e34 engine performance

[Faiz]

Hi allMost cars incl my present e34 seem to have the problem of slipping in and out of tune. Usually you can tell from the first one or two km in the morning. If the engine is smoooth and relatively quiet when you first drive the car in the day, the condition tends to last most of the day. I noticed it with my udm until something else also happened recently. I had the mf battery replaced (din 66 from AAM - nothing else was done) and presto the engine was sweet and pickup 'syrupy' for a couple of days! After that things went back to normal re: above. Just thought I'd share this. What do you guys think happened? Cheers, Faiz

 

[535i]

Yup .. it happens to me ...

Sometimes, the car is just plain smooth ..
In some other day, suck mannnn ..
The engine is not responsive, suspension tends to float .. damn .. I hate those days ...

I told my mechanics about it .. They said ' Itu perasaan je bang ... '

Problem still not solved .... for the last 9 yrs !

 

[Faiz]

So it's not my 'perasaan' only. But the change in performance because of the new battery is something new for me.
Rgs, Faiz

 

[flash]

Hai ya, just like people, our cars also got their on and off days. In my case, my babe merajuk more than give me pleasure...

 

[magicfox]

it could be just me... but i 'feel' that my e34 runs smoother if i warm up the car in the morning.. or before the first drive of the day... even if i start the car in the afternoon and weather is steaming hot outside...

just my feeling... :huh:

 

[bimmerman]

My UDM is better to drive on cool days and a real pain in the behind during hot days. But i'm sure we all know why already. Hot days less oxygen for combustion mah. But strangely it also drives quiter on rainy days compared to hot days. Not just the engine but road noise and suspension noise as well.

 

[Bmmad318i]

Cold days air is much denser, hot days less dense.....

 

[xtracooljustin]

Originally posted by magicfox@Feb 25 2005, 03:34 AM
it could be just me... but i 'feel' that my e34 runs smoother if i warm up the car in the morning.. or before the first drive of the day... even if i start the car in the afternoon and weather is steaming hot outside...

just my feeling... :huh:

agree wif u...

if i dun warm up my car in da morning... it 'll jerk like hell in first n second gear if i dun press da accelerator... sometimes can even mati engine so easy...

but once pass da blue zone on da temp gauge, its all better n nice to drive

 

[erica34]

Originally posted by bimmerman@Feb 25 2005, 05:40 PM
... But strangely it also drives quiter on rainy days compared to hot days. Not just the engine but road noise and suspension noise as well.

ya man - dem strange! mine also less road noise and suspension noise when it's raining...

 

[Lionel_Koh]

According to mine mech,the bimmer engine work in high temp...that why the temp meter always stay at the half. That why if u don't warm up the car first,u feel that the car is not responsive. However if the engine is hot enough, the car will more responsive. Can't overcome it, the only solution is to warm the car each time when u start up ur babe...like me, at least 3-5 min.

 

[st8six]

fuiyoo..!!
So glad i stumbled upon this topic.!!
I thought I was going nuts as I always wondered why my e34 is so well behaved some days and absolutely terrible to drive sometimes...?
Now confirmed I am not going crazy!! And this definitely not 'perasaan' only.
I have never warmed up my engine before taking off in the morning, guess I would have to try that out.
My e34 definitely drives better when the weather is cool though...?
hmmm... doesn't this contradict the 'warming up' theory?
And i enjoy driving my car at night more than day time wor...?

Help!!
I am going nuts again...!!
Or maybe 'perasaan' only...?

 

[pussy]

actually, the e34 needs to be pampered or some TLC everyday.

also, at least once a week must do this:

- wallop to red line all the way i.e. to klia and back in top speed
- fill up v-power and pakai tanpa ekonomi 'in mind'
- wash engine every other weekend
- wash under car every other weekend

then your car wil be fine..

 

[flash]

Originally posted by erica34+Feb 26 2005, 07:13 AM-->QUOTE (erica34 @ Feb 26 2005, 07:13 AM)

 

[flash]

Originally posted by pussy@Feb 27 2005, 07:58 PM
actually, the e34 needs to be pampered or some TLC everyday.

also, at least once a week must do this:

- wallop to red line all the way i.e. to klia and back in top speed
- fill up v-power and pakai tanpa ekonomi 'in mind'
- wash engine every other weekend
- wash under car every other weekend

then your car wil be fine..

True, true, once in a while kena hentam our BMWs kao kao.... The following day, she will drive like a dream.

By the way, is this how you treat 535i too? ** cabut **

 

[Faiz]

Well, this is getting 'interestinger and interestinger'...just look at the coaxing and 'petua' for a fit and willing udm: alternate TLC and whacking all the way to the redline, warming up the engine, driving in cool weather, etc!

I also noticed something else recently. After a change of battery, a friend said that I should use Shell V-Power for more power AND fuel economy. Well, I tried. And know what - better power output but poorer fc! so of course, smoother power means heavier itchy foot on accel. pedal? BTW what is the best octane rating for udm engines?

Rrgds, Faiz

 

[bimmerman]

Another reason I can think of why the car is quiter on cool days. During cooler days your crank driven engine fan is mostly off so you don't get that whooshing sound caused by the fan when you accelerate. On hot days it's whoosh-whoosh at every start stop so your car sounds like it's trying very hard and the extra air resistance saps power too. Electric fan conversion anyone? :dunno:

 

[Faiz]

Originally posted by bimmerman@Feb 28 2005, 04:49 AM
Another reason I can think of why the car is quiter on cool days. During cooler days your crank driven engine fan is mostly off so you don't get that whooshing sound caused by the fan when you accelerate. On hot days it's whoosh-whoosh at every start stop so your car sounds like it's trying very hard and the extra air resistance saps power too. Electric fan conversion anyone? :dunno:

Hi bimmerman

And the vanos gearing system? the whirring noise at about the front of the engine seems to be louder during hot days/times than cool. Anyways the engine is definitely noisier and somewhat sluggish stop-start traffic. Yeah, an electric fan might just be part of the answer. A cost estimate for the 'upgrade'?

faiz

 

[bimmerman]

Originally posted by Faiz+Feb 28 2005, 06:46 PM-->QUOTE (Faiz @ Feb 28 2005, 06:46 PM)

 

[ehoe]

Just wondering anyone know how the clutch driven fan works?. I know its directly attached to the engine and it has a clutch that activates the fan. How does the fan clutch know when to engage?. Is there a sensor or something? I was told the fan clutch is actually filled with oil, perhaps that has something to do with it activcating. Any experts out there care to explain how it works?.

My fan clutch kicks in quite often (well maybe coz its new) and engine is significantly noisier (whoosh sound) and performance is reduced too due to the higher resistance. On really hot days you can really feel the huge difference in performance when the fan clutch is on and off.

 

[Faiz]

Originally posted by bimmerman@Mar 1 2005, 12:57 AM
faiz

Hey Bro, could you please describe in detail how the Vanos gearing system sounds like? I have this 1 second long rickety-tick noise like tappet noise on hot days which occurs around 1,800-2,200 RPM only. Could that be the Vanos noise you've mentioned.

As for the electric fan conversion, there are pros and cons which i've read somewhere but can't remember. I'd like to know too..... [/quote]
OK, let me see if I get this right. I seem to make out three ttypes of sound/noise other than the engine - there is the noise from the air-con compressor coming on, the cooling fan engaging as the engine gets hot and the regular whirring noise from the front (like a chain running across gears - it's a chain that runs the vanos mechanism right?). Now the tappet-like noise is just that, the tappets thgat need adjusting? Well, I'm no expert, just what I think I'm hearing. Cheers.

Faiz