So I''ve got a vanagon with a 1.9 AAZ. A while a go the turbo went out and I simply removed it, plugged up the turbo oil lines and re routed exhaust and air filter(k&n in drivers side D pillar) What can be done about the noise! No tach but with stock diesel tranny in 4th It's bearable untill about 40mph and then a very unpleasant droning/bone rattling vibration increases until about 55 when it's still loud but smooths out a bit. It's definately rpm dependant and will do it in any gear at the same rpm range. I know putting the turbo back in will soak up some of the noise, but i'm satisfied with the power of the NA and like its simplicity. Things I've done to try and quite things down a bit include. extra carpets over engine compartment (below cushion) , removed wall panels and installed butyl rubber on sheetmetal and fiberglass insulation... I havn't tried but have thought about wrapping the exhaust in some kind of heat proof tape, different motor mounts, different muffler, different manifolds. Possibly some kind of clear plastic partition right in back of rear bench. I need to quite her down, its driving me mad and is the only complaint I have with her. Let me know of any ideas you all have . Thanks, Paolo
how worn are your motor mounts? im kinda almost thinking thats where most of your noise is coming from. how good is your exhaust system hung? are all the hangers rubber isolators? its not touching anywhere is it? no shiny spots on the pipe? do you have an air box and panel K&N filter, or a intake duct with a open element K&N pod filter with no box?
these diesels, as n/a, make ALOT of intake noise if they dont have a proper air box fitted. im kinda thinking you have just an open pod filter. and i bet thats where most of your noise is coming from..
why not just re-fit a turbo to it like theres supposed to be? do you have any idea how much the turbo quiets things down? its the best muffler you can have, it quiets things down substantially, and makes more power.. its a win-win situation..
it doesnt just quiet down the exhaust either, it also quiets the intake quite a bit also. well, you figured out that it makes things A BUNCH louder with it not installed..
i would say to fit some new motor mounts if they are old or worn, and either fit a good air box and muffler to it, or else put your turbo back on.. i would just put another turbo back on it, personally.. if nothing else, just for the increased torque, and mileage gains..