4.5 Running rough?
Posted: 03 Nov 2017 15:25
For a couple of years now my 4.5 has been running rougher and rougher and suffering from some bouts of pinging.
Have done all the tried and tested stuff like removing chip, replacing PCV valve, etc etc etc. These things have been discussed in depth before.
Took it to Graham the other day and after swopping MAS sensor and distributor among other things discovered this;
Would seem that over the years the heat from aftermarket branch manifolds has slowly caused the underside of the resonator box between the air filter and intake manifold to melt allowing air in after the MAS sensor.
Borrowed one from Graham for the meantime but I can see no reason for the box so here is what I believe to be the solution;
1. Cut the box off of the intake pipe
2. Seal the hole
3. Add additional heat deflection
Will fit this weekend and see how it goes.
Moral of the story - If you fit or have aftermarket branch manifolds, ceramic coated or not modify and retain the heat deflection over the manifold.
Have done all the tried and tested stuff like removing chip, replacing PCV valve, etc etc etc. These things have been discussed in depth before.
Took it to Graham the other day and after swopping MAS sensor and distributor among other things discovered this;
Would seem that over the years the heat from aftermarket branch manifolds has slowly caused the underside of the resonator box between the air filter and intake manifold to melt allowing air in after the MAS sensor.
Borrowed one from Graham for the meantime but I can see no reason for the box so here is what I believe to be the solution;
1. Cut the box off of the intake pipe
2. Seal the hole
3. Add additional heat deflection
Will fit this weekend and see how it goes.
Moral of the story - If you fit or have aftermarket branch manifolds, ceramic coated or not modify and retain the heat deflection over the manifold.