Intercooler testing

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
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pwack
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Intercooler testing

Post by pwack » Tue Dec 12, 2023 11:38 am

Hello All

After following SKYEGTBs excellent guide on testing intercoolers and finding a few bits that made it pretty straight forward I thought id put a bit of info on some parts that can be easily bought to make the testing easy.

I must preface this with saying that I had the intercoolers removed with the hoses as well.

In B&Q they sell plastic cups that you put under the feet of tables etc but they are a perfect fit in the large ends of the intercooler hoses , I used these to seal the hoses to do a pressure test
int1.jpg
I then bought some threaded schrader valves from amazon

https://www.amazon.co.uk/Emma-Motocycle ... 09&sr=8-17

With these 2 parts you have this


int2.jpg
It fits perfectly in the large end of the intercoller hose

Both hoses have a big and small end , so one hose has a large diameter free and one has the small diameter free , on the small diameter hose side the blank has to be fitted inside the hose by the intercooler output flange
int3.jpg
the basic diagram below shows what I am trying to get across
int4.jpg
int4.jpg (24.88 KiB) Viewed 2714 times
You can use a stand up bike pump with a gauge as this should provide enough pressure.

int5.jpg
int5.jpg (12.55 KiB) Viewed 2714 times
Dunk the intercooleres in a bucket of water and pump away!!

What I found when I tested mine was that the car must of been running normally aspirated as both the intercoolers wouldnt hold any pressure at all , literally nothing!!

I then followed SKYEGTBs instructions and sealed the entire core ends with JB Weld , both intercoolers now hold pressure without an issue , I cant tell you what the performance difference is yet as I am just in final throws of putting the engine back in and conecting it up to here it run (Hopefully !!!!!!!!) for the first time as my 6 was a non running project.

Hope this helps someone looking to do a intercooler test :)

Mɐʇʇ
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Re: Intercooler testing

Post by Mɐʇʇ » Tue Dec 12, 2023 11:40 am

I use these : https://www.ebay.co.uk/itm/330563816336
I like your schrader valves - might have to get some.
"not a professional engineer, mechanic and mechanist"

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Shoppinit
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Re: Intercooler testing

Post by Shoppinit » Tue Dec 12, 2023 11:45 am

Nice!

There's a faster way of knowing if your intercoolers are leaking though. Here's the method:

1. Are your intercoolers OE?
2. Yes: they are leaking.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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skyegtb
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Re: Intercooler testing

Post by skyegtb » Tue Jan 16, 2024 12:14 am

LOL, good to hear that my guide is still proving useful!
2003 RS6 MTM 568

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audi_driver79
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Re: Intercooler testing

Post by audi_driver79 » Sun Sep 22, 2024 9:04 am

Hi,
Sorry to resurrect this old thread but my intercoolers have been leaking for awhile and need to get them done when I get my belt changed. They are throwing up a running rich code as well. I've bought a second hand pair to get them re-cored and the seller states they were working fine so should I just put them under pressure as above to test? As they are OEM are they living on borrowed time if they do hold pressure now? Am I better just sending them away to get professionally done by Airtec then they will have some warranty?
C5 RS6 Avant Mugello Blue, Original Springs.
1997 Audi Cabriolet 1.8 for when its Sunny!
2001 A2 1.4tdi 75bhp.

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Shoppinit
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Re: Intercooler testing

Post by Shoppinit » Sun Sep 22, 2024 9:26 am

Shoppinit wrote:
Tue Dec 12, 2023 11:45 am
There's a faster way of knowing if your intercoolers are leaking though. Here's the method:

1. Are your intercoolers OE?
2. Yes: they are leaking.
I stand by this. Send them off to get done and then you can fit and forget them.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Shoppinit
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Re: Intercooler testing

Post by Shoppinit » Sun Sep 22, 2024 9:42 am

You can see when they leak. They will have a corner that is stained with oil. Although your vendor may well have cleaned them up.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

steve2003rs6
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Re: Intercooler testing

Post by steve2003rs6 » Sun Sep 22, 2024 2:56 pm

Hope you get a similar result to mine after replacing /repairing the leaking inter coolers.
Had my coolers fully refurbished by Airtec, They did a fantastic job.
Replaced all (8) oe hoses for silicon from Roose Motorsport.

Let me just say that I have always considered my car to be very quick, as they all are.
But with the “new” inter coolers
Wow what a gain in performance.

Shoppinit had previously informed me of the power gain. When you fit new inter coolers.
But I didn’t expect such a huge difference.

I just wish I had measured the before and after figures.

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audi_driver79
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Re: Intercooler testing

Post by audi_driver79 » Mon Sep 23, 2024 11:33 am

OK I'll be getting them re-cored then I don't have to worry. After 13 years ownership I sometimes wonder if I've got used to the speed so if it does improve performance I'll be a happy chappy. I daily my A2 75bhp so the RS6 always feels faster than that no surprise there but it's still a lovely little car to drive.
C5 RS6 Avant Mugello Blue, Original Springs.
1997 Audi Cabriolet 1.8 for when its Sunny!
2001 A2 1.4tdi 75bhp.

steve2003rs6
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Re: Intercooler testing

Post by steve2003rs6 » Mon Sep 23, 2024 12:06 pm

Ditto after 12 year’s ownership I reckon I also just got used to the speed.
As Shop says if the coolers are leaking oil in the corners then they need attention.
Mine had oil staining in both bottom corners on both coolers.
Last edited by steve2003rs6 on Mon Sep 23, 2024 12:09 pm, edited 1 time in total.

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Shoppinit
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Re: Intercooler testing

Post by Shoppinit » Mon Sep 23, 2024 12:08 pm

I do like the A2.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

steve2003rs6
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Re: Intercooler testing

Post by steve2003rs6 » Mon Sep 23, 2024 12:15 pm

Ps. If you send your coolers to Airtec the new cores are slightly thicker than the original. Not a problem though as they are easy to reinstall.
Cost was approximately half the cost of Wagner’s

Pps That’s a great test rig for pressure testing the coolers.

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