Turbo 98 e39 528i m52b28

[Tubs McGubs]

I made the mistake of impulse buying a 98 turbo e39 528i when I have no previous wrenching experience nor a lot of BMW knowledge. The car builds boost but breaks up at around 4k RPMs. For the past year and a half I have been doing research on turbo m52b28s and have not come across much besides the recommendation of getting a new ECU. It (supposedly) has a CES copper head gasket spacer 9:1 compression, walbro 255 fuel pump, M3 5-speed, s52 head, technica motorsports tune, CXracing top mount manifold, Garret GT35 turbo (actually seems to be an eBay turbo due to the lack of a Garret logo), Hallman ES boost controller, Tial BOV, Mishimoto intercooler, Gplus oil cooler and 60lb injectors. I have not touched the car besides putting in NGK 4644 spark plugs gapped at .021 and it didn't seem to make much of a difference. I haven't done much do to lack of tools, experience, money and the car runs so I dont want to ruin anything. I am not sure if I should part this thing or try to get it running well because turbo e39 528is are few and far between. I've heard with ARP head studs and stock internals these things could make up to 400hp. Any help or advice would be greatly appreciated. I'm sorry if anything I said is incorrect as I said I am new to this and not an expert by any means.

[edjack]

What codes are stored? What are the short-term and long-term fuel trims? What do you mean by "break ups?"

[Tubs McGubs]

What codes are stored? What are the short-term and long-term fuel trims? What do you mean by "break ups?"

I am not sure of anything that has to do with the tune for I have not gotten it tuned nor have I looked at it myself. It stops making boost and the car bogs.

[DennisCooper]

Hi,

I'm sure there's a good few members here who can give you useful tips and things to try and hopefully they'll come in with those on the thread for you soon.

My suggestion would be to find and research any good, expert, knowledgeable local specialists you can take the car to for more in depth fault finding etc. Hopefully they'll be able to relatively quickly and inexpensively diagnose things and discuss with you. From that point, you can evaluate what you'd want to do next and in which order depending on the depth of your wallet.

Cheers, Dennis!

[philly98540]

Post up your issue on the Forced Induction forum. There are lots of guys over there that have turbo experience with your set up.

[jicaino]

Contact Jack De La Vega. He's a user here but I cannot remember his handle. He built a wicked 530i turbo and he has a performance shop in Miami, FL.

[tptrsn]

Those eBay "GT35"s are pretty awesome for about $140 shipped. The CX Racing top mounts are kind of known to crack quite frequently. Should be a fun car though when sorted, how much do you want for the car complete?

[jicaino]

Those eBay "GT35"s are pretty awesome for about $140 shipped. The CX Racing top mounts are kind of known to crack quite frequently. Should be a fun car though when sorted, how much do you want for the car complete?

Since you're pretty much an expert in turboing cars (at least compared to me) I want to ask, is there any bottom mount manifold avalible for the M52? I have a really nice 523i and while I still can enjoy the car as is, I'd love to get something extra out of it.