M52B20 Unconventional Issues - Help Needed if possible

[vangelov]

M52B20. Symptoms:
Valve ticking once hot when engine returns to Idle after revving or light ticking at 1500-2000 range when constant. Changed Vanos seals /pretty bad/ with Beisan. Got extra spring and added the alignment ring Beisan sells. No much of a change. Rattling still there.
Engine started to randomly smoke. Especially after deceleration with the engine. Also, when accelerating full throttle I get some smoke. Changed PCV with OEM - no change. Was told cylinders are ok compression wise. After a long stay - no smoke.
Recently started to unexpectedly stall. Not only would cut-off but after restarting it will work irregularly till I shut down the engine and start again. Then works fine. These started to happen more and more often. RPM needle would jump. Strange after such a "jump" /feels like I shutdown the engine for a sec/ I see smoke coming from the back. Changed Crank and Camshaft sensors.
At this point I am clueless. No issues on INPA except sporadic MAF errors.
Was thinking to bypass PCV for testing but not sure what would be safest way. Also, I suspect higher vacuum on the oil cap to be some of the oil sucking reasons /whats normal reading?/.
When cold engine is much more responsive, silent and powerful. Once I reach normal temp I lose power, hear the lifters and see the smoke... What beats me is that smoke is really random! I may accelerate twice once there will be once will not be.
I would really appreciate any clue or a guide... Oil I used was Castrol 10w40, Total 10w40, Fuchs 5w40, Selenia 10w40 etc.

[Eric93se]

MAF errors, find a used good MAFS.

Definitely add a PCV oil catch system, they are cheap and worth it.

Your oil weight selection is good.

You can remove all your lifters and disassemble them clean them, there are youtube guides on how to do it, you can get a cheap ultrasonic cleaner on ebay too, it's not a little job but may be worth doing. You can then put new valve stem seals.

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When your oil gets old you can try running an oil flush, just make sure you do it on a fully cold engine (sitting over night). Have you ever done the valve cover gasket? it can sometimes tell you a lot.

[Gearbox88m]

I need to find it again, but I read that the M52B20 had an issue with the lining of the cylinders and using Ethanol fuel would eat through the coating.

As far as the ticking, I think it is your lifters,and they possibly need to be rebuilt or cleaned.

[ultimatetester]

I need to find it again, but I read that the M52B20 had an issue with the lining of the cylinders and using Ethanol fuel would eat through the coating.

As far as the ticking, I think it is your lifters,and they possibly need to be rebuilt or cleaned.

In Bulgaria the fuel does not cause this problem. Only the USA has this kind of fuel which is the reason the USA has a different M52 block. Its sulfur by the way


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[vangelov]

Thank you all.

Would MAF relate to the stalling issue? Valves will be cleaned again. I still have INPA errors on crank and cam sensors despite replacements. Someone mentioned earthing.
PCV I would isolate. I guess it wont hurt for a short time. However, can someone tell what is the pressure reading on the oil cap idle/under load. I know has to be negative, but have not seen any actual readings for reference.
I suspect that the negative pressure builds up and engine starts to suck oil from the oil stick. I found oil in the intake manifold. Quite a lot...
Also, I suspect an exhaust gasket leakage /not much but audible under load/ I believe this could be adding to the enriched fuel situation. Can someone share how could I test the exhaust pipes and their leakage if any besides sound coming out.
I suspect I have no CAT rather just an empty unit...

[Eric93se]

Modify the PCV system to add an oil catch system, so that the manifold doesn't suck oil vapor.

http://www.ebay.com/itm/Universal-Si...-/171012398919

It's possible to have bad brand new cam/crank sensor, people try to buy OEM only like Siemens brand.

[vangelov]

So, to recap:

My main concern is the smoke and how to bypass the PCV. I tend to think as a short option and rule out or not the PCV valve just putting the cam breather outlet straight into the PCV hole of the intake manifold. This is an quick and easy option. Other option would be close the intake PCV hole, close the dipstick opening that goes to PCV and let the fumes go in the air for couple of hours.

[vangelov]

Hi again All!
I am resurrecting my old topic as I am still finding issues that are quire weird. Now I am facing the famous "injector ticking" sound but only when the car goes up to the operating temperature and started after. If the car gets to the normal temperature and I never shut it off it is just fine. The problem does present only if I start the car in operating temperature. It loses power, smells like gasoline and I get the really annoying "ticking" sound. The errors are related to the valve shaft sensor (most of it) some for crankshaft and MAF sensor again. I replaced the camshaft sensor with a VDO one - same result. Suspected the wires being brittle, however they prove good. swapping back to the old sensor did fix the issue for couple of starts and I am back to worst. One thing to note is that problem appeared gradually. It was time to time, then more often till now is every second start pretty much. I am pulling hair as I am not willing to buy anymore parts w/o at least a clue where to look ... Could it be the Valve shafts not aligned? I have the vanos sound well pronounced too despite my rebuild ? I just need to start from somewhere yet not really willing to shoot blind so any help would be appreciated...
Many thanks!

[B320i]

Loss of power, reeks of petrol, ticking noise... Your car is in limp mode ("Limited Operating Strategy"), the loud ticking noise are the fuel injectors "batch firing." The cause is one (or more) of the sensors feeding the DME bad values, and it is substituting some figure, to protect the engine until the issue is resolved.

You need to use GENUINE BMW sensors (yes they cost a lot, shop around). There are numerous stories on this forum where posters have used non-genuine sensors and it's caused no end of trouble, when a genuine sensor would have solved the problem in the first instance. VDO are supposed to be a BMW supplier - but in all honesty, plenty of these supposed "BMW OE equipment suppliers" have been known to churn out crap from time to time.

You also need to investigate the Coolant Temperature Sensor, I'm not sure if the 95 and onwards 320s use the same sensors as the 325/328i from this period, if they do, you'll be able to find some resistance figures to check with a multimeter. If not, you have to observe the following: the test is checking the resistance of the sensor changes in a linear fashion as the engine (and thus the coolant temperature) warms up. If it jumps to infinity or goes open loop, you have the source (or part of it) for your problem.
It almost sounds like the heat from the engine when shut down causes the sensor to reach a point where it no longer functions. If the car sits for say, 30-60mins and you restart, is the problem there, does it appear after a few minutes, or not at all? To eliminate or confirm this sensor being the cause of some troubles, do you have any issues starting the car when hot or cold, does it sputter, need a lot of cranking, or need several cranks before something happens?

Disconnecting the MAF shouldn't change how the engine operates, it might behave a bit funny without that data but it certainly won't become undrivable. You can try operating with it disconnected briefly to see if this makes any pronounced change in operation. If it improves, you know that may also be a source of trouble.

[vangelov]

Hi and thanks for your comprehensive response!
It has been a saga indeed with these sensors. I have replaced the crank (was told original) and camshaft (I purchased VDO from ebay member with 99.9 % good ratings). Honestly it worked at some point and then stopped. Now, I don's see the jumping RPM dial when trying to start the car and it won't for many many times. When the car is at rest for more than 30 mins or so, it starts fine. When I get the temp gauge on 11 o'clock is good. The moment I get ti 12 and start again I am going into the limp. I had only couple of episodes where I could not start the car at all. I have alot of camshaft errors on INPA very few still on crank and MAF though. Regarding the temp, INPA does read more or less correctly and is withing the range and what I see on the instrument panel pretty much is the same. What bugs me is that the issue gradually appeared to worsen. From once a month to once a week, day and now is constant... May an original (not sure anymore) CPS fail after few mths? May my DME be at fault? Would somewhere be a brittle cable insulation and there is a electrical leak (if it was the case I would think this may be an issue no matter if cold or hot car?).

So to recap the issues in short: Car starts cold fine, runs fine till normal temp till I shutdown. If I start less than say 30 mins I always get the ticking noise. Had just once a case I almost drained my battery cranking and would not start. I let it rest for 5 mins and started.
Many thanks again!

[Thomas525]

Modify the PCV system to add an oil catch system, so that the manifold doesn't suck oil vapor.http://www.ebay.com/itm/Universal-Si...-/171012398919It's possible to have bad brand new cam/crank sensor, people try to buy OEM only like Siemens brand.

Does the M52 engine have an oil separator ?

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And if it does - then why do you need a separate catch can system ?

[Thomas525]

OP, a solvent flush will likely not help your lifter issue. The dirt is usually too baked in. But you can try - its dirt cheap and doesn't take long and is very simple. At your next oil change, on a hot engine (which makes sludge softer and thus easier to remove) add one litre yes one litre of diesel to your crankcase and run it at IDLE ALONE for 15-20 minutes. Then stop and drain the oil and diesel and put in the new oil and filter. Don't worry about getting every drop of diesel out, it will vapourise and get out through the ccv system during driving. It will clean out your entire engine.

Another alternative to reduce noise would be to simple use thicker oil.

Rebuilding your lifters properly will not be a quick job since you have 24 to deal with and it is time consuming to dissasemble and clean out. Strongly suggest you just purchase a set of rebuilt ones, and install them, then rebuild your old set at leisure and resell those. Rebuilt ones are not expensive at all.

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You need to use GENUINE BMW sensors (yes they cost a lot, shop around). There are numerous stories on this forum where posters have used non-genuine sensors and it's caused no end of trouble, when a genuine sensor would have solved the problem in the first instance. VDO are supposed to be a BMW supplier - but in all honesty, plenty of these supposed "BMW OE equipment suppliers" have been known to churn out crap from time to time.

VDO is an oem manufacturer for BMW, for decades.

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Other oem manufacturers for BMW - lemforder, bosch, vdo, castrol, zf, siemens, cochline, hella, behr........

[B320i]

VDO is an oem manufacturer for BMW, for decades.

Other oem manufacturers for BMW - lemforder, bosch, vdo, castrol, zf, siemens, cochline, hella, behr........

Like I say, completely agree these are OE equipment makers, and in theory there shouldn't be an issue. Trouble is, in keeping a watchful eye on threads regarding cars with running faults, the folks that buy the non-genuine sensors often have recurring problems. I recall one thread that dragged on for a long time while one or two members argued a cheap sensor would be just as good as OE... Another where someone tried several aftermarket sensors made by "OE Suppliers" and ALL were dead-on-arrival, a genuine sensor solved his problem.

The fact that his issue was never really cured by a sensor change, and this new VDO part is throwing error codes tends to affirm what I've just said.
As for the crank sensor, was this a used part? Or a new "genuine" part that didn't come in packaging with BMW part numbers?

I'd forgotten the M52 combined the two coolant temperature sensors. If the diagnostics and gauge cluster read normal, then this can probably be excluded.
For the most part, your car is starting and running, no strange RPM readout jumps, non-start conditions. The codes you have suggest the crank sensor could warrant further investigation down the track. Given the occasional hot-start difficulty, the engine entering limp mode once warmed up and numerous Camshaft-sensor codes, I'd say you have a defective Camshaft sensor. New parts can be bad out of the box (like I said, there have been a few threads in the last few years where this happened).

My last bit of advice, is to clear all the fault codes you have now. Disconnect the battery for a few hours so the ECU is reset and has to relearn the optimal values. Then reconnect it and take the car for a drive, allowing it to warm up, fast and slow driving, and shutting down & restarting (do this close to home). See how the car behaves now, and check what fault codes are logged after this.

Can anyone confirm or deny what I've just written? Am I on the right track given what the OP is reporting to us? Really don't want have them throwing parts at a problem because of my advice.

[Thomas525]

Even original i.e. propeller stamped parts have been known to be bad out of the box.

OP, to reset codes, use the stop test or unplug your dme and key2 your key in the ignition for a few minutes to bleed off all the capacitors. Then plug it back. Don't need a few hours with this stuff.

You have a tricky cam sensor but you should not have starting trouble because of it. Unplug the cam sensor and drive that way for a few days. The crank sensor alone is sufficient for ignition timing.

[ultimatetester]

Does the M52 engine have an oil separator ?

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And if it does - then why do you need a separate catch can system ?

It does have it. But the output air goes to the intake manifold (and the separated oil should go to the dipstick) If this part gets clogged, then the manifold will suck in oil.

Personally I’ve never seen this happen and even if it does I don’t think this has anything to do with the problem.

[Thomas525]

Yes, i know it does. I was being rhetorical, in reaction to wrong and unnecessary advice. OP, your oil separator can be cleaned out. There are youtube videos on it. And even without an oil separator, most engines did not consume a ton of oil anyway fwiw.

[vangelov]

so I sent my feedback to the ebay seller (who has 900000 reviews) and NO response on my complaint! Oh well... I guess either they care not ... or acknowledge the units they sell are going bad... either way not professional for an US based seller... I will certainly buy next from Amazon! Anyway... here is the second time I read I can run the car with disconnected CPS, however what I am expecting to witness as a behavior? As per the codes, they are fairly constant errors coming pretty much the same way every time. I guess for now I will go one step at a time, change the CPS again with one from a more reputable seller or Amazon... Perhaps even buy a new crank sensor? One thing I noticed with this car is that (guess unrelated) was that injectors are from 0280150714 vs those originally used 0280150415 for M52. Not sure if this could make much of a difference as they have almost similar specs so I am stumbled why non original were used ?!... I know also the engine runs much better than a stock 320i too... So I lean towards dealing with remapped stroker. Again, I don't believe this makes any difference with the situation currently I have as the engine was running just fine for the last few years...

[B320i]

You have a tricky cam sensor but you should not have starting trouble because of it. Unplug the cam sensor and drive that way for a few days. The crank sensor alone is sufficient for ignition timing.

If we know the Camshaft sensor is bad, why are we suggesting to unplug it? Whether the DME receives garbage data or no data at all, it will still set a fault code and will probably still run in limp mode as a fail-safe measure.

As per the codes, they are fairly constant errors coming pretty much the same way every time. I guess for now I will go one step at a time, change the CPS again with one from a more reputable seller or Amazon...

Never mind who sells it, so long as it is the genuine part. Obviously shop around as some outlets (for example the ENTIRETY of Australia...) price gouge on a lot parts for these BMWs, and quite unnecessarily, IMO.

[Thomas525]

The dme is dumb enough to not realise that that a tricky sensor is being tricky. That's why we unplug it, because then it ignores that sensor entirely for sure.

[B320i]

The dme is dumb enough to not realise that that a tricky sensor is being tricky. That's why we unplug it, because then it ignores that sensor entirely for sure.

Good point, thanks for clarifying!

With the Cam sensor unplugged, the engine will still be in fail-safe mode, correct? Or is it possible it will be more drivable?

[Thomas525]

There is no limp or fail safe mode for the engine. There is one for the transmission. The engine only needs the crank sensor signal to run everything decently. All the other sensors are there just to fine tune the fuel air mixture for optimal fuel economy and optimal power, that's all.

Nothing that is unplugged will improve the engine's performance, EXCEPT when what you are unplugging is a damaged sensor. So my comments above were in the context of diagnosing and isolating a bad sensor. And when you unplug a bad sensor, of course the engine will seem better, for obvious reasons.

[vangelov]

Hi all!
So finally I got a new sensor - VDO again. Short lived glory though ... After a week or so with a nice an smooth ride I am back at the starting position. The darn ticking noise is back and I am again sad and upset.
Only clue that comes my head is that Cams have moved a bit after my alignment I did like 3 years ago without alignment tool. I lean towards that scenario but wanted to check with more experienced people who know more than me if I should go that way and open the valve cover to check that theory...

[Eric93se]

Common problem for people who don't do the VANOS rebuild properly.

Run injector cleaner, get an actual OEM BMW cam sensor.

[vangelov]

I realized that after couple of "incidents" the Sensor now does work fine. Would that be a clue to say my fourth sensor is bad? Only difference from before was that I had the oil below the minimum on the stick - say like a liter needed to get it back to the minimum - sadly BMW has no warning light to say low oil. Anyway, since I filled it to the specs, I have no bad readings. Now, do I need to clear the errors (would clearing help?) Do I also need to zero the adaptations? I went to the MOT a week ago and was told my CO2 readings are quite high. It makes sense if the sensor would be still bad, however at the test was okay (at least ticking went off). They suspected a bad lambda but my INPA does not show they are abnormal? I am stumbled again as to where and what to look ...

[bobinoha]

Hey, I am having start issues with my m50b25 and the cause is probably also Crank sensor. I was searching around the internet and our forums in the Czech Republic and there are a lot of people having problems with brand new sensors. The important thing is that the new sensor must have BMW logo and must be ordered directly from BMW dealership (part nb from RealOEM and order at dealer). Only this means, that it is OEM genuine part. It is common that even OEM manufacturers (VDO, Siemens, Bosch, Sachs, ZF, ...) make parts in different quality levels which are later sorted in two categories - OEM BMW parts, and aftermarket parts (they often only grind off the BMW badge). Most of the time it is not worth buying everything at dealership (bushing, mounts, shock, ...), but everything regarding DME sensors should be genuine! I was just thinking, this could help you if you did not know it yet.