T5R boost question / help please

[Pupbelly]

Originally Posted by Pupbelly

I was curious as to what the turbo control valve was so decided to saw one in half to gain an understanding. I can’t upload the photos from my phone so I’ll try from work tomorrow for my laptop but it seems to be a magnetic type gadget but to be honest I’m none the wiser how it works!
I thought it would be a diaphragmed valve or something but it’s far from that.
Pics now below:

https://photos.app.goo.gl/MSN5uWSqtmZ8g9gT6

https://photos.app.goo.gl/jFCX3ezNxXnpueCV7

https://photos.app.goo.gl/3UGQxhEmhm5nCERN9

https://photos.app.goo.gl/4J29WD5kieMujsug9

Can't seem to get actual photos, hope the links work ok!

[s1monc]

Originally Posted by Pupbelly

What level of boost should be displayed on the stock boost gauge under full boost?

The needle on my car goes about 1/4 into the white section, and there doesn't feel to be the surge of power I would expect. Are there any obvious things I can check? I've looked at the lines from the turbo to the TCV and everything is now connected (the blue line to the fresh air link wasn't connected at the tree ). The hoses do feel a bit crumbly on all three so could there be a boost issue there as a result?

It doesn't feel as urgent as I think it should, so any advice would be welcomed.

Many thanks

Mark

This is a recent purchase (two days old!) so I'm still learning the quirks of the car. It has near full history. Recent turbo rebuild, and the PCV has just been done. Looking for guidance please as I learn to hopefully gain trust in it!

Hi Mark, I’m in Canterbury, not sure if that’s far from you as I see you are in Kent. I’ve got x2 manual T-5Rs and it took a while to trace boost leaks on one of them. Deffo buy a boost gauge even if it’s just for testing purposes, much easier to work out what’s going on. Both mine are slightly modded. Also got an F80 M3 as I like the old and new.

Your welcome to come over if you want to have a drive of either of mine to compare to yours in how it feels/goes.

Cheers
Simon

[Pupbelly]

Originally Posted by s1monc

Hi Mark, I’m in Canterbury, not sure if that’s far from you as I see you are in Kent. I’ve got x2 manual T-5Rs and it took a while to trace boost leaks on one of them. Deffo buy a boost gauge even if it’s just for testing purposes, much easier to work out what’s going on. Both mine are slightly modded. Also got an F80 M3 as I like the old and new.

Your welcome to come over if you want to have a drive of either of mine to compare to yours in how it feels/goes.

Cheers
Simon

Hi Simon, appreciate that, I'm in Maidstone so not a million miles away. The replacement boost control valve has arrived today so hoping that is the root of all the slugishness. I'd like to think I've been over most of the hoses apart from the main intercooler pipes tucked away at the bottom of the radiator area.

What were the problematic areas on your boost wise?

It'll probably be the weekend before I get to have a proper play with mine but I'll post any updates here and keep those that are interested in the know.

Thanks again

[Cypher007]

any fault codes in the ECU's. they can be read out under the bonnet.

[Pupbelly]

Originally Posted by Cypher007

any fault codes in the ECU's. they can be read out under the bonnet.

Admittedly I’ve not done that yet which could be a daft move. There is an OBD2 socket and that shows not codes but not sure if that give a full diagnostic?

I’ve not sussed out the under bonnet diagnostics thing yet so that may be a route to look at. Just checked, don’t think there is an under bonnet diagnostic box - because it’s got OBD??

I’ve just fitted a brand new boost control valve this evening but not started the car or taken it for a drive yet as we’ve got stuff on tonight. I’ll take it to work tomorrow and see if anything has changed.

[Pupbelly]

Couldn’t wait so just been out. No different FFS!! Boost gauge only just tickling into the white zone, plenty of vacuum when not on the throttle.

There’s no surge no sound of any turbo spool, no oomph, just a lazy 2.3. What’s going on??

Vacuum lines to (new) turbo control valve all correctly fitted with clamps.

What else can be holding the car back? Is it a case of checking intercooler hoses or are there other vacuum lines that will influence things?

I need some turbo input!!

Anyone??

[s1monc]

If it’s idling ok and you are pulling a good vacuum I’d check the actuator, you could shorten the arm a bit but would at least need a proper boost gauge to see what it’s boosting at. It’s quite easy to bend a conrod on these with too much low down torque.

[Pupbelly]

The idle is good and stable and the vacuum (according to the stock gauge) is good too.

There seems to be no boost. I don’t fancy messing with the actuator and causing damage.

Where does the TRV pipe work go? Could that be at fault?

[Baffler]

Originally Posted by Pupbelly

Couldn’t wait so just been out. No different FFS!! Boost gauge only just tickling into the white zone, plenty of vacuum when not on the throttle.

There’s no surge no sound of any turbo spool, no oomph, just a lazy 2.3. What’s going on??

Vacuum lines to (new) turbo control valve all correctly fitted with clamps.

What else can be holding the car back? Is it a case of checking intercooler hoses or are there other vacuum lines that will influence things?

I need some turbo input!!

Anyone??

If the intercooler and or the boost hoses were damaged the chances are you'd struggle to start it not to mind drive it.

How sure are you that the vacuum lines from the TCV to the turbo are in the correct order? Did you work off a diagram or replace like for like as they may have been incorrectly fitted prior to your purchase.

Is the new valve colour coded or marked e.g. yellow to wastegate, red to compressor housing, blue to fresh air.

[Pupbelly]

Originally Posted by Baffler

If the intercooler and or the boost hoses were damaged the chances are you'd struggle to start it not to mind drive it.

How sure are you that the vacuum lines from the TCV to the turbo are in the correct order? Did you work off a diagram or replace like for like as they may have been incorrectly fitted prior to your purchase.

Is the new valve colour coded or marked e.g. yellow to wastegate, red to compressor housing, blue to fresh air.

The car starts and idles fine and ticks over nicely too. The new 7.28197.16.0 Pierburg had red/yellow/blue ports marked on it and I replaced as per the old control valve, but routed as you say, yellow to wastegate, red to compressor and blue to the air intake. Plugged in just fine, and did a gentle drive with a few foot down moments to help the car to "learn" although mine seems to be not wanting to learn bugger all.

I'm erring towards changing the BCV diaphragm next, but I'm going to ring Owen Developments who did some turbo work according to the receipts in the middle of last year to establish just what they did. The BCV looks shiny and new so could already have been changed