e46 330Ci low rev power problem - advice needed!

[lee330]

Hi all,

Newbie here, I have been reading the forum and am hoping for some advice on the low rev power problems I am having with my recently purchased e46 330Ci.

When test driving the car I thought the low down power was poor but the guy at the garage assured me this was the power delivery curve on the 330Ci, after some research on this site it appears this is not the case. This is my first BMW after driving a diesel Golf GTTDI, the power delivery on the Golf was all at the low end so I thought the BMW could be the same in reverse. Out of interest, how is the power delivery of other peoples 330’s on this forum?

I am struggling to find any real power under 4k revs, on pushing the accelerator the engine livens up but nothing really happens, i generally have to shift down a gear and get the revs high enough for it to accelerate with any grunt, above 4k however the acceleration is strong.

I took the car to a BMW specialist and he fully scanned the car, the only fault code was for the thermostat that needs changing, he has checked the VANOS, MAF Sensor and Cam position sensors all of which are working fine and within parameters.

Once the codes had been cleared the car does feel like a little livelier at the bottom end, but not where I believe it should be.

Can anyone give me any pointers as to what could be causing the problem? The car is under warranty for 3 months so I would like to get the problem resolved asap.

I also don’t know if the spark plugs have been changed, the car is on 78k so do you think this would help?

Thanks in advance

Lee

[330southampton]

Well with the 330 you wont get all power til around 3500rpm anyway, so it could just be your not used to it? but unless driving it i wouldn't be able to tell. Try getting it on a Dyno ( £35ish) and get a print out so you can see if theres a problem with the power delivery, if you get a print out ill email you mine and you can compare? mine ran spot on, on 3 runs.

[Jobbo]

Go and drive another one - or have you already compared it to another?

[lee330]

Hi Jobbo, I dont know anyone with a 330 but I will try and test drive one that is for sale locally. Will be useful to do the comparison

[330southampton]

Lee are u close to southampton?

[lee330]

In in Brighton, not a million miles away but still pretty far, it would be difficult to get over there unfortunately

[road_rager]

the power on the 330i is pretty linear, so I would guess something is wrong, def test another one just to be sure!

[Smike]

Should have decent low-end performance to be honest. They're reasonably torquey
New plugs and air filter certainly won't do any harm, check your cyclone valve and pipework as if that's gunged up it won't help. Check for air leaks after the MAF ( not sure how old your car is and your hoses are cracking yet ).
As said, check it against another if poss

[ANOpax]

Don't worry.

The power delivery on the E46 330ci will be very different from what you're used to with the golf TDi.

There will be much less torque which is why it feels sluggish to you. My 330ci behaves exactly as you describe and only comes on song above 3,500rpm - exactly the point at which my 3.0d is running out of puff.

My rule of thumb for overtaking is that you need to be in 3rd gear if you're rolling at less than 60mph. In my diesel, 4th gear is sufficient.

From what you describe, your car is fine. No harm in getting it dyno'd though since you're still under warranty (whatever the warranty is worth).

[330southampton]

There isn't "much less torque"? the Gttdi has 320nm, 330s have 300nm. Theres not enough to notice unless you mean the torque of the Diesel kicks in lower down?

[Spudler]

Well worth chucking a tin of this in the tank... http://cgi.ebay.co.uk/Cataclean-Catalytic-Converto...

[ANOpax]

330southampton said:

There isn't "much less torque"? the Gttdi has 320nm, 330s have 300nm. Theres not enough to notice unless you mean the torque of the Diesel kicks in lower down?

That's exactly what I mean.
Golf torque maxes out at 1900rpm
BMW torque maxes out at 3500rpm and even when it does, it's 6% less than the Golf

Apologies for not being clear.

Edited by ANOpax on Saturday 19th February 10:17

Edited by ANOpax on Saturday 19th February 10:22

[bluetone]

I don't know if yours has a problem or not but these cars are fairly heavy and you do need to give the motor some revs to get the best out of it.

[rich85uk]

i find mine to have plenty of low down grunt(right from the word go) but below 4k rpm i find the engine ideal for lazy driving and might appear abit sluggish compared to a high powered diesel engine.

to give you an example was driving from aylesbury to luton airport via the back roads when i met an a5 3.0v6 tdi that wasnt hanging about. if i kept my car below 4k i couldnt keep up, above 4k i had the advantage.

perhaps you just abit used to turbo diesel power delivery. if you dont have access to another 330ci then perhaps you could find a local straight fast road/dual carriageway where you will be able to accelerate hard from a standstill to about 80mph but dont launch with the revs increased. the car should accelerate strongly and 60mph should come in at 6.5 secs, and 100mph will crop up fairly quickly. watch a few videos of e46 330 in car acceleration to get a feel if yours appears similar.

not the most technical method but a very easy one

[ANOpax]

bluetone said:

I don't know if yours has a problem or not but these cars are fairly heavy and you do need to give the motor some revs to get the best out of it.

Good point.

Depending on which Golf Tdi you had, the kerb weight of the 330ci will be 50-100kgs heavier than your golf.

[330southampton]

Also remeber the 330 has Alot more Horse power and still has more power to weight ratio that a golf gttdi. The 330 should just feel quick all the time, and make the golf feel really slow.

[ANOpax]

330southampton said:

Also remeber the 330 has Alot more Horse power and still has more power to weight ratio that a golf gttdi. The 330 should just feel quick all the time, and make the golf feel really slow.

Er, not true below 4,000rpm. Up to 3,500rpm the Golf has more torque AND more power. And it's a lighter car. Basically, the golf has better power and torque/weight than the 330 does right up until 4,000rpm. After that, it's game over for the golf...

Golf Dyno Chart (150HP version)


330ci Dyno Chart



It's no wonder that people upgrading from fast diesel hatches are wondering why their BMWs are broken...

Edited by ANOpax on Monday 21st February 15:34

[330southampton]

You realise the golf weighs almost the same as the bmw right?

Golf-1451kg
Bmw-1505kg

The bmw still has better power to weight ratio, you dont calculate it from a certain rpm. You calculate it over all. If you wanted to go down detailed route the golf is only front wheel drive with slim tyres so it would still have problems putting power down.

[ANOpax]

330southampton said:

You realise the golf weighs almost the same as the bmw right?

Golf-1451kg
Bmw-1505kg

The bmw still has better power to weight ratio, you dont calculate it from a certain rpm. You calculate it over all. If you wanted to go down detailed route the golf is only front wheel drive with slim tyres so it would still have problems putting power down.

Of course. After all, it was me who posted that the Golf is 50-100kgs lighter (depending on model, the OP wasn't specific).

And yes, I know the power to weight ratio is based on max bhp. However, the OP was wondering why his 330ci feels sluggish compared to his Golf. The answer is in the charts above.

And seeing as his golf is front wheel drive and most of the weight is over that axle compared to the 50:50 distribution on a BMW, I'm not sure the slimmer tyres will have much of a problem putting all 150bhp onto the road.

I say it again. If you don't use the rev band above 4,000rpm, the Golf is the quicker car. Based on the symptoms he's described, there is nothing wrong with the OP's car. He just needs to learn a different driving style. End of story.