TheSamba.com :: View topic - muffler suspension (hanging) system for 1.9 Diesel

Fri Oct 15, 2021 10:17 pm

I have a 1.9 diesel engine and am pretty happy with it. The only big issue I have with this engineering is the attachment of the muffler to the oil pan.

I really would like to find a way to attach the muffler to the frame or to weld it with brackets to some other stronger points of the engine block, just not to the oil pan.

This German engineering is really unfortunate to attach the muffler to the oil pan. The oil pan is the most fragile part (made of aluminum) and most critical part and I risk to lose my engine if the muffler's weight cracks or breaks the oil pan. Since the engine is vibrating quite good and with it also the muffler, the huge weight of the muffler moves and shakes all the time and puts a lot of pressure on the 3 bolts which attach the muffler with a metal plate to the oil pan. One of those bolts already broke a hole through the oil pan (which I closed with JB weld) and I did not use it anymore. Out of the 2 remaining bolts now the second bolt is making a crack in the oil pan and some oil starts leaking slowly from there. With that I decide to not drive anymore because it can crack the oil pan, lose my oil in 1 minute and lose my engine.
So, long story short, I am looking to attach the muffler to something else but the oil pan - any tips of how this has been done successfully. I know so much that you can't weld the muffler firmly to the frame or to the engine brackets because it has to move freely with the engine.

Sat Oct 16, 2021 3:09 am

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Dave

Sat Oct 16, 2021 10:36 am

There are several different means of attachment to the block. One must get creative. If you google tdi Vanagon exhaust you might get some ideas.

Here is my last iteration.

https://www.thesamba.com/vw/forum/album_page.php?pic_id=2186753

I started with a short exhaust but found the tip “waved around” do to the vibration so I added the section at the rear of the van.

All of mine are attached to think plates bolted to the block. Between those plates are rubber bushes of varying types.

Best practices seems to indicate that you cannot mount to anything other than the motor. The motor flexes and will put even more strain and movement into the exhaust.

Sat Oct 16, 2021 10:47 am

I would think that if you have all the factory mounts with all three rubber mounts included, that the pan would not be in any danger. There are a ton of these diesels out there that have been running for decades now without issues.
Does your set up have all the rubber mounts? Usually the rubber mounts will fail before anything else does...

Sat Oct 16, 2021 11:00 am

There's no danger of the pan getting damaged if the hangers are isolated, the factory system with 3 mounts seems to be quite stout

You can buy all the brackets and mounts still, check out Brickwerks from your other thread, and it all fits like factory

There's pictures of the factory layout and the build we did for my van in my signature, using all the factory parts from Brickwerks

Sat Oct 16, 2021 11:04 am

The engineering of the stock system is bulletproof. Fastening to the frame will cause more vibration in the chassis and will also greatly increase the broken exhaust parts, failed gaskets, broken exhaust studs in the head, etc...

Get a new oil pan and the correct stock exhaust parts.

Sat Oct 16, 2021 1:15 pm

The stock exhaust setup is completely untenable for the AAZ. See my 2½” exhaust build here:
https://www.thesamba.com/vw/forum/viewtopic.php?t=728825
You really need 2½" exhaust for proper flow through the turbo, low EGTs and low crankcase pressure. Don’t postpone it for years like I did trying to make that stock setup work.

In the end I went with the chassis mounted exhaust because all that stuff hanging off the engine is no end of trouble. The long flex section, in contrast to the shortie pieces you typically see, will help to dampen the drone noise coming from the chassis.

Wed Oct 20, 2021 10:27 pm

Thanks for your comments guys. I saw some of your set ups and pictures however I am not sure how they allow the exhaust and muffler to move freely. Most seem to be firmly mounted to the chassis. Is the flexible part of the exhaust piping the only part that allow for flexibility and movement?

What do you mean by "hangers are isolated""

And where can I get the factory rubber mounts? I dont think mine uses these

Rmcd what rubber bushes are you using and where did you get these?

Does anyone have an experience with the FAS (Foreign Auto Supply) muffler hanger kit? At $189 is a bit pricey but it seems it is engineered to allow the muffler to move freely eventhough it is attached to the chassis

Wed Oct 20, 2021 11:37 pm

johnnytod wrote: …

What do you mean by "hangers are isolated""

And where can I get the factory rubber mounts? I dont think mine uses these

Rmcd what rubber bushes are you using and where did you get these?

…

My rubber mount had failed on the drivers side which caused whole exhaust to vibrate enough that the passenger side plate that attached to the oil pan broke. I ordered new rubber mounts from Bus-Ok in the Netherlands - one for each side.

https://bus-ok.nl/T25-Exhaust-Mount-Rubber-For-CS-JX-Engine-Codes-068251393A.

Ordered a new mounting plate also -
https://bus-ok.nl/T25-web-plate-right-side-exhaust-system-all-Diesel-engines-OEM-partnr-068251370

Here’s one in the classifieds, pricier, but a bit closer to home -
https://www.thesamba.com/vw/classifieds/detail.php?id=2305448

Made a huge difference.

Thu Oct 21, 2021 5:14 am

I can see a lot of people here like the stock muffler mounts. They never worked for me. I replaced all the rubber mounts several times before I gave up no them. First made mounts from angle iron that bolted to the factory spots on the oil pan and had hangers that dropped down from the top with American stile hangers. I run it that way for about 100,000 until my wife cleaned it off backing over a curb. Now I have the system that FAS sells that hangers the muffler off the body it has been on the van for about 30,000 miles it works as well but you need a good flex joint where the pipes run to the back of the van. John

Thu Oct 21, 2021 8:35 am

Rockauto.com has the diesel rubber/metal bonded exhaust mounts for $7 CAD. Brand name of the part has changed. Hopefully, QC of part has not:

https://www.rockauto.com/en/moreinfo.php?pk=1080174&cc=1286298&pt=5804&jsn=841

If installing exhaust as per stock design, consider adding a 4th mount at passenger side of exhaust. Some comments here on that:

https://www.thesamba.com/vw/forum/viewtopic.php?t=709076&highlight=exhaust+mount

I think muffler length and weight can be factors here.

Using construction adhesive 'liquid nail' type stuff or ? to repair otherwise good mounts that have failed prematurely might allow part to be useable for some miles.

Neil.

edit: This is the stock "mount" I refer to.

Thu Oct 21, 2021 8:48 am

johnnytod wrote: Thanks for your comments guys. I saw some of your set ups and pictures however I am not sure how they allow the exhaust and muffler to move freely. Most seem to be firmly mounted to the chassis. Is the flexible part of the exhaust piping the only part that allow for flexibility and movement?

the idea is the suspend the muffler and the whole system off the engine, then it doesnt need to flex much if at all since the whole thing is vibrating together. the rubber isolators should keep it from breaking anything as it heat cycles.

first pass at the exhaust build on my tdi swap, we looked at some etka drawings and saw there was a variant with only 2 mounts so we came up with this to start with:

based on the second system shown here:
https://volkswagen.7zap.com/en/usa/vanagon/va/1983-4/2/251-35010/

then there was discussion in my swap thread about how that was a less than ideal layout
https://www.thesamba.com/vw/forum/viewtopic.php?p=9329256#9329256

Quote:
Stock exhaust uses three of the rubber isolators. The third is mounted on top of the driver's side aluminum mounting bracket. That top one prevents twisting force on the other two. Without it, they will fail very quickly, probably in less than 1000 miles. If both fail, your exhaust will be hanging by the flex connections and by the flange at the turbo. Yipes. IMO, the isolator on top of the driver's side bracket is the minimum requirement. Placing a similar one on the passenger side would be a good idea also. It would also be a good idea to have a fail safe mode so that if any/all of the isolators fail it might get noisy but nothing will get bent/broken.

based on that sound advice, we added a 3rd strap to the system on the drivers side top (you can see it here over the top of the exhaust side mount) to mimic the first layout in that parts diagram

you can see it curving over the top of the motor mount in that picture
all three mounts use those factory rubber isolators, and anecdotally - just wiggling the thing by hand from the very end - it got SIGNIFICANTLY firmer with the addition of that 3rd strap

edit - as usual waldos on point

?Waldo? wrote: The engineering of the stock system is bulletproof. Fastening to the frame will cause more vibration in the chassis and will also greatly increase the broken exhaust parts, failed gaskets, broken exhaust studs in the head, etc...

Get a new oil pan and the correct stock exhaust parts.

/thread :lol:

Thu Oct 21, 2021 7:19 pm

Would it make any difference to the exhaust system wear and tear if the OP's engine has a turbo or not?

Fri Oct 22, 2021 2:14 pm

valvecovergasket wrote: johnnytod wrote: Thanks for your comments guys. I saw some of your set ups and pictures however I am not sure how they allow the exhaust and muffler to move freely. Most seem to be firmly mounted to the chassis. Is the flexible part of the exhaust piping the only part that allow for flexibility and movement?

the idea is the suspend the muffler and the whole system off the engine, then it doesnt need to flex much if at all since the whole thing is vibrating together. the rubber isolators should keep it from breaking anything as it heat cycles.

first pass at the exhaust build on my tdi swap, we looked at some etka drawings and saw there was a variant with only 2 mounts so we came up with this to start with:

based on the second system shown here:
https://volkswagen.7zap.com/en/usa/vanagon/va/1983-4/2/251-35010/

then there was discussion in my swap thread about how that was a less than ideal layout
https://www.thesamba.com/vw/forum/viewtopic.php?p=9329256#9329256

Quote:
Stock exhaust uses three of the rubber isolators. The third is mounted on top of the driver's side aluminum mounting bracket. That top one prevents twisting force on the other two. Without it, they will fail very quickly, probably in less than 1000 miles. If both fail, your exhaust will be hanging by the flex connections and by the flange at the turbo. Yipes. IMO, the isolator on top of the driver's side bracket is the minimum requirement. Placing a similar one on the passenger side would be a good idea also. It would also be a good idea to have a fail safe mode so that if any/all of the isolators fail it might get noisy but nothing will get bent/broken.

based on that sound advice, we added a 3rd strap to the system on the drivers side top (you can see it here over the top of the exhaust side mount) to mimic the first layout in that parts diagram

you can see it curving over the top of the motor mount in that picture
all three mounts use those factory rubber isolators, and anecdotally - just wiggling the thing by hand from the very end - it got SIGNIFICANTLY firmer with the addition of that 3rd strap

edit - as usual waldos on point

?Waldo? wrote: The engineering of the stock system is bulletproof. Fastening to the frame will cause more vibration in the chassis and will also greatly increase the broken exhaust parts, failed gaskets, broken exhaust studs in the head, etc...

Get a new oil pan and the correct stock exhaust parts.

/thread :lol:

1989 and on had the second style muffler mounting. Still 3 rubber isolators but rathers than having the brackets on the end of the can, they had them more inwards with angle brackets bolted to the can. There's also a wider version of the rubber isolator, a fatter square chunk of rubber while keeping the hardware in the same location.