Loss of Boost

[blake]

Hi,

I've recently changed the Diverter Valve on my golf. Currently has Rev G one on from Awesomegti. Boost was great for the first week like driving a new car. The cars power has dropped back to how it was before the Diverter Valve change. I'm due to check it over again on my days off from work to see if i can see any obvious leaks etc.

I just wanted to check is it common for these Diverter Valves to split early? It's not had one replaced that i can see on the history so i assume that could come into play that now everything is having to work harder than when it wasn't boosting properly. Standard mk 5 gti no maps on it.

Thanks Blake

[Lucky ducky]

Your post is interesting as i too replaced my DV valve with a g version from awesome gti and have noticed a slight drop in power as well... we have put that down to the warm weather we have had recently... Although i have a lot more " pshhh " in between gear changes than I used to have dunno

[blake]

That's what i'd thought originally but feel like it's gradually getting worse.

[Lucky ducky]

Had a Rev D version in it but took it off.... Might put it back on at the weekend to see if there's a difference and have a look at the Rev G see if it's seals are done ... I'll let you know anyways

[blake]

Nice one, i'll keep you posted if i find anything on mine

[Wadgti]

I replaced mines last month. I used loctite on the 3 bolts as I read else where that the bolts will loosen up if only hand tight.

Im sure I seen a thread on some forum too where the guys new DV have blown back off as it was not tight enough. I would check to make sure if still tight to the turbo first.

I replaced my with rev g and can barley hear the turbo spool now under load where as before where the dv was ripped - the spool noise was lovely.

[Lucky ducky]

Thanks for the info wadgti.... Will have a look at the weekend cheers

[blake]

Just an update, DV was fine when i took it off, i never actually used loctite but they weren't loose when i came to check. My hose to the intercooler had quite abit of oil around the join and the clip wasn't that tight. I've tightened the clip and made sure the join was good, boost seems to be holding better than before now but i guess i'll see over next few weeks.

Cheers for heads up with loctite i'll take them out at some point and put some on just to make sure 

[muff1991]

As I was reading these posts, I was thinking.. boost leak.. yep, probs boost leak. probs the intercooler joins. and boom @blake hits it.

most leaks are usually at the crappy boost pipe joins (intercooler joins) this is the reason a lot of people (myself will be included soon) switch to the upgraded Audi S3 intercooler. as it eliminates the crappy joins and you can simply wind the pipes on with a Jubiliee or V band clamp. I actually read somewhere a long time ago, someone had actually Ali welded the whole lot.. boost leaks gone forever lol

I Agree with you though Blake, you'll probs find that after fitting the new DV everything else which has worn a bit over time has suddenly took a wack from the extra power!

[blake]

@muff1991 it's normally a new hose i'm assuming if its starting to leak from there if you're not going to swap the intercooler out?

Yeah it was running on original DV that i could tell after 85000, the old one came out in pieces so everything else has probably had an easy how ever many miles without it holding proper boost haha.

[muff1991]

@muff1991 it's normally a new hose i'm assuming if its starting to leak from there if you're not going to swap the intercooler out?

Yeah it was running on original DV that i could tell after 85000, the old one came out in pieces so everything else has probably had an easy how ever many miles without it holding proper boost haha.

Haha, yeah if that was original then boy it’s had a hard time lol.

Well yeah, most the time you can just buy a new pipe or new seal and clip and get away with it. But a lot of time due to the age of these cars now, the pipes have been on and off for various reasons, wiggles around loads over time of use, and it can actually wear the plastic housing that the pipe and clip goes into, which is why most just replace the intercooler for the much more substantial one!

I done a good little trick on mine not long ago, and that was... remove the pipe, carefully peel the seal off, wrap PTFE tape (plumbers tape) in the groove where the seal goes “padding it out” and then place the seal back on over the tape. Grease the seal we’ll and slide it back in, making sure you haven’t padded it too much otherwise it’ll try peeling itself off when pushing the pipe back in. Make sure it fits perfectly snug! Wack the clip in and that seemed to help seal mine quite well tbh. Just a little idea of yours got bad and you didn’t want to spend out on a pipe. A lot of people do replace the pipe too as the metal lugs the clips slides between to hold the pipe on... they wear down too! It’s a stupidly crap design if you ask me... and you can’t beat a simple slide over and clamp down design you get on the s3 intercooler etc! Hope it all holds out for you mate. :-)


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[blake]

Ah cool thanks for the tip, i'll keep my eye on it over the next few weeks. Much appreciated!