When your youngest car is 15 years old you always have maintenance and stuff to do and when you have four cars and a project car the list is long! / #BMW
This month I have had to focus on the daily fleet. My #BMW-330i-E46
has been neglected of late and I have been meaning to do the DISA valve (the DISA valve alters the inlet runner length to aid low-down torque) for some time. My #BMW-330d-E46
has started to get smelly in the cabin and the fuel economy has got worse. The #BMW-330d
has the label of parts car and has always been a bit of a beater but this doesn’t change the fact that it still needs to be maintained to retain some of its value and keep the engine going if I do break it!
As with all cars there are well-known faults and maintenance issues that raise their head in the car’s lifetime. I have addressed a lot of them in the past with the 330i: the cooling system, Vanos seals, CCV, lower control arm bushes, rear trailing arm bushes, oil filter housing gasket, rocker cover gasket… the list of repairs is really quite long!
The DISA valve in the #BMW-M54
engine is a component that wears over time and it can then fail and the results can be catastrophic as the engine ingests the plastic… yes again plastic. BMW, why do you love plastic so much for your components?!
The M57 engine is an all-time great but there are some well-known problems, one of which is the exhaust manifold. The manifold is made from stainless steel and it is made up of several parts which are welded together. As a result the manifold, after many heat cycles, can crack along the weld lines causing it to blow. This means the engine bay has exhaust gases in it, leading to a smelly cabin. The turbo fails to spin up how it should as exhaust gases are lost before reaching the turbo and there is then a knock-on effect on fuel economy as induction is altered.
As with Vanos kits there are various companies who offer off-the-shelf solutions for these common issues with various cars (not just BMWs). X8R has been the company of choice for me this time as they offered solutions for both DISA valve and manifold issues. They also offer Vanos seal replacements and in addition to that they don’t just cover BMWs, they offer parts for pretty much most makes!
The DISA solution is to replace the plastic flap in the unit with an alloy one and a replacement stainless steel spindle. This means that there is no longer a risk of the flap and spindle failing. The replacement manifold, meanwhile, is a cast item which is substantially stronger and more robust than the stainless OEM item. All new gaskets and fittings are supplied to ensure the replacement manifold is secured and sealed properly. The DISA valve is a relatively simple job which requires removing the unit from the side of the inlet manifold but the same cannot be said for the manifold swap. You can either come at it from the bottom and up, or from the top and down and both ways are a complete faff and have their respective problems. Without a two-post lift I am going top down! More on this next month where I will cover both jobs!
DISA-valve-replacement-kit . New manifold for the 330d.