Turbo swap or new car, that is the question...

[Alex.]

Hi Guys,

A while back I had a lack of power problem with my Saffron 1999 C70 T5 GT, with a manual box - http://www.vpcuk.org/forums/showthre...-Boost-Problem
The last entry in the thread above I was about to change the TCV, that did not fix the problem.

Life got in the way and as the car was (still is) drivable, I put thoughts of top end power to the back of my mind.
Anyway, I had the chance to engage in a bit of diagnostic work with a local mechanic with a dyno and it does not look good.

The dyno chart looks like a normally aspirated engine, nice straight curve up to 177bhp. :-(
Boost pressure is only holding at 4 psi and there is some noticeable wear in one of the shafts. He did say that the engine itself feels good and strong, which is a bonus.
Something suggested as a possible problem is the standard dump valve, if the internal diaphragm is split then the boost pressure will not be held. I'm not familiar with the internal workings, but is this feasible?

So it is either the dump valve or turbo and I have a choice to make.
Do I take the opportunity to change cars to one with less problems? This car does have a few issues, I made the mistake of making a list... A replacement would probably be the newest, cleanest V40 I could find for a grand.

If I was to replace the turbo, where would I get one from?
I am reluctant to just buy a second hand unit with the doubt over whether it is sound and how long it would last. Where would I obtain a new or reconditioned unit, safe in the knowledge that it is not a cheap chinese knock off and will bolt straight on?

Then there is the option of sourcing a 19T rather than a 16T and using it as an excuse for a remap. Although that is further expense that I can't really afford...

I am conflicted!
It might come down to being able to source a reliable turbo to make this decision.

Alex.

[MaxTS]

Usually it is pretty obvious if a turbo is broken- there will be smoke or loud whining. Even then they still create boost, not far off what they should be creating!

Your's sounds like a boost leak or a wastegate issue.

Boost leaks usually leave a misting of oil around the leak. Common places are intercooler seal (where the ali bit meets the plastic tank) and Vac lines.

The other issue could be the diaphragm of the waste gate has a split in it causing it to not function properly and effectivly not work at all or as mentioned the BOV.

It really just needs some diagnosing as i bet it will be a really cheap fix!

[ExternalError]

if its only making 4psi I'd be looking for a boost leak, start with the main silicon hose connectors starting with the top of the turbo to the intercooler then the intercooler to the throttle body are on tight and there are no splits. If this hasn't resolved your issue see if you can get it smoke tested this will show any leaks like a split in the intercooler or any of the hard plastic pipework. that's the cheap diagnostics out the way after that its down to the scrappy for a replacement waste gate actuator and also a turbo off job to see if there's any issue with the waste gate itself

[MaxTS]

Also just think of how quick it would feel after the fix, you'd get another 70 odd bhp.

[claymore]

Yep, if you can't find an obvious boost leak I'd be looking at the recirc valve.

[Biff]

If you can't find a boost leak the cheapest way to change your re-circ is a blanking plate off eBay. £16 & will sound brilliant.

[Alex.]

You've all convinced me, I want to fix this car! So this Friday (first opportunity) I will be looking at the recirc valve.

If you can't find a boost leak the cheapest way to change your re-circ is a blanking plate off eBay. £16 & will sound brilliant.

Can I just replace the standard valve with one of these blanking plates and drive without a BOV?
I have been reading various sources that say it is fine to drive with just the blanking plate as the boost is not particularly high. Just to test the diagnosis, before replacing the faulty part.

Alex.

[martin_r_smith]

it will be fine to drive. It will also make lovely turbo fluttery noises to if thats to your liking.

[PNuT]

I always use some additional sealant on these blanking plates, I spent a lot of money & time looking for a boost leak because of one of those things a few years ago!

I would assume reading the other thread & the wastegate chirping when changing gear this is already referring to the fluttery noise anyway which would suggest the BOV isn't working correctly....

I would check the hose that feeds the BOV first....

I have a nearly brand new stock BOV in my garage

[Biff]

You've all convinced me, I want to fix this car! So this Friday (first opportunity) I will be looking at the recirc valve.



Can I just replace the standard valve with one of these blanking plates and drive without a BOV?
I have been reading various sources that say it is fine to drive with just the blanking plate as the boost is not particularly high. Just to test the diagnosis, before replacing the faulty part.

Alex.

I've run 2 cars now with blanking plates & no issues.
Mine were pre me7 (with a throttle cable not fly by wire like yours) although yours is me7 it may chuck the odd wobbler, not entirely sure as I've avoided the later models for the fussy behaviour they can show.
I know you can buy an uprated re-circ from forge motorsport should it give you a big headache.

[Biff]

I always use some additional sealant on these blanking plates, I spent a lot of money & time looking for a boost leak because of one of those things a few years ago!

I would assume reading the other thread & the wastegate chirping when changing gear this is already referring to the fluttery noise anyway which would suggest the BOV isn't working correctly....

I would check the hose that feeds the BOV first....

I have a nearly brand new stock BOV in my garage

I think he is referring to the re-circ as the dump valve as Volvo never fitted one as standard.

[Spawned66]

I've run 2 cars now with blanking plates & no issues.
Mine were pre me7 (with a throttle cable not fly by wire like yours) although yours is me7 it may chuck the odd wobbler, not entirely sure as I've avoided the later models for the fussy behaviour they can show.
I know you can buy an uprated re-circ from forge motorsport should it give you a big headache.

I have a 99 C70 ME7 and just have the Forge blanking plate on mine. No faults ever came up and like you said it does have the nice Chirping sound.

[PNuT]

Its one & the same thing... designed to release boost pressure & keep the turbo spinning rather than stalling which is what the fluttering noise is....

The one Volvo & Mitsubishi fit just recirculates the released air rather than venting it to the atmosphere

[Alex.]

Thanks guys,
I've ordered a blanking plate and will extract the dump/recirc valve soon and see what condition it is in. Although I'll probably just fit the plate if it is here in time!

PNuT, if it is the recirc valve, would you be interested in swapping your nearly new one for some pictures of the queen?

Alex.

[PNuT]

I am sure we can sort something out

[jamesy12345]

Even if it did need a new turbo, if the rest of the car is in good nick & you like it, replace the turbo & you will love it after that! Your car isn't common at all now, if you can find another one go for it! Otherwise fix it

But hope the fault is a minor one & it gets resolved to your liking

[Alex.]

Well it's not the dump valve. Replaced it with the blanking plate and there is no difference.
No extra acceleration and torque is still reporting the same boost pressure.

Anyone know a decent garage in the north kent area to do a smoke leak test?

Alex.

[M-R-P]

I wouldn't rely on torque to give you an accurate boost reading. Get yourself a proper gauge.

[stribo]

If there are no obvious leaks, I would be looking at the actuator (in fact I am, as I have the same problem with mine), if it's tired, it may be opening too early.

[PNuT]

I suppose I could send him one of those as well!