Siemens Fuel Injectors - Good deal or waste of money? 318i

[318i Trouble]

Hi all,

I've been experiencing lumpy cold starts on my 2009 BMW E90 N43. The RPM can fall down to 2/300 before going upto 700 and remaining there once the car is warming up. I've recently had 4 new spark plugs and a new coil installed as the car had a misfire in cylinder 3.

So far the misfiring seems to have stopped, no warning lights on the dash but just loses RPM when turning over. The car sometimes also starts up absolutely fine with no problems at all. Drives fine once started.

I'm looking at replacing 2 fuel injectors. I was quoted a price by the garage, but I've found cheaper, Siemens VDO Injectors which are priced more attractively online.

Does anyone have any experience with these or can share some insight into what they know? I'd hate to go through all the "buy cheap by twice" but at the same time is it really worth paying the extra for BMW genuine products when Siemens could offer the same?

Thanks.

[thatdude]

What's the reason behind replacing the fuel injectors?

Have you checked out other parts - fuel pump(s), throttle body issues etc etc?

[ashenfie]

You can get the injectors pattern tested which is recommend as they are expensive. I would get oem originals only and they need code for your car, so not an easy DIY job.

[318i Trouble]

Having done a fair amount of research it seems worn injectors is a common problem with the N43 engines. I've read on forums of people describing similar problems to mine and people suggesting the injectors - for that person to then follow up with a message saying new injectors have fixed the issue.

Appreciate each issue will be unique to each car, but I haven't seen/heard anything about fuel pumps or throttle body issues. Worn injectors defiantly seem to be a reoccurring suggestion.

Also when I had the spark plugs and coil replaced the mechanic said injector 2 & 3 look slightly 'wet'. I've researched this can also be a cause for hard starting when the car is warm. Which my car has struggled with.

The car has 87.5k miles and I think it's time to get them changed both as preventive maintenance and to make the starting of the car more reliable.

I'm just not sure whether to buy Siemens or BMW gen. The price difference is massive when you include VAT.

Thanks.

[Touring442]

You'd struggle to be worse than the 2009 OE ones. I bet they're still £350 each though.

[318i Trouble]

The specialist I use are charging £248+VAT per injector.

I'm looking at 2x Siemens VDO Injector for £375 from Carparts4Less.

[RanchoGrande]

Do you know what index the current injectors are? Index 11 are the latest and considered the most reliable. I believe Siemens are the only manufacturer of these injectors (other than the super cheap copies from China which you can buy on ebay)

I picked up brand new index 11 injectors from a BMW dealer up north (via ebay) for £185 each which was a good deal considering they were from a dealer.

[bmwmike]

RanchoGrande said:

Do you know what index the current injectors are? Index 11 are the latest and considered the most reliable. I believe Siemens are the only manufacturer of these injectors (other than the super cheap copies from China which you can buy on ebay)

I picked up brand new index 11 injectors from a BMW dealer up north (via ebay) for £185 each which was a good deal considering they were from a dealer.

Thats right - siemens are the only manufacturer. Also beware any on ebay which claim to be refurbished because they cannot be refurbed or cleaned. The best bet are new index 11 or used index 11 as a punt if you can get them cheap enough.

[318i Trouble]

I'm not sure what index my current injectors are - but I've gone through the service history and there is no sign of them being changed. So my guess is the car still have its original ones from 2009.

I went ahead and ordered 2x Siemens VDO Injectors. Driving about today, it started fine on both cold starts at 08:00am and 18:30. But when I stopped at the shops on the way back this evening, it struggled turning over on a warm start - hunting for RPM for 2/3 seconds before getting upto and staying at 700.

So If Siemens are the only manufacturer of the Index 11 Injectors, does that mean the ones I will be receiving will be of BMW standard Index 11?

I called the garage who will be installing them to see if they knew anything/had any experience with Siemens and they also said they believe Siemens are the ones who manufacture the those injectors. So they must be OK.

They're being installed on Friday so I'm looking forward to seeing if they fix the issue.

Thanks.

[helix402]

You need a new decoupling element for each new injector. BMW only.

[RanchoGrande]

helix402 said:

You need a new decoupling element for each new injector. BMW only.

Yup, I also did the plugs at the same time. I paid about £8 per decoupler from ebay (genuine parts)

[RanchoGrande]

318i Trouble said:

I'm not sure what index my current injectors are - but I've gone through the service history and there is no sign of them being changed. So my guess is the car still have its original ones from 2009.

I went ahead and ordered 2x Siemens VDO Injectors. Driving about today, it started fine on both cold starts at 08:00am and 18:30. But when I stopped at the shops on the way back this evening, it struggled turning over on a warm start - hunting for RPM for 2/3 seconds before getting upto and staying at 700.

So If Siemens are the only manufacturer of the Index 11 Injectors, does that mean the ones I will be receiving will be of BMW standard Index 11?

I called the garage who will be installing them to see if they knew anything/had any experience with Siemens and they also said they believe Siemens are the ones who manufacture the those injectors. So they must be OK.

They're being installed on Friday so I'm looking forward to seeing if they fix the issue.

Thanks.

When I got mine I also looked at ECP and carparts4less but it wasn't clear what injectors they would send as the listing on the site was a bit vague. I then found them cheaper elsewhere anyway and I wanted to be 100% that they would be index 11.

You should try and find out what index are in there now as Index 11 injectors don't work well with none index 11 injectors so you could end up having to replace all 4.

[318i Trouble]

I doubt my car will already have index 11 as its 09 reg.

As long as each bank has the same index isn't that alright?

[ashenfie]

318i Trouble said:

I'm not sure what index my current injectors are - but I've gone through the service history and there is no sign of them being changed. So my guess is the car still have its original ones from 2009.

I went ahead and ordered 2x Siemens VDO Injectors. Driving about today, it started fine on both cold starts at 08:00am and 18:30. But when I stopped at the shops on the way back this evening, it struggled turning over on a warm start - hunting for RPM for 2/3 seconds before getting upto and staying at 700.

So If Siemens are the only manufacturer of the Index 11 Injectors, does that mean the ones I will be receiving will be of BMW standard Index 11?

I called the garage who will be installing them to see if they knew anything/had any experience with Siemens and they also said they believe Siemens are the ones who manufacture the those injectors. So they must be OK.

They're being installed on Friday so I'm looking forward to seeing if they fix the issue.

Thanks.

For the purposes of understanding the issues you now have. I assume you have the new. injectors installed and coded. You say the car struggled to turn over, what like the starter motor was struggling?

[318i Trouble]

It doesn't happen all the time but definitely more so when warm than cold now. I press the start button and the RMP goes from 0 - 1000 and then back down to 2/300, feels lumpy for a few seconds with the needle bouncing up and down, and then it sorts itself out and stays at 700.

The new injectors haven't arrived yet. They're being installed on Friday.

[318i Trouble]

An update on the Injectors I ordered - I've received BMW Index 11 injectors made in Italy.

[ashenfie]

That's good then, finger crossed they will do the job.

[bmwmike]

318i Trouble said:

An update on the Injectors I ordered - I've received BMW Index 11 injectors made in Italy.

Italian made is probably why they give so much trouble hehe.

Where did you buy them from, and what price, out of interest? As we get into colder mornings i expect we'll see more injector related posts popping up!

[318i Trouble]

Bought from Carparts4less.

[ingenieur]

did it fix the problem? Ironic that it says at the beginning of the post about people returning to the thread to confirm whether or not new injectors improved things and leaving this one hanging....