Serpentine Tensioner Mount Broke

Vegged-Out · Jul 22, 2019

Well, my beloved TDI seems to be doomed lately. Daughter came from college with an issue, "I see lots of metal shavings in the engine compartment."

Looked at the car, the mount for the tensioner broke (against the block not the bolt passthrough on the actual piston) and was scraping against the top pulley.

What can I do? I suspect I can get it welded, but that will be a PITA.

Thoughts?

Thanks.
Christian

IndigoBlueWagon · Jul 22, 2019

That's the bracket for the A/C compressor and alternator. Also holds the serpentine belt tensioner and roller. I don't think you're going to get that welded. And it's not cheap, about $460 from VW. I'd look for one in a wrecking yard. If you want it the part number is 038 903 139 K

Tdijarhead · Jul 22, 2019

I agree with IBW, hit the junkyard up. I think I actually have one of those brackets from when I swapped the engine into my daughters Jetta.

super1 · Jul 22, 2019

Here ya go

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/323858274864

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Mongler98 · Jul 22, 2019

I have tried MANY times to TIG, Mig, and even braze and muggy weld VW aluminium castings as well as many other transfer cases and transmissions. its not your typical off the wall aluminum, its cast and its got a high silica content that not only makes it brittle but nearly impossible to weld and not have it break off. I have welded it in the past and the ONLY way is to bury the entire thing in sand like a cast iron and heat up the entire body first and it still has issues cracking. not to mention getting the pulley in the right exact location and at the correct angle. you would need a spar part to make a jig.

TLDR: just go get a used part.

WildChild80 · Jul 22, 2019

Mongler98 said:
I have tried MANY times to TIG, Mig, and even braze and muggy weld VW aluminium castings as well as many other transfer cases and transmissions. its not your typical off the wall aluminum, its cast and its got a high silica content that not only makes it brittle but nearly impossible to weld and not have it break off. I have welded it in the past and the ONLY way is to bury the entire thing in sand like a cast iron and heat up the entire body first and it still has issues cracking. not to mention getting the pulley in the right exact location and at the correct angle. you would need a spar part to make a jig.

TLDR: just go get a used part.

I'm glad I read this, I was contemplating taking 2 intakes and making a high flow...not anymore

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WildChild80 · Jul 22, 2019

Vegged-Out said:
Well, my beloved TDI seems to be doomed lately. Daughter came from college with an issue, "I see lots of metal shavings in the engine compartment."

Looked at the car, the mount for the tensioner broke (against the block not the bolt passthrough on the actual piston) and was scraping against the top pulley.

What can I do? I suspect I can get it welded, but that will be a PITA.

Thoughts?

Thanks.

Christian

How long do you have to fix it? Pretty sure I have one and I'll be coming through on 95 or 20 in a few weeks

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Mongler98 · Jul 22, 2019

WildChild80 said:
I'm glad I read this, I was contemplating taking 2 intakes and making a high flow...not anymore

Sent from my Pixel XL using Tapatalk

not all parts are made equal. for some reason brackets and transmissions and the parts i try to save dont work well. the welds crack or have issue and with pully brackets trying to get them perfectly lined up is nearly impossible with out the original layout for a jig. Welding up a hole in a trans case is not a big deal, but a bracket, YEA its going to fail due to the tension on the pulley.
Intakes can get welded all the time and for some reason the castings for most of the engine parts like intakes, pistons, heads, and what not are all just regular cast aluminum and that CAN be welded with ease.

MOST aluminum parts are weldable but for some reason the ones i have delt with in brackets dont like it. I think VW and other manufacturers use a high silica content to make them more durable maybe? duno but the best advice i can give to welding these hit or miss parts is to do some testing.

It also comes down to the casting and how much crud is sucked into the pours of the metal.

WildChild80 · Jul 22, 2019

Mongler98 said:
not all parts are made equal. for some reason brackets and transmissions and the parts i try to save dont work well. the welds crack or have issue and with pully brackets trying to get them perfectly lined up is nearly impossible with out the original layout for a jig. Welding up a hole in a trans case is not a big deal, but a bracket, YEA its going to fail due to the tension on the pulley.
Intakes can get welded all the time and for some reason the castings for most of the engine parts like intakes, pistons, heads, and what not are all just regular cast aluminum and that CAN be welded with ease.

MOST aluminum parts are weldable but for some reason the ones i have delt with in brackets dont like it. I think VW and other manufacturers use a high silica content to make them more durable maybe? duno but the best advice i can give to welding these hit or miss parts is to do some testing.

It also comes down to the casting and how much crud is sucked into the pours of the metal.

I'm thinking I may just go with a pd150 intake and stop pipe dreaming, depends on if I can find someone with a tig box and some patience to teach me, I can torch, mig and stick...just never tried TIG

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Vegged-Out · Jul 22, 2019

WildChild80 said:
How long do you have to fix it? Pretty sure I have one and I'll be coming through on 95 or 20 in a few weeks

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I should fix it sooner than later. I have no idea when it broke.

Vegged-Out · Jul 22, 2019

IndigoBlueWagon said:
That's the bracket for the A/C compressor and alternator. Also holds the serpentine belt tensioner and roller. I don't think you're going to get that welded. And it's not cheap, about $460 from VW. I'd look for one in a wrecking yard. If you want it the part number is 038 903 139 K

Thanks IndigoBlueWagon. when I was looking at it, it looked like the injection jump gear shaft went through it. No?

Vegged-Out · Jul 22, 2019

BTW, want to thank all the quick responses here, still the best TDI resource on the internet!

WildChild80 · Jul 22, 2019

Vegged-Out said:
BTW, want to thank all the quick responses here, still the best TDI resource on the internet!

Facts...

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WildChild80 · Jul 22, 2019

Vegged-Out said:
I should fix it sooner than later. I have no idea when it broke.

Let me know, I may have to pull it off the old engine

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Nero Morg · Jul 22, 2019

If WildChilds bracket falls through, I believe Cascade German sells the bracket new for $130ish. Or if you want, the wrecker dropped a tdi last week, I could get you the bracket for at cost plus shipping. WildChild gets first dibs though

oilhammer · Jul 23, 2019

Just FYI, you'll be disassembling the timing belt too, as the injection pump is also attached to that bracket.

Chances are, the alternator pulley locked up, went unchecked, and allowed the tensioner to jackhammer on the mounting points until it broke. Usually just the threaded holes strip out. I have our machine shop put new TimeSerts in those, and they work great.

Vegged-Out · Jul 23, 2019

oilhammer said:
Just FYI, you'll be disassembling the timing belt too, as the injection pump is also attached to that bracket.
Chances are, the alternator pulley locked up, went unchecked, and allowed the tensioner to jackhammer on the mounting points until it broke. Usually just the threaded holes strip out. I have our machine shop put new TimeSerts in those, and they work great.

Thanks Oilhammer... Yeah, that's what I was thinking (disassemble timing). I need to look at the alternator pulley as well.

WildChild80 · Jul 23, 2019

Whoever can help out first go ahead and pull the trigger...but the new inserts seem to be the easiest by far

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Vegged-Out · Jul 23, 2019

WildChild80 said:
Whoever can help out first go ahead and pull the trigger...but the new inserts seem to be the easiest by far

Sent from my Pixel XL using Tapatalk

The bolt ear is broken, so need the whole bracket.

I'll IM both you about your bracket.

mjydrafter · Jul 23, 2019

I have that bracket laying here on the shelf, if you would like it let me know. If I can find a box I could put it in the mail today.

I have no idea what it's worth, make a reasonable offer shipped and it's yours

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