Engine rattle around 1,500 rpm under load

[detach8]

Folks, I notice my 6 month old car engine has a soft rattling noise around 1,500 rpm under load. Is it the engine running too lean? I have a performance issue too -- I notice the car performs WORSE when the engine warms up. But I thought that was a sign of running rich.

I do have air scoops and volker plugs. Not sure if any of that makes a difference.

--

Update: I have removed my scoops since the start of this topic but it was not the cause. This has been resolved by a tranny adaptation reset, please see page 4:
http://www.bmw-sg.com/forums/engine...ine-rattle-around-1-500-rpm-under-load-4.html

 

[tomace]

Re: Engine rattle around 1,500 rpm under load

Folks, I notice my 6 month old car engine has a soft rattling noise around 1,500 rpm under load. Is it the engine running too lean? I have a performance issue too -- I notice the car performs WORSE when the engine warms up. But I thought that was a sign of running rich.

I do have air scoops and volker plugs. Not sure if any of that makes a difference.

detach8, hows yur driving patten from day one? From what I know, the more I wack, the better it is.. (in terms of FC or performance)

 

[wt_know]

Re: Engine rattle around 1,500 rpm under load

whack solve most problems

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

Well I pussy foot it nowadays since it is lacking power, i might as well trade for fuel economy. and no shit, i can get an extra 1km/l if i just pussy foot it.

My blood pressure lower also.

Anyway just got my ride w/ the BMW performance exos today and it is DAMN SHIOK. u just feel like revving the car. my FC drop from 9.4 to 8.4.

BUT... still no power :S

 

[wt_know]

Re: Engine rattle around 1,500 rpm under load

is the engine rattle problem solved?
what do Munich said about the rattle issue? just whack it with the newly installed performance exhaust and all problems will go away?

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

well they said they cleared some carbon deposits when they were installing my exhaust (i was like huh???) and SA said he didn't hear the sound after they did that. he's checking with BMW Asia for software upgrades and will contact me if there's any.

anyway, i take the words from my SA with a pinch of salt. they aren't the actual guys in the workshop so i just want to know the end result - fixed or not? well... oddly after the performance exhaust install i can't hear a shit coming from the front. it's probably still there, but not that obvious anymore ya...

i have removed my air scoop and somewhat it did improve my power. instead of cold = good, warm = sucks, now it's cold = sucks, warm = normal. the engine stays warm more often than cold so that makes more sense for me. maybe it was blasting my engine with too much air it ran lean when warm? or maybe the exhaust affected how it performs? no idea really

but for sure the air scoop did help my pre-LCI 320i. not so sure about LCI -- maybe BMW did tweak the ECU quite a bit.

 

[tomace]

Re: Engine rattle around 1,500 rpm under load

Maybe drive it (50 / 50) wack / pussy for a while and monitor it 1st..

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

Still sucks. Due to the performance exos the rattles are less obvious but still there. I hooked up a generic OBD II... no trouble codes, but I clicked "Clear" anyway. And i'm going to do the throttle adaptation reset (whether it works or not, I dunno, just gonna do it anyway)

Long term fuel trim is around 1.5% means engine is compensating by running rich. I'm tempted to put the scoops back in after a few runs and datalogging.

Still waiting for MA to tell me if I need a software update.

Tomace... ai test drive mai?

 

[tomace]

Re: Engine rattle around 1,500 rpm under load

Still sucks. Due to the performance exos the rattles are less obvious but still there. I hooked up a generic OBD II... no trouble codes, but I clicked "Clear" anyway. And i'm going to do the throttle adaptation reset (whether it works or not, I dunno, just gonna do it anyway)

Long term fuel trim is around 1.5% means engine is compensating by running rich. I'm tempted to put the scoops back in after a few runs and datalogging.

Still waiting for MA to tell me if I need a software update.

Tomace... ai test drive mai?

hope all goes well ~~

Cheers ~~

*can contact me @ 90493989

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

Hooked up my OBD-II tool for these 2 days. Found out that the car was running unusually cool (coolant temp

 

[tomace]

Re: Engine rattle around 1,500 rpm under load

Hooked up my OBD-II tool for these 2 days. Found out that the car was running unusually cool (coolant temp

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

Nah I am quite confident of my butt dyno on my old ride. The new one just doesn't perform right.

In fact I did get o2 sensor readout from 2 other cars (a Merc and a Volvo) and both had lower average O2 sensor voltages (approx 0.5-0.6) even post cat, so I am quite sure my E90 LCI is running rich for some weird reason. I'm going to send this diagnosis to MA and see what they can do. Maybe something as simple as an ECU reset would resolve.

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

I'll post updates of this at the other thread:

Stock engine runs O2 sensor voltage ~0.7+ volts?! Very rich? - BMW-SG - The BMW Singapore Community

 

[douggie]

Re: Engine rattle around 1,500 rpm under load

What RON fuel are you running?

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

nothing less than 98.
i occasionally pump v-power and caltex platanium.
it does not sound like knocking if thats what you're wondering
although ignition timing can go as high as 45-50 degrees during light acceleration

 

[douggie]

Re: Engine rattle around 1,500 rpm under load

nothing less than 98.
i occasionally pump v-power and caltex platanium.
it does not sound like knocking if thats what you're wondering
although ignition timing can go as high as 45-50 degrees during light acceleration

Yeah, then maybe it is not knocking. But if the timing is advanced that much during light acceleration, it might be at the verge of knocking and when the load comes in (up slopes), the timing does not retard fast enough? I guess it has to do with the ECU tuning that BMW did for the LCI (to meet Euro emissions)?

That is why the others saying to "whack it" actually makes sense!

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

How to whack in SG haiz...

I have a rare opportunity to go to Airport or go West to East like this morning to drop wife off at Tampines (I stay in Bt Panjang)

Even then, can't whack much. At gear 3, 4,000 rpm + already exceed speed limit. Keep getting off throttle.

Once I get off throttle, fuel injection cut, engine load is zero, oxygen sensor reading is zero.

 

[wt_know]

Re: Engine rattle around 1,500 rpm under load

when enter expressway, slow down abit, then whack to rpm 5k for 0-100, shiok

How to whack in SG haiz...

I have a rare opportunity to go to Airport or go West to East like this morning to drop wife off at Tampines (I stay in Bt Panjang)

Even then, can't whack much. At gear 3, 4,000 rpm + already exceed speed limit. Keep getting off throttle.

Once I get off throttle, fuel injection cut, engine load is zero, oxygen sensor reading is zero.

 

[detach8]

Re: Engine rattle around 1,500 rpm under load

i thought short burst of acceleration is not good for the engine

 

[douggie]

Re: Engine rattle around 1,500 rpm under load

Just need to whack enough to keep RPMs above 1,500 when moving off from stationary