Engine Knocking - 2003 e85 2.5i

[Jacob_R]

Hello everyone!

I have recently been given a Z4 from a family friend who has not been able to make use of it due to illness.

The car has been parked up for just shy of 2 years (please excuse the condition, I’ll post an “after picture” once I’ve given it some TLC) and from my understanding has very rarely been started in that time period.

On start up, it sounds pretty horrific to my ears... I have no idea what is making this noise. However once it’s been warmed up, the noise seems to disappear and she sounds lovely!

From what he has told me, the car had its radiator and springs done before he was unable to drive it, and has seen no action since. He’s insistent that to his knowledge the engine is sound, I don’t doubt he believes this, but I just can’t ignore this horrible knock!

Plan of action is to get her scrubbed up before taking her to a specialist. But for the time being I’d love to hear your thoughts on what this could be!?

https://youtu.be/j0UShPRaJuM

All the best,

Jacob

 

[bigwinn]

Can’t load the videos chap-

What engine size is it?

 

[Chris_D]

will prob be oil starvation at the topend from sitting so long causing sticky lifter issues.
Take it out for a spirited one hour drive with regular visits to the redline in 3rd gear and all will be fine.
I (almost) guarantee it.


edit:
oh wait, i just watched the video. jesus, that's not an engine knock like i've ever heard before!
But try the above, making sure it's roadworthy first ofc.

 

[Jacob_R]

Apologies, something went wrong with the upload!

Try this: https://youtu.be/j0UShPRaJuM

The engine is a 2.5i, 84,000 miles

 

[Jacob_R]

Haha thanks anyway Chris! Like I said, the noise does go away once it’s warm so hopefully you’re on to something!

You’re recommended remedy sounds great to me!! I’ll see if anyone else has any ideas before I try it though!!

 

[ph001]

Your video doesn’t work on mobile but it does on desktop pc. I must say, it’s a very strange noise, it’s definitely not hydraulic tappets, sounds more like a timing / major misfire at idle.

Have you tried holding the car at 2000rpm or so until fully warmed up then seeing if it idles cleanly? I assume you have fitted a new battery? If not, that’s the first thing on your list. All spark plugs good? After that I’d probably be replacing the coil packs then checking the DISA valves are intact.

 

[Jacob_R]

When I held the car at a around 2000rpm the noise does disappear and it runs very well when it’s warmed up, no strange noises whatsoever. The battery has been replaced recently too so I’m told.

I did plug in my very basic reader which has said there are misfires on cylinder 5 and 6 (P0305, P0306). Maybe that has something to do with it?

I’ve searched high and low across the internet and can’t seem to find any noise similar to it.

 

[Chris_D]

Clear fault codes.
Check plugs for fouling.
Swap coilpacks from cyls 1 and 2 for 5 and 6.
Do a diagnostic again and see if cyls 1 and 2 throw codes.
Then you’ll know its bad coilpacks or not.

Could also be a sticky idle control valve. If above doesnt work, take it out, spray clean with carb cleaner, test for free movement of the vanes by holding it upside down and quickly twisting the unit clockwise/anticlockwise.

 

[enuff_zed]

The misfire codes do seem to point to the issue, but until you swap around as Chris suggests, you won't know for sure.

It would also be worth an engine oil flush and fill up with some good quality oil.

 

[Rucky]

If its been sat for 2 years you might have a couple of sticky valves. I agree with the Oil change to get rid of any moisture in the oil that was left/accumulated after 2 years of condensatioin
If you pull the plug leads from the misfiring cylinders the engine should be lumpy but not make the noise if its a stuck open valve causing it to fire back.
IMO