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How to do a 710N recirc valve upgrade!

Posted: Sun Aug 08, 2010 9:45 pm
by bkf_uk
Right first things first, this is the best upgrade you can do to the turbo engine if you have increased the boost pressure either with an "MBC" or Richmod.

You will tend to find that after increasing the boost the standard "dump Valve" and the recirc valve on the end of the ICV (see pic below) just wont last, you will suffer from surging from the turbo (not good) and the idle will be all over the place. (you might even find like i did that the crank case is getting pressurised and the dipstick for the oil is pushed out and oil sprayed over the bonnet).

Position of the "Recirc Valve" on the ICV
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Shopping list:-

1, Go to B+Q (or any local hardware shop) and get a meter of 22mm clear pvc pipe (should cost no more than £3) should be the same as the stuff in the pic below.
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2, Go to your local VW/AUDI dealership (dont get a secondhand one it's not worth it!) and order 2X 710N valves VW/AUDI part number 06A145710N Should look the same as below.
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3, Get 6X 20-25mm Hose clips

Ok Here is the "HOW TO" part.

Remove the "Dump Valve" from the intake near the turbo noting how it was positioned (there is a locating tab to indicate fitting) then throw it in the bin. Now fit 1 of the 710N valves in it's place using 2 of the new hose clips you bought (dont reuse the old ones there crap). Thats the easy part done.

Remove the ICV from the engine and put to one side, now remove the recirc valve that was attached to it. you will have to cut the solid plastic pipe on the bottom of the valve with a hacksaw (it wont pull off!!) also cut the vacum hose off aswell (the recirc valve will break before it gives you the hose!!)

Using the ICV and the other 710N dump valve messure how long a piece of hose you will need to connect them together (allow 20mm extra for a gap!) and cut this length twice from the meter of pvc pipe that you bought.

Now go boil the kettle (no your not getting a cuppa!) place one of the pieces of pvc pipe into a mug and pour boiling water onto it (it becomes soft and pliable when it's hot, just watch your fingers though!), leave for a minute and then take it out. as soon as you have taken it out try fitting it to the end of the 710N valve (it will take a few goes but will eventualy stretch to fit). Once one is on repeat again for the other end.

Now the 710N valve should have the 2 bits of tube streched over the ends of it, allow the tube to cool and then attach the end that has the locating tab to the end of the icv then tighten it down using 2 of the hose clips you bought.

Now reinstall the ICV to the engine. When the ICV is in place push the solid bottom hose you cut with a hacksaw into the other piece of clear tube and again tighten it using the last 2 hose clips you bought. Finaly attach the vacum hose and your done!

When finished It should look something like this! :-
Image

Hope this helps people, as i know for a fact the valve on the ICV is a real brittle bugger!

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 8:14 am
by bbf
this is a very very strange place for a recir valve!

it should be as a bypass on a primary of the turbo, not before the idle regulator!

it's a direct swap when in correct place..

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 8:36 pm
by bkf_uk
BBF if you read the how to again you will see that i have specified using 2 recirc valves. One to be used as standard, but also using one to replace the diaphram valve that sits on the ICV that tends to break if you look at it, or the insides fail when your increase the boost. which causes an air leak at idle and a boost leak into the crankcase when under pressure. However by using the recirc valve it acts the same way as the diaphram valve and is able to take the added boost without failing.

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 8:59 pm
by bbf
ok. i see now. i have no valve on my turbo there, just the evap valve system.

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 10:14 pm
by spree
This is great. I'm deffo going to do this as the L shaped connector on that rubbish little valve snapped on me when I cleaned my ICV and I had to attach the vacuum pipe to the stump that was left....then the rubber mount that the ICV sits in broke as it was then under slightly more stress due to the extra pull of the now tighter vacuum hose... :roll:

I see that the ICV no will no longer even need to sit in that thing if I do this. Yay! And the car will idle better and boost better. Double yay!

The only thing that I am concerned about is my insurance as I didn't want to mod this car but its not really a modification as such really is it...?! How does insurance stuff like that work in this case?

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 10:51 pm
by bkf_uk
Spree i wouldn't even class this as a "modification" in that class, as you are only substituting a poorly made part for a better quality part. i would say it's no different from fitting a genuine volvo air filter or a FRAM air filter from a motor factor. It's just an aftermarket part that doesnt increase the power of the engine (the richmod or mbc does that)

Idealy the icv should be in that rubber mount, but mine was missing when i bought the car hence my pic fails to show it! also i would recomend fitting new vacum lines, easily avalible from most motorfactors by the meter. (or if you realy struggle to get some pm me)

Another helpful tip, when you remove the clear poly pipe from the hot water to begin with use a pair of closed pilers and open them to "open" the end of the pipe to begin with. It's easier than trying to jam it on the recirc valve to begin with!

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 11:29 pm
by spree
Ah great, thats what I was thinking but I wasn't sure if others would see it that way. I'm just a bit paranoid lol.

I will have a go at supergluing my ICV mount back together then as it has split in the middle......

Thanks a lot for the info again!

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Aug 09, 2010 11:36 pm
by glasgowjim
spree if you need a replacement icv mount then pm me :D

Re: How to do a 710N recirc valve upgrade!

Posted: Wed Aug 11, 2010 11:01 pm
by spree
glasgowjim wrote:spree if you need a replacement icv mount then pm me :D
Ooh! Thanks mate! I will see how the superglue goes and then get back to you... :-D

Re: How to do a 710N recirc valve upgrade!

Posted: Thu Aug 12, 2010 5:47 am
by bbf
I bought a new ICV, it's not expencive. I works some years now, on a richmoded ecu.

Re: How to do a 710N recirc valve upgrade!

Posted: Tue Sep 28, 2010 8:51 am
by grafi
thanks for the info!

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Nov 19, 2012 8:19 am
by jamesy12345
Came across this old post :D :hopping:

I did the same as u spree - snapped the same piece off, also was a bit lost on how to replace the "evil valve" :twisted: cos Volvo don't seem to stock them any more

Great idea bkf, great write up, cheers!

Re: How to do a 710N recirc valve upgrade!

Posted: Mon Nov 19, 2012 8:27 am
by jamesy12345
....and just for anyone else who has spent some time searching through this forum for exactly this info....some 'keywords' to help locate this thread....

Part number of existing valve is 3466145-4 (at least for a 1993 turbo it is)

also known crankcase breather valve, connected to idle control valve!!

:shock:

Re: How to do a 710N recirc valve upgrade!

Posted: Fri Dec 07, 2012 12:05 pm
by jamesy12345
Here are some photos from my efforts...in centre of the second photo you can see the hard plastic pipe cut off just below the crankcase breather valve...

Image

Image

The evil valve....

Image

...and the new one, Gangam style! Yes pliers are recommended to get the 22 mm outside diameter PVC tubing onto the new VAG valve....I have some tubing spare if anyone needs it..

Image

Fitting the new valve.....

Image

My hose clips were crap so I made some sleeves from 22 mm inside diameter hose to protect the tubing. You can just about see one wrapped around the 22 mm OD hose in my fuzzy photo above. I also changed out the existing recirculation valve - btw you will need larger hose clips than 20 to 25 mm, try around 30. I didn't take any more pics as once its all back together there's not much to see!

:shock: :crazy:

Re: How to do a 710N recirc valve upgrade!

Posted: Sat May 04, 2013 12:40 pm
by r5b18ft
I've done this mod on my car but now it idles very low at about 600rpm :?

What should I do now please ?

Thanks,

David.

Re: How to do a 710N recirc valve upgrade!

Posted: Sat May 04, 2013 8:57 pm
by jamesy12345
Hi, I also have this problem on my K-reg car. I was actually thinking about this the other day....Robou once made a comment that the pressures are different here compared to the original location of the recirc valve, maybe an indication that this mod does not work. My idle was low before the work tho so I didn't worry about it so much.

Anyway, if your idle was not low prior to the work, this could be sign that our valve is stopping air flow to the engine even though the ICV is open. Two things I was going to check on my car: what happens when the multi-plug is disconnected from the ICV, and what happens with the ICV is given an unrestricted flow of air i.e. the 710N valve is removed from the location we are discussing. Depending on how you do this it could mean unfiltered air was passing into the engine so it should not be for a long time if so.

A third option of course is to fit a known good Volvo part, but these are pretty hard to come by now!! If anyone has any ideas please post up!!

Re: How to do a 710N recirc valve upgrade!

Posted: Sat May 04, 2013 9:06 pm
by jamesy12345
two more thoughts:

my idle is OK when warm, so probably my temp sensor is knackered. Do you know if yours is OK?

And...

Assuming that the above sensor is fine, if removing the valve fixes the problem, then probaby the answer for us is to fit a non-return valve in place of the V710N.....as recommend by Robou in the first place :). I didn't do this first off as I didn't find a suitable one.......

If removing the valve does not solve the idle and the temp sensor is good, then check/clean your ICV.

Hope that is some use, when I eventually do my own checks I will post up.

Re: How to do a 710N recirc valve upgrade!

Posted: Sun May 05, 2013 1:29 am
by jamesy12345
Hmmm.....are recirculation valves open during idle....?

http://books.google.co.uk/books?id=Raan ... le&f=false

The above link is talking about a 996 turbo.

Re: How to do a 710N recirc valve upgrade!

Posted: Sun May 05, 2013 1:34 am
by jamesy12345
Yes, yes they are...

http://www.dj-sures.com/GraphicFiles/Au ... harger.pdf

http://forums.evolutionm.net/engine-tur ... -tech.html

That's good I was getting worried there. So, David, check the vacuum/boost line going into the top of the 710N valve also.

Sorry for the long discussion with myself! :roll: Just learning here

Re: How to do a 710N recirc valve upgrade!

Posted: Sun May 05, 2013 10:00 am
by r5b18ft
yes it's definitely open... and the mod actually does make sense cos the valve is open only on idle due to the vacuum sucking it open (when air is needed for engine to idle correctly) and it's closed when the throttle is open and there's no need for that extra air

I tried disconnecting the ICV but it made no difference.. now I'm thinking that it might be faulty. Anyone knows how I can check if it's working ?

my temperature sensor was replaced with a new original Bosch item some months ago (and haven't used the car much since then), so I doubt it's gone wrong

this morning I increased the idle a little bit from the throttle body so that it idles at 850rpm when warm (when the coolant fan is on & off), now I'll let it cool off completely and start it up again to see how it idles when cold..

on a positive note at least now when I rev it up it goes back to idling at 850rpm without any hesitation (before it used to stutter a bit and the revs went down to about 1100 and slowly down to 850ish)