The not so indestructible N52

WillNattrass · Post by **WillNattrass** » Fri May 10, 2019 1:04 pm

Recently purchased a 2008 Z4 2.5si for £5750, about a month ago, and have yet to enjoy it.

My first issue came about a day after I had purchased the car, when I could smell burning coming from the engine bay. Checked it over and after removing the engine cover i was horrified to discover oil everywhere (no visible oil anywhere else on the engine so upon inspection it appeared fine) , my heart sank and I instantly thought the worst. After spending ours cleaning it all up I came to the conclusion it was overfilled and therefor splashed out of the cap.

The real issues began when my engine light came on, after an hour journey down south. I let the car cool and sit for about a day and when i returned the light had gone off, so i continued to drive it home. On the journey home the light returned and i felt a significant loss in power, a kind of flat spotting. I took the car into the garage for diagnostics and the proposed bill was scary, Engine leaks, gearbox leaks, bushing, shocks, springs and a couple other things. I spoke to mechanically trained friends and they advised that I get most of the work done, so i did. Setting me back roughly £1000. The engine light had been triggered by and issue supposedly coming from the Vanos, so they re-seated the solenoids and the light went off. Leave it a few days and again the light came on, so i proceeded to replace the vanos solenoids myself. Ran great for all of a day and then it cut out light came on again and the EML also joined it. Got the car home and again booked it into the garage, meanwhile the light keeps going on and off and the power issues seems to fixed itself from time to time.

Bring us to the present moment in time and i have just received a call from the garage to inform me that they need to take the top of the engine apart and have a look at the compression strips and cam shafts. An issue i dont fully understand but appears to do with compression in the oil system and bypassing the vanos. They have also mentioned potential fault with the vanos adjustment unit. This is going to cost me a lot of money that i dont have. I have a video explaining the work that needs doing from the technician if anyone would like to see it. Not to mention me needing a new set of tires and front shocks.

Im starting to fall out of love with the car and this is the last thing i want as i have sacrificed so much.
Ive read so many good things about these cars and their engines, its just seems like i got the bad one out of a bunch.

Any advice, help or comforting will be greatly appreciated as for know im car less and jobless hurayy...

Thanks
Will

Zeddicus · Post by **Zeddicus** » Fri May 10, 2019 1:41 pm

You said you have purchased the car one month ago. I assume this was a private sale otherwise you would certainly have a warranty coverage for the engine related issues?

The N52 engine is a reliable engine as most of 6 cylinders inline are reliable engines, but surely not indestructible. This engine has all kind of advanced technology features that allow it to be a relatively high N/A efficient engine. You have named the VANOS, there is also the DISA and you may see these systems starting to degrade over time and use - especially if the car has a lot of miles performed on short distances.

Luckily, you should find BMW specialists that will be able to bring back the engine to its original performances at a better cost (and with better knowledge sometimes) than BMW dealers.

It is a shame though that you're experiencing such problems with your "new" car, the E85/E86 are usually very nice machines and hard to let go... I hope you will find a way to enjoy it at its best very soon.

ph001 · Post by **ph001** » Fri May 10, 2019 2:17 pm

Please do post or link to the video. None of the stuff your mechanic suggests are typical faults with the N52, the vanos in particular is extremely reliable on these engines. The oil everywhere under the cover would imply that it has got onto the eccentric shaft sensor. Once that happens it seems to kill them. Unplug it and check for oil in the connector, sometimes cleaning the connector and drying it helps but more often than not a new eccentric shaft sensor is required. With a bit of luck, that’s all the problem will be.

Marlon · Post by **Marlon** » Fri May 10, 2019 2:28 pm

This is a sad tale

As mentioned its very unusual to hear such problems with the N52 - little comfort for you though. Hope you are able to sort it

Jembo · Post by **Jembo** » Fri May 10, 2019 3:20 pm

A very unfortunate tale, as my old 3.0 was a very reliable car.

I wish the both of you a speedy recovery & an enjoyable summer. If you’re in Kent drop me a PM

buzyg · Post by **buzyg** » Fri May 10, 2019 4:45 pm

Gutted for you OP. Hope you can get it sorted.

Mr Tidy · Post by **Mr Tidy** » Fri May 10, 2019 8:10 pm

Sorry to read your tale of woe OP.

N52 engines are generally pretty reliable - I sold an E91 325i Touring with the same engine as your Z4 last month and it was on 139K miles! The only issue I had with it was the dreaded death of the electric water pump.

I'd be looking for an independent BMW Specialist to get it checked out - I've got a great one near me.

But I hope you can get it sorted then enjoy the summer.

NickDE · Post by **NickDE** » Sat May 11, 2019 12:58 pm

I just hope you don't have what I have:

viewtopic.php?f=3&t=114247

I have no solution right now, so just live with the light coming on and off and the occasional rough idle.

firebobby · Post by **firebobby** » Sat May 11, 2019 7:55 pm

Sounds like the car was sold with faults, did you not get it inspected before buying ?
Hope you get it sorted soon

WillNattrass · Post by **WillNattrass** » Fri May 17, 2019 6:50 pm

NickDE wrote: ↑Sat May 11, 2019 12:58 pm I just hope you don't have what I have:

viewtopic.php?f=3&t=114247

I have no solution right now, so just live with the light coming on and off and the occasional rough idle.

Hey Nick and everyone else
I've got the car back from the garage now and after much headbanging

,sleepless nights and some pricey trips to the garage. I beleive the issue is sorted. It sounds very similar to what you are explaining in your post Nick, excpet i did experiance some power issues.
The parts that have subsequently been replaced are the vanos adjustment unit, compression rings and a few other gaskets and seals. So far the issue is yet to return and the car is running smoothly. Hopefully this will help you in discovering the root of your problem, but i would suggest somewhere in the timing system is where it will lay.

Mr Tidy · Post by **Mr Tidy** » Fri May 17, 2019 10:03 pm

Glad to hear it seems to be sported.

Now all you need to do is enjoy it!

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