about that. Also, I bought a complete front end kit, tie rods, A arms, bushings etc... and installed while the engine was out. When I got her running, I took her to an import shop to have an alignment, the jokers didn't get alignment right, broke my air bag wire in the steering, pulled my door card handle off and scratched the underneath of the front bumper. They also drove it, the vanos needed 300 miles for break in and im more than sure they nodded it out. This means my vanos could have been compromised. I will start with the ground then move to the o2 sensor. Thanks for the information. I wonder how to check if the vanos is good. Before I rebuilt the vanos sounded like marbles. Today there is no sound but the seals could have gone bad.

 

[Mint]

Hi and to the forum from me too in Stafford. Good luck with sorting out your problem.

 

[inconsistent]

Hello, good to meet you. I've got her torn down and waiting for parts. Not sure what is exactly wrong. However, new seals for the intake manifold, throttle body, and injectors won't hurt.