X5 4.8i crank but no start

[capsx5]

I have a 2008 x5 4.8 the car shut down on the side of the road and sat for 2 years and had oil leaks. Recently changed the valve cover gasket, replaced alternator and battery, do i need to 'REGISTER NEW BATTERY' ? Also, had a lot of rain recently and water may have gotten. I have a cheap ODB2 scanner and getting U0155 - error communicating with icm. I try jump starting with 2 cars hooked up and get it to crank but never fire, no spark. I tried disconnecting the IBS on the negative terminal and replaced the fuel pump relay. I have ordered the KCAN cable but will take a few days to arrive.

[josiahg52]

The modern BMW - and a lot of other vehicles - have Intelligent Battery Sensors. The IBS monitors battery performance and is supposed to optimize battery charging as the battery ages which may lengthen battery life. I suspect that it also helps them attain fuel economy targets.

A new battery, at a minimum, needs to be registered which simply tells the sensor that a new battery has been installed.

If the battery type is changed, i.e., AGM to/from FLA, the battery must also be programmed.

If a battery with a different capacity is installed, the new battery must also be coded.

You don't have to perform these steps to get a new battery installed and your BMW up and running but it probably doesn't help the new battery last as long as it could.

[capsx5]

well i had a mobile mechanic scan codes with autel All System Scanner - the immobilizer was active and tried clearing. The same 3 error kept popping up for EWS, DME, and immobilizer. Was told the key lost programming and had to get a new key programmed from the dealer. I did see another local guy offered key programming and wondering if this is something i could have possible done myself with the proper tools. Now the car is attempting to start but still wont stay running. I think the gas has sat for a year and went bad. Going to start inspecting fuel system components today.

[ard]

Its not the battery.

The EWS abd DME lose 'sync' when without power and/or hit with lots of jumping


You dont need a new key coded. You need to resync the EWS and DME

[ard]

Oh, these cars are INCREDIBLY susceptible to people who dont know WTF they are doing.

[pshovest]

Originally Posted by capsx5

........ I think the gas has sat for a year and went bad. Going to start inspecting fuel system components today.....

If the DME/EWS/Immobilizer codes are still present, I would focus there. If it runs on starting fluid, then I'd look at fuel system.

[capsx5]

we tried to align the dme (forgot the terminology, we used the autel scanner) but the same codes kept popping up.
Eventually had a different mobile locksmith cut a new key (needed one as i was missing the metal insert anyhow) and he was able to do the coding too, with the same autel scanner.

The car eventually fired up after this, so thats great news, but now the engine is dumping oil from somewhere toward the rear bottom of the engine. Hoping its a gasket or other connection.
Will be devastating if there is a crack engine block or something else catastrophic.

[josiahg52]

Leaking oil cooler thermostat gasket OR alternator bracket? I think that's a common leak area on the 4.8L

[capsx5]

yes it was leaking from the common problem - oil cooler/alternator bracket
the car is running rough and sometimes not at all on the driver side cylinder bank. 5678.
the mechanic is suspecting a timing issue and wants $1,000 just to troubleshoot/diagnose.
Are all the timing controlled by cam sensors and valvetronics system? What else could be cauising the timing issue mechanically? Thanks in advanced, feel like its close to getting back on the road!

[ard]

So there are NO check engine lights and no codes. Using a BMW-specific scanner?

No timing codes, no vanos codes…nothing…perfectly clean, just these running issues you stated?!?

I can think of many things it might be, but we all do a disservice tossing out ideas when we are just blind. (Like the vanos solenoids sludged up, due to oil issues and sitting, now causing timing…)

Codes. Or pay “the” mechanic…or find another shop… $1000 seems way unreasonable, so I’d move on.