I had a freshly rebuilt AAZ installed in my Vanagon Westfalia recently and it is louder than I'd like. I had hydraulic engine mounts installed thinking they'd help decouple a lot of the vibrations but my interior still shakes quite a bit at idle. If I speed up the revs with the pedal a bit the body vibes calm down but there is still a lot of engine noise and I'm not sure if I want to set the idle that high. I already have sound deadening all over the interior. The muffler is a Flowmaster Flow FX which I know is probably part of the problem but doesn't actually sound all that loud from the outside.
Does anyone have any recommendations for a quiet muffler that will fit a Vanagon? Are there any tuning tips for getting the top end quieter? Anything else I can do?
Thanks in advance.
Injectors might need adjusting or a new nozzle(s).
What do you have for an air filter and intake? A huge amount of noise comes from the intake. If you have a proper airbox and snorkel, it can make a huge difference. I am a fan of the Moroso spiral flow mufflers. They are free-flowing but also do a decent job at reducing exhaust noise. They aren't exactly quiet but quieter than straight-through glasspack mufflers like magnaflow or flowmaster flow fx.
Sometimes when we do engine mounts we tend to get them slightly mis-aligned. Could you have undue stress on one of them and cause the shakes?
What do you have for an air filter and intake? A huge amount of noise comes from the intake. If you have a proper airbox and snorkel, it can make a huge difference. I am a fan of the Moroso spiral flow mufflers. They are free-flowing but also do a decent job at reducing exhaust noise. They aren't exactly quiet but quieter than straight-through glasspack mufflers like magnaflow or flowmaster flow fx.
My Air box is from a dodge caravan I believe. It sits in the passenger side area but is not connected to the snorkel. Whay kind of tubing is reccomended for linking the two? I had a hard time finding something that would fit the snorkel in the past.
Update:
I adjusted my timing and reduced a bunch of knocking. I think the mechanic that put in the engine may have had it too advanced. That helped quiet down the knocking and smooth things out quite a bit. It still shakes the interior some though so I may adjust timing again and retard a bit more.
The next thing I want to tackle is the droning at hwy speeds. I'm going to try a baffled muffler and see of that makes any difference. I'm a bit worried about reducing power, but I'll accept it if its quiet. If that doesnt work I've been researching drone elimination techniques such as using a helmholtz resonator.
Not sure if a resonator was part of the OEM package. I do know that on VW Rabbits and Caddys it was part of the system. I tried to run on the hwy without one and ended up having the pipe cut and one inserted. That drone was ringing in my ears half the night after a 4 hr drive.
I have a T3 with a 1.6TD JX in stock configuration. I tried for a while with a K&N filter on the intake, noisy. I went back to the stock aircleaner, which is big and attached to the snorkle in the driver's side rear quarter vent.
I have the liquid motor mounts, they help with vibration, but not sound so much.
The injector pipes should have the clamps attached, without the clamps they 'ring' and will eventually break so I'm told.
However, the very biggest noise reducer was to use the factory engine cover, it is a sheet metal cover that encases the engine compartment from underneath. It has noise absorbent pads to cut some of the clatter. It is a pain toe remove and replace, but it keeps things quieter and the engine quite clean.
This is a link to one made from SS to give you an idea of what it looks like. The NA 1.6SD pan will fit with some mods, if you can find one.
https://www.mybusparts.de/motorschutzwanne-turbodiesel-passend-fuer-vw-t3.html