[hakcii]

Hello all,

I drive a 08 335xi and I am trying to get feel for the price on getting downpipes installed for my car. I was quoted around 500$ to get them installed as the AWD makes it more difficult to install and I understand. However last night, my dash lit up and some codes I read state I have misfires on cylinder 2,3 and 5 and I am experiencing loss in boost pressure. I'm sure some of yall experienced this, what ended up being the cause of the problem and how much did it cost? I just want to prepare my bank acc for what's about to happen.

I can pull up the codes after work if that is pertinent info. Thanks for any help/info you can send my way!

[Pladi]

Originally Posted by hakcii

Hello all,

I drive a 08 335xi and I am trying to get feel for the price on getting downpipes installed for my car. I was quoted around 500$ to get them installed as the AWD makes it more difficult to install and I understand. However last night, my dash lit up and some codes I read state I have misfires on cylinder 2,3 and 5 and I am experiencing loss in boost pressure. I'm sure some of yall experienced this, what ended up being the cause of the problem and how much did it cost? I just want to prepare my bank acc for what's about to happen.

I can pull up the codes after work if that is pertinent info. Thanks for any help/info you can send my way!

Just install the downpipes and all your problems will go away. The cause of all BMW problems is lack of down pipes.

[relative4]

Pointless sarcasm aside, first step is pull the codes. Please use a BMW-capable scanner, don't waste time with a generic code reader.

[hakcii]

Here's a photo of my ap. Running stage 1 drive LT. Downpipes are not installed. The only mod currently installed is a drop in filter from afe and a Dinan exhaust.

edit: Of course I'm gonna tune it once the dps are installed, I have a fmic and charge pipe coming soon. Can't wait

[gurusan]

If you're worried about cost, you should sell the accessport and get mhd, then use the difference toward your other costs.

[NathanK24]

Originally Posted by hakcii

Here's a photo of my ap. Running stage 1 drive LT. Downpipes are not installed. The only mod currently installed is a drop in filter from afe and a Dinan exhaust.

edit: Of course I'm gonna tune it once the dps are installed, I have a fmic and charge pipe coming soon. Can't wait

30FF code (boost leak) could come from multiple things. One of the most common is vacuum lines leaking. Before tuning, I bought some silicon tubing (forget the diameter and how much I bought) for around $20. It took me a few hours to go through and replace all the vacuum lines but it was not expensive whatsoever, just frustrating. Many DIYs posted on this.

Other causes of 30FF could be leaking charge pipe, loose intercooler connections, and *maybe* a cracked valve cover? Not 100% on last one.

[hakcii]

Thanks for the info, I'm taking it to the shop tomorrow and see what they say. If it isn't too difficult, I may try and tackle the vacuum line replacement. My car spent most of its life in Alaska so I'm sure its due.
The MHD tune numbers are pretty impressive.

[relative4]

This is almost certainly a boost/vacuum leak, very easy to DIY if you have a compressor to smoke test or boost leak test, or you can just spray test around the charge pipe, etc.
Probably not the boost control vacuum hoses, they won't cause your misfires.
If you can't do your own troubleshooting, take it to a good indie shop - do NOT take it to a dealer.

[NathanK24]

Originally Posted by relative4

This is almost certainly a boost/vacuum leak, very easy to DIY if you have a compressor to smoke test or boost leak test, or you can just spray test around the charge pipe, etc.
Probably not the boost control vacuum hoses, they won't cause your misfires.
If you can't do your own troubleshooting, take it to a good indie shop - do NOT take it to a dealer.

Agreed on that. Dealer will not help much, just quote you very high.

One other possible cause could be the VANOS solenoids. There are two solenoids right on the front of the engine block. Very accessible, also DIYs on this. These solenoids control timing by allowing more/less oil into the head I think. Sometimes these can cause misfires and boost leak codes if they are dirty/failing. I was able to clean mine with brake cleaner, but ultimately my 30FE code (overboosting) was caused by 113k mile old boost solenoids (also called pressure converters). These are located on the side of the engine above the turbos, and have vacuum lines attached to them.

[hakcii]

Thank you all for your replies. I picked up a set of spark plugs and ignition coils to try and remedy this problem but just in case it is something like the VANOS solenoids (which I have zero knowledge on), it's at an indy shop. Once I hear back, I'll report back.

[hakcii]

For the P30FF code, I will be swapping out the pressure valve (rear) on the manifold. The shop came back saying the rear pressure converter isn't holding a vacuum.

[NathanK24]

Originally Posted by hakcii

For the P30FF code, I will be swapping out the pressure valve (rear) on the manifold. The shop came back saying the rear pressure converter isn't holding a vacuum.

Makes sense. It's pretty easy to do yourself if needed. I did both of mine as mentioned for 30FE a few months ago.