new to me, 98 M3
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How does the car feel now? Is it that you are just chasing the check engine light or is it actually not running well?
Car feels like it's running fine. But something is clearly tripping the CEL. There's just one weird slight dip in rpm coming out of gear into neutral at stop sign. doesn't stall or anything and recovers quick. perhaps vacuum leak still? I just didn't have enough butt time in the car to know if that was normal. I'm taking in for a real smoke test tomorrow just to verify finally one way or another its not a vac leak.
Other signs seem to point to it running rich. High STFT numbers, Gas mileage is about 18-19 mpg when driving pretty easily (ie not laying into supercharger) I would think that could be better, black carbon buildup in exhaust. Car does have highflow cats though.
Lets say the DME and fuel trims worked their way down to those low negative numbers over time -8.6% LTFT and peaks above -20% STFT. I'm wondering if all the "buttoning" up that I've done changed how the car would be reading those and tripping the CEL. I guess I can clear them and see if it return closer to 0's.
I'll probably wait to do that until after the smoke test.
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yes, both 02 sensors are new (pre cat) I was throwing the CEL before I changed those.
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Gotcha. I would attribute this to some sort of vacuum leak. My coupe also drops idle and comes back when thrown into neutral at stop signs on occasion.
Yeah, at this point I'm hoping it's that. Should hopefully find out tomorrow with the smoke test. If they don't find anything I think I'm going to have to pull the valve cover and make sure my CAMs are still perpendicular from my vanos job. That's really the only other thing I can think of which could have been just a degree or two wrong that I haven't checked.
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Update after smoke test. Smoke test showed smoke. One point on intake boot elbow. Previous owner did some weird gluing thing to allow for the asc delete and tried to glue the extra nipple thing needed together with the stock elbow. I had previously discovered this one on my own and tried to jb weld the crap out of it. Honestly surprised it still leaked. Gonna order one of these bad boys and be done with it.
Second area is on the supercharger body. Not a part where there's a gasket to fix. I'll get a picture later. Tech and I agreed the only fix will be to try some RTV sealant and hope it holds. This was a much smaller leak.
Leaks seemed small to me but he claimed these would definitely be big enough on any car to trip the CEL. So, I'll hope it's that.
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I know you said you JB welded that boot really well but do yourself a favor and replace the boot if it's been torn at all. This may or may not be your issue but the boot is already weak if it's torn where you could see it.
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Where did you go for the smoke test? I've been looking to do the same thing, but haven't really been sure where to go or how much it'd cost.
McDermotts Service and Repair - 6525 Seybold Rd, Madison - 608-274-8288 Cost $114 with tax for the test. I have to find a way to make my own tester next time
test takes about 15 mins to do. Trick is keeping the oil burning. I'll come up with some sort of DIY eventually. PatsBimmer - yes, new boot is on order, should be here Sunday. Unfortunately I still don't think this is the problem. Last night I RTV sealed the Sh&t out of the old one and plugged the small gap on the SC. Granted it could still be leaking, but i'd be surprised if it was. I put like 1/4" of sealant around the thing because I didn't care what it looked like. Cleared codes, rest adaptions and they came back. Guess I'll know one way or the other when the new one gets here.
This brings me back to my vanos job. As I mentioned one of my CAM locking tools slipped while doing the job. If one of the CAMs is off just a little bit could that cause this problem? If so, how do I verify and how do I reset timing? Would I need to pull the Vanos and re-lock the CAMs flush after that's out?
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This brings me back to my vanos job. As I mentioned one of my CAM locking tools slipped while doing the job. If one of the CAMs is off just a little bit could that cause this problem? If so, how do I verify and how do I reset timing? Would I need to pull the Vanos and re-lock the CAMs flush after that's out?
I've pulled apart motors that were running well with one of the cams being a tooth or so off correct timing. I wouldn't be too concerned about your work, especially if you were using cam locks.
For reference I never use the locking plates, and can get timing spot on first go.
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Ive never used any of the "special tools" the m52 in my 328i was a tooth off on the intake cam when disassembling and I was trying to figure out for awhile when reassembling why none of my marks were lining up.
You can take the valve cover off and turn the engine over until the cams are pointing at each other, at a 45* angle and make sure the locking block slides on and sits flat.
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Thanks guys, i plan to confirm timing in a few days if needed. Here are some strange happenings from over the weekend. Before the smoke test I was throwing codes of the following:
Mixture Deviation Bank 1, Lambda regulation Bank 1, Cat Efficiency Bank 1 and 2, misfire cylinder 5
I got a new intake boot to fix that smoke leak and rtv'd the SC where needed, confirmed no more leaks in those spots. I moved spark plug from 5 to 2 and coil pack from 5 to 3 to see if that misfire followed. Cleared codes and reset adaptions.
Now I get totally different codes attached, so maybe I'm making progress? I google for Aux Air Injection system and can't find anything. Only thing I find refers to the Secondary Air Pump system, in reading those threads that appears to throw it's own code, so I'm not sure if they're one in the same. Most of those threads are for e46 and new cars. I can't find anything e36 specific on this. Anyone ever seen that code?
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It still has the air pump?
Yes, is that not normal?
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I didn't know with all of the other mods. Have you checked anything on it to see if it actually works? It has been a while since I worked on one but I think it only runs for a period of time when the engine is cold so the first thing to do would be to figure out what the correct sequence of operation and see if it is functioning. Maybe you already did this and I missed it.
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well, no real update on the m3. Still the CEL but drives fine. Been driving the e30 convertible lately.
Came out of the office to this today. Anyone have a spare m20 oil pan?!? My damn luck...........
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Hows it going?
It was a pretty small crack, only a millimeter or so wide and about half inch long. So, I just JB welded it and been driving it now for a couple weeks. So far so good. Time to buy a skid plate. Good thing I fixed this because 2 days later the M3 master cylinder broke so now that car is out of commission! Ugh, never ends
Hopefully will be fixing that today and tomorrow.
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