[VladPC]

Hello everybody. Fist of all I just want to salute you all and thank you for a tone of info that I gathered throughout the time because of this beautiful and very helpful community.

Now...let's get straight to the point.

I am a happy-ish owner of a european model BMW 335d and the problem that it has is related to the small turbo not making any boost. I can hear it spooling up but nothing until 3000rpm when the big one kicks in.

Yes, I know...check the vacuum hoses, check the pressure converters, dpf or egr valve (not my case because I have both egr and dpf deleted ; also no swirl flaps).

I have DIS and ISTA+ on my laptop and I have activated all of the actuators and seem very fine...they move on command.

Also I took it to a garage and asked the mechanic to check the actuators by hand. Unfortunately he checked the by mouth , by taking off the vacuum hoses and sucking in the air. The result was good, the actuators held vacuum.

The only problem is the intercooler. Is either broken or cracked or something because it's leaking oil...a good ammount actually.

Now my question is....does the intercooler have anything to do with the fact that the small turbo is not making any pressure in the system? Is it really that small that all of the pressure it creates, it just escapes at the cracked intercooler?


If this is the case, why does the big turbo kick in very hard, or let's say, as it should? Souldn't the boost created also leak because of the broken intercooler?

[dmanb2b]

Originally Posted by VladPC

Now my question is....does the intercooler have anything to do with the fact that the small turbo is not making any pressure in the system? Is it really that small that all of the pressure it creates, it just escapes at the cracked intercooler?


If this is the case, why does the big turbo kick in very hard, or let's say, as it should? Souldn't the boost created also leak because of the broken intercooler?

Whether this is your problem or not, you should replace the seals and eliminate boost leak as a cause. It certainly doesn't help. If you do have a significant boost leak, it should show up with black soot coming out of exhaust if the dpf is deleted.

[nicklockard]

Yup, I'm in the same boat. Just replaced motor mounts, all vacuum hoses, valve cover gasket. Added a CP3R90 HPFP. Have deletes and upgraded intercooler on a JR2.8 tune. Small turbo won't work at all. Car is gutless until 2500 rpm's. This thing should be a freaking rocket, but it's embarrassingly slow instead. Making 277hp.

None of the mechanics around here know how to work on them. It's too freaking hot (120F) to do extended diagnostics in the garage trying to figure out what obscure thing might be wrong. Vacuum system checks out perfectly fine. WTF. These cars are so finicky it hurts.

[VladPC]

Originally Posted by dmanb2b

Whether this is your problem or not, you should replace the seals and eliminate boost leak as a cause. It certainly doesn't help. If you do have a significant boost leak, it should show up with black soot coming out of exhaust if the dpf is deleted.

It acutally does smoke some a bit to a lot I would say. If I put my foot down at 3000 rpm in 3rd or 4th and so on it smokes quite a bit. I can see the black some behind me.

I also tried to brake boost and when I do that it smokes so heavy that I can't even see behind me because of the black soot.

[dixy2k]

Any CEL?
Intercooler leak would be my first guess. You could also have carbon build up.
Have someone check it out for you.

Having some oil in the intercooler is normal.

[dixy2k]

maybe this helps too

https://www.e90post.com/forums/showthread.php?t=1515245

[AlpineX]

no faults on the DDE at all? seems unlikely.

[dmanb2b]

Originally Posted by AlpineX

no faults on the DDE at all? seems unlikely.

depends on tune

[335dsleeper]

N75 valve under the rear pressure converter. It’s clipped to the lower heat sheild just above the DPF or delete pipe.

11747810831

[AlpineX]

Originally Posted by dmanb2b

depends on tune

If that's the case, I would be focusing on the errors you know. sounds like a leaky charge pipe or ccv could be giving you metering errors. The small turbo is going to spin even if the bypass is open so you could look at actuation there.

[VladPC]

The car was sent to a garage some time ago where it had the swirl flaps deleted and the egr delete software. The mechanic said it had the passenger side engine mount broken (thus loosing vacuum ; now the engine mount has been replaced and still no change), the intercooler cracked from one side to the next and also the boost hose cracked.

Before the car went to the garage it had the following errors on DIS ( the pic with 4530 error, oxygen concentration implausible too low, and something about rail pressure too low, pozitive control deviation too low)

After the mechanic deleted the egr and swirl flaps it showed something else on the scanner ( maf sensor, intake air temp sensor and o2 sensor with and again the o2 sensor fault with too low concentration ). The 4530 error and the rail preasure error dissapeared. He said the car had a vaccum leak on one of the vac lines going to the swirl flaps which he fixed when he deleted them...

Carbon build up should not be the case, the intake ports look fine.

The boost hose was washed in the pic. It has collected oil around it like that in about 20-30 miles. It was waay more covered in oil before the wash.

Regarding the maf error, before he had done the tune, the maf error never appeared. I read something about it's normal to get the maf error since I have deleted the egr in the software because the maf calculates the opening of the egr valve and since there is nothing for the maf to see it's normal to display an error... Now I don't know anything about that intake air temp sensor. It didn't show any errors before the car went to the garage. That pic was taken by the mechanic and didn't say the sensors had a fault...so maby is normal.

Anyway I have ordered a intercooler and hopefully I will get it installed at the end of this week (stock nissens intercooler) together with the new upgraded siliconic boost hose. We'll see then...

[335dsleeper]

Bad MAF can put the car in limp stopping the HP turbo from spooling.

If your intercooler is cracked and boost hose leaking, why would you get boost from the LP turbo?

[VladPC]

This is the question why I have started this topic in the first place.

As I said before the car has felt the same even before and after the MAF error... I haven't plugged in the scanner for some time. It could just be an error because the mechanic switched the ignition on with the MAF unplugged. His laptop screen is too small to see if the DIS memorized the error with "currently present" or "currently not present".

[bmwdiesel]

Originally Posted by nicklockard

WTF. These cars are so finicky it hurts.

u cannot be more right. 35d vacuum/turbos/boost system is so fragile, that once you fix one thing, the other will show up in next few months with similar symptoms (reduced power)
mechanic told me that he has these 35d engines often in the yard sitting for a month as they can't diagnose it, so owners give up and drive it that way....

i don't have any tune as you, since I am battling reduced power all the time and each time it's something else.

so, if you want something more dependent, it's advisable to change the brand, or at least the engine (smaller displacement, means more reliability with BMW)....even tho, I heard latest BMW's are even more failure prone, as it looks nice from outside, but BMW is using more and more cheaper components for their engines, since they are not concentrating on sale numbers, but cost cutting and profit. since mercedes overcame them in sales and audi will soon....

even in germany, ford mustang is more popular than BMW 4 series with younger crowd looking for some sporty coupe and it's much more bang for buck.
yes bmw will continues to be premium german sporty drive, but there is more and more disgruntled owners with reliability.

[VladPC]

Just replaced the intercooler with a new, stock one and honestly is the same thing. The boost hoses do not leak, everything is and looks like new. It feels like there is absolutely no boost under 2000 rpm, from 2000 to 2700 pulls liniar and at about 3000 rpm all hell brakes loose. It feels more aggressive though after the new intercooler has been installed. But still nothing untill 2000 rpm.

If I set the transmission to manual M3 or M4 and I try to make a pull from 1100 rpm to 5000 rpm starting from 40 or 50 km/h it does not make any boost untill 2000 and something rpm.

[dmanb2b]

Originally Posted by bmwdiesel

u cannot be more right. 35d vacuum/turbos/boost system is so fragile, that once you fix one thing, the other will show up in next few months with similar symptoms (reduced power)
mechanic told me that he has these 35d engines often in the yard sitting for a month as they can't diagnose it, so owners give up and drive it that way....

i don't have any tune as you, since I am battling reduced power all the time and each time it's something else.

so, if you want something more dependent, it's advisable to change the brand, or at least the engine (smaller displacement, means more reliability with BMW)....even tho, I heard latest BMW's are even more failure prone, as it looks nice from outside, but BMW is using more and more cheaper components for their engines, since they are not concentrating on sale numbers, but cost cutting and profit. since mercedes overcame them in sales and audi will soon....

even in germany, ford mustang is more popular than BMW 4 series with younger crowd looking for some sporty coupe and it's much more bang for buck.
yes bmw will continues to be premium german sporty drive, but there is more and more disgruntled owners with reliability.

Need to find a better mechanic and parts. Replace intercooler with ATM, all vacuum lines and the harmonic balancer, run fuel cleaner and change oil regulary, the M57 is pretty darn reliable. Those unfamiliar with working on cars, yes a honda may suit them better.

[VladPC]

I'll try to reset the adaptations on the dme these days...maby the dme memorized some parameters and that's why it does not pull from low down...who knows. If I'll reset the adaptations on the dme, do I have to rewrite the throttle pedal or anything else or is it just a simple click as "clear error memory" ?

[Owen81]

Why are you looking everywhere except the issue everyone has suggested already? Its a vacuum issue. If you have tested and or replaced everything related to the vacuum system (mounts, lines, converters, reservoir etc.) then the problem is likely your small turbo. There is not going to be any "one click" fix, just put some time in testing your system.

[bmwdiesel]

did you also change EGR pressure converter on the right side below the intake manifold? if not, I would be surely looking there. mechanic swore at me it would never fail and if it would throw a code, and guess what, after I changed that the power returned for couple of weeks, before I lost boost elsewhere....never ending story

[VladPC]

The egr is deleted and the vacuum nipple has been blocked by a blanking cap.

It is not a vacuum issue because I have checked everything regarding vacuum (hoses, pressure converters, actuators, I even have footage of the actuators move using DIS software and they move perfect)

It just feels like it's not accelerating liniar and hard from down low. It feels just like you have to wait for the preasurized air to enter the engine, you floor it and wait for the boost to build up. Everything above 3000 rpm is just chaos, traction control lights almost permanently on second and third gear because of tire squeal.

I'll try to take a look at the MAP sensor. I have read on another forum some guy with a 535d e60 had the same problem. He changed absolutely everything even bought two new turbos (new pressure converters, vacuum hoses, new compressor bypass actuator, new intercooler, new boost hoses) and still nothing. Then he cleaned or replaced the MAP sensor and solved the problem.

[bmwdiesel]

well, someone had the same issue and it turned out to be injectors...

[Owen81]

Do you have boost logs?