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Old 03-20-2019, 04:45 PM   #1
e30_jake
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Question Somewhat New E30 Owner (First post)

I have owned a 1991 318i Cabriolet for 1 year now, as a daily driver. And I have been looking around forums and other websites that could help me out with a few problems and questions I have. I've been looking to do some slight modifications, ( I have already gotten bigger brakes put on) but for now I was wondering if anyone could give me some tips on what I should do before I really dive in, either to make my driving experience more pleasurable or to improve the life of the car. I am the 4th owner and it currently sits at 179,XXX miles with just about stock/OEM parts all around aside from the spark wires and brakes. Any feedback or tips helps.
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Old 03-21-2019, 10:54 AM   #2
roguetoaster
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Fun: Good tires, Bilsteins/H&R sports, maybe an E36 rack, M3 rubber LCABs, maybe an exhaust if you're in to that, and maybe a stereo overhaul.

Serious: Overhaul the timing chain setup, be warned, it's expensive, rebuild the AFM, check compression, do the mess under the intake.

Other than that, assess what is broken or on the way out and fix it. Listen to the car, be a sympathetic owner and don't be afraid to redline the car every time you drive it.
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Old 03-21-2019, 06:19 PM   #3
e30_jake
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I'm looking to get some new wheels and tires this spring/summer, I've heard about the E36 M3 Rack and Z3 rack, which I still need to get some more info on before I full send on one of those. I've got Bilstein HDs in the back, but I do need some new shocks in the front though. As far as the timing chain and AFM, I wouldn't quite know where to start. What exactly do you mean by "the mess under the intake."? And for the redline, I think i banged off the rev limiter once leaving my high school parking lot, and I've never done it since. Redline on the M42B18 is 6400 I believe, which I usually try to stay away from, (I shift around 6000 when I'm really giving her the beans.) But it's been healthy really ever since. Thanks for the feedback btw, its really appreciated.
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Old 03-21-2019, 08:14 PM   #4
bmwman91
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The timing case rebuild is a huge job, and definitely not something that should be done as a first (or second, or third) wrenching adventure. The timing assembly is sort of the main weak point in the E30 M42 engine, and although catastrophic failures are statistically rare, they do happen (I know because it got me). You CAN easily replace the timing chain tensioner piston without really taking much apart, and it is not too expensive a part either. Part #17 (and #18 is a good idea):
http://www.realoem.com/bmw/enUS/show...diagId=11_4367

Anyway, if the car does not make any diesel-engine sounds at any time (loud clacking that varies with RPM) then chances are things are OK. If at some point you think you want to rebuild the timing case, you can swap in a 1994-1995 E36 M42 timing case and associated gasket. It is a better design that eliminates the main failure point in the E30 M42.



The AFM (air flow meter) may or may not need cleaning/rebuilding. If it runs smoothly then you are fine.



The "mess under the intake" is the elimination of the throttle plate de-icing system and the mess of coolant lines involved in that. It is a "nice to have" thing, but not really necessary, and if you live somewhere cold it might be a bad idea.



Don't be shy about revving the dog shit out of the thing. 6400RPM is no big deal (assuming that the timing assembly is in good condition). I drove my original 220K mile M42 like a bastard, revving it to 7200RPM all the time thanks to an aftermarket chip. Granted, it did ultimately die thanks to a timing case failure, but that was going to happen at some point anyway.
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Old 03-22-2019, 07:25 AM   #5
e30_jake
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Okay great, good to know I'm able to start beating up on it a bit more haha. As for as the timing chain, I don't recall problems with varying rpms other than a little after I had got it. At "idle" (which does vary sometimes, but usually around 1000) it would go up and down, kind of bobbing, but that was the late winter last year and it hasn't done it since. I will check out the AFM, and as for the de-icing system, I think I'll keep that given it's pretty much spring now, and temps are still around 30-45 F. I will definitely keep the timing chain in mind though, if it goes on me, honestly I'd like to do somewhat of a rebuild of the engine, just to get some other things buttoned up while its apart/out. The rebuild would just be to refresh the engine, but maybe some performance stuff would be cool. I understand though a couple of your posts explain one of the best ways for better performance is just a M20 flywheel and Chip, which I would definitely like to do. Thanks for the feedback.
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Old 03-22-2019, 11:27 AM   #6
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Sounds good. If you look into a chip, my recommendation is Sssquid Tuning. They probably have the best M42 tune on the market, along with what may be the best understanding of Motronic 1.7 (the ECU in our cars) of any of the tuners out there right now.
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Old 03-22-2019, 02:41 PM   #7
e30_jake
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Alright awesome, thanks for your help. I just had one more question for now, on my way to school this morning, (after I had let the car warm up) I tried to take it to 7000. Once I reached 6400 ish, I'm not quite sure where I was, it seemed as if the car let off even though my foot was still on the floor. I understand that the car might still have some programming to keep the engine from hitting redline too hard. Honestly for a second I thought I had thrown a rod, but it obviously didn't and still runs fine. I really want to take it there I'm just scared to
break it.
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Old 03-22-2019, 02:50 PM   #8
bmwman91
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Nah, the stock programming in the ECU limits the RPM. It does this by cutting fuel injection as far as I know. It only saves you from over-revving it via the gas pedal though...if you were to accidentally downshift from 5th to 2nd (instead of 4th), there's nothing preventing it from mechanically spinning fast enough to fail catastrophically. "Throwing a r3v" is always a recipe for a bad time lol.

On a stock M42, there is not too much point in going past 6400RPM anyway. It has already peaked in power output at that point. When I was around your age (yeah I have been driving one of these for a looooong time) I didn't care, and I revved it to 7200 all the time with the chip because it was simply more fun. I did autocross a bit, and there were times where it was faster to finish a straight section with the engine bouncing off of the limiter rather than shifting into 3rd and back into 2nd, but mostly I just liked beating the snot out of the car. I worked like 3 jobs in high school to pay for the car, so I was all about having fun in it. Granted, this was around the year 2000 and the car had a lot less miles on it than yours probably does, so I don't necessarily recommend driving it like you want to kill it.

Also, a 7200RPM redline lets you hit 60MPH in 2nd gear. Around 2000 was when The Fast and the Furious came out, so all of the idiot high schoolers (myself very much included in that category) were all about those 0-60 times lol.
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Old 03-22-2019, 05:35 PM   #9
e30_jake
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Yeah, I understand that it's useless to bang it off the limiter but it's pretty cool and fun to do lol. But it's still good to know that if I do it, the engine won't blow up.
Thanks for the help though, I really appreciate it.
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Old 03-24-2019, 04:31 AM   #10
econti
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First thing I do is to pull the intake completely, change the plastic coolant flange pipe, and tidy up the mess of vacuum lines and delete the throttle body heater. Also gives you a chance to remove carbon buildup and paint the manifold as they usually look like shit.
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