Dodgy DIYers!

[Ado1379]

Hi guys, just bought another Z3. its a 2001 2.2 Manual in Topaz blue (I think that's the right one). Got it for £1700 as i wanted a project car and its done 120k miles. First off, credit where credit is due, the car got me from Southampton to Just north of Belfast without any issues. It really does seem a solid car. however, I have noticed it sluggish at the lower end and every now and again it idles rough so I thought I'd replace the Vanos seals. The rocker cover is also leaking worse than I first thought, and now i know why!

The rocker cover stud just above the Vanos assembly has been stripped and was just left in there! and half of the nuts holding the rocker cover on weren't even done up! Ive never owned the 6 cylinder so do these have a habit of working loose?

Anyway, I have said a lot of bad words in my garage. I reckon a helicoil could fix this quite nicely as there isn't a lot of load going through these studs, just a clamping force on the gasket. so does anyone know the thread to see if I can get one that matches? i cant find my thread gauge.

 

[Pingu]

I have just done three on my kit car. They were M6. Use something to keep the swarf out of the engine, and I used a thin screwdriver with a dod of grease on it to clear swarf from the hole.

 

[colb]

Dare say the sluggish performance is due to the failing cam cover gasket and the fact it wasn't torqued down plus the stripped thread.
Air leaks into the vaccum system will play havoc with the fuel trims and cause rtough running. The extra air that has not pased through the Maf and be measured confuses the engine management when the exhaust sensors pick up extra air in excess of what the Maf saw going in. It increases the fuel at the injectors to compensate what it thinks it sees as a lean mixture. It will do this till it is adding 20% more fuel finally giving up and setting the dash EML to draw attention to the fault. More often than not holed or split rubber intake and vaccum hoses are the cause but in your case the cam cover is prime suspect. Live data showing fuel trims is a ghood indication to these type of faults and the increased visits to the fuel station because of low mpg.
Use Elring gasket brand and replace the 15 round rubber seals that sit under the cover retaining bolts originals go hard and don't torque down to provide a good seal. Use gasket sealant around the half moon shapes at the front and back of the cover, also between the Vanos where the flat edge is. I use Blue Hylomar sealant when doing this job and havn't had one fail yet.

 

[Ado1379]

We use Hylomar at work on the Aircraft gearboxes, it’s great stuff, and free for my and my light fingers
I did also think the loose fitting rocker cover would be letting air in, but as it’s all off I thought it would be stupid not to replace the Vanos seals on a car with this mileage.

 

[Pingu]

We use Hylomar at work on the Aircraft gearboxes, it’s great stuff, and free for my and my light fingers
I did also think the loose fitting rocker cover would be letting air in, but as it’s all off I thought it would be stupid not to replace the Vanos seals on a car with this mileage.

Replace the NITRILE vanos seals with VITON ones of the same dimensions. Nitrile is at the absolute limits of tolerance for temperature in an engine. VITON costs about four times the price, which makes them about £1 each instead of 25p