T5R boost question / help please
 

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!

I cannot help with the boost issue, but just wanted to say glad you have found a car that appealed to you and hope you have many happy miles in it.

Thank you! More details to follow in another thread, but in theory it should be a joy. 99.9% original and has led a charmed life very little use over the last few years, however I just feel it's lacking 'oomph' so as I'm a newbie to the world of Volvo ownership I'm looking for some guidance.

I'm hoping it could be just ageing vacuum lines but if there are any other pointers then hopefully someone on here can help. Whilst the turbo gauge does show negative on the scale then just into the white on the dashboard, it doesn't feel like I think it should i.e. a good linear shove of power, or even an old school wallop of boost at around 3k.

Vacuum pipes, intercooler hoses...?

Anyone??:confused_smile:

Boost issue
 

You could really do with an accurate boost gauge and also as regards to lack of power it all depends on what you are comparing to. I have said before in previous posts that I find the standard T5 engine lazy especially compared to modern cars.
Once you have an accurate reading of the boost pressure firstly I would get back to basics check or better replace all the vacuum hoses and check all boost hoses intercooler ect for leaks I use a smoke Pro for this. I remember on my me7 v70r it was the wastegate control valve caused an issue where the car would be savagely quick then nearly no boost

I’ve ordered some replacement 5mm silicone pipe plus clips and I’ll replace the lines from the turbo to the turbo control valve (the thing with the coloured lines leading to it) although one of them seems to connect almost under the turbo which looks a cow to get at!
If that offers nothing then I’ll do the intercooler pipes.

I would have thought a T5-R with circa 240bhp would have a good shove when on boost.

One thing I noticed tonight, if I rev the car with the airbox lid lifted I can hear the turbo but there’s a momentary whistle briefly, not turbo whistle and actual as though a person were to whistle a short sharp “peep” as you blip the throttle. Is this an indication of a leak somewhere that is being voiced through the airbox lid??

All thoughts welcomed!!

Where does the turbo control valve take its electrical information from? Could it be faulty?

Evening fella.

You should really give the car a full stage zero from the off - sound like some of it may have already been done - but I'd still take it all apart again and check fitment / quality of parts used. You'd be surprised how wrong some folk get it.

Re boost, or lack of: check VAC lines and routing, check intercooler and charge pipework for splits/cracks - particularly at clamping points - then change the TCV ( boost control solenoid) it'll almost certainly be the original and often overlooked.

You also mention the turbo is new - check that the wastgate is set to release at the correct Psi- you'll need a mitivac or similar to check - and adjust rod length to suit boost pressure that you want to hold.

Also check hot side connections of new turbo- loose manifold studs or a wapping big crack in the manifold will knacker boost generation- escaping gasses- as will poor fitment to the downpipe (reducing backpressure,.although this would be less noticeable).

I'll dig out some factory settings info & post it up shortly.

Glad you tracked down your unicorn. Welcome to the R club.

Cheers Morgan

My 850R was poorly when I got it. The first thing I did was to add a second boost gauge for fault finding. Eventually, I'd replaced all the vac pipes and experienced full boost for the first time going up a hill in the rain :teeth_smile:

My dash gauge goes to about 4/5 into the white on stock boost, I get the fuel cut jerks if I try to go higher by tweaking the waste gate.

Vac line routing

http://www.volvohowto.com/volvo-850-...oses-diagrahm/

Wastegate adjustment - looking for 4-5psi from factory.

https://www.matthewsvolvosite.com/fo...ic.php?t=53189

If you remove the turbo air intake pipe it makes the the connection on the compressor housing you need a bit easier to get to I did mine recently