Engine: 2.3 F/Inj Purge check valve needed

[Luxobarge]

Hi all - car is 1997 V70 T5

Yesterday I was going over the vacuum lines and replacing the TCV to chase a problem with lack of urge from the turbo, I'm not the only one with this problem on here at the moment eh?

I checked all the vac lines and replaced where they were crusty, and I found that the one-way valve at the front was faulty, I can blow air through it easily in both directions. This is the little mushroom-shaped in-line valve that sits on top of the radiator fan cowling, with a short vacuum line that goes into the left hand side of the inlet manifold (right as you look at the front of the car) and the other side of it goes into a larger vacuum line that goes towards the battery and into the purge system.

Looking at the Volvo vacuum diagrams for this engine it actually appears that there are two of these valves, I haven't located and tested the other one yet.

It appears to have a part number stamped on it 00194-031 but googling this comes up with nothing remotely like any kind of check valve. I called FRF Volvo and they can't find the part on their system either, which is quite a surprise, and somewhat worrying.

So:
a) can anyone confirm this part number or advise the right number?
b) any bright ideas as to where I can get one? Anyone have one spare? Anybody breaking a car with a good one on it? It's very easy to test if it's working!

Not sure this will have a great bearing on the running of the car, but it can't be right and I'd like to eliminate all faulty components whether they are directly relevant or not.

Thanks!

[downstream]

Is this what you're looking at?

https://www.skandix.de/en/spare-part...ction/1044361/

If it's just a one-way valve, any generic check valve off ebay would probably do? Presumably its job is to prevent boost from leaking away from the manifold and into the evap system...

[Luxobarge]

Originally Posted by downstream

Is this what you're looking at?

https://www.skandix.de/en/spare-part...ction/1044361/

If it's just a one-way valve, any generic check valve off ebay would probably do? Presumably its job is to prevent boost from leaking away from the manifold and into the evap system...

Thanks. Yes, that's the part all right, but at around £100 PLUS shipping from Germany I think I'll pass - and it's not even in stock!

Agree, a generic item would probably work just fine, I'm looking at that. Only snag is that on the original item the hose going into it and the hose coming out of it are two different diameters, and I can't find any like that. However, it's only fairly low pressure vacuum, so I'm sure I can invent a way of getting the hoses to mate with it OK.

Thanks again!

[Pupbelly]

Originally Posted by Luxobarge

Hi all - car is 1997 V70 T5

Yesterday I was going over the vacuum lines and replacing the TCV to chase a problem with lack of urge from the turbo, I'm not the only one with this problem on here at the moment eh?

Oh Luxobarge welcome to my chuffin' world! I'm really getting cheesed off with it now, I didn't buy my T5R to have a fat lazy estate and desperate to wake the the thing up.

If you get any joy please let me know. Mine went in for it to be looked at on Friday but due to low petrol and a total absence of getting any my garage bloke couldn't take it out to do any trials or live data from the ODB2 so apart from new discs and pads I'm no further forward!

[Luxobarge]

Hi Pupbelly - yeah, of course I will do, and please could you do likewise. Mine's not too bad, but I do remember when I got it that it would spin the wheels in the wet at full chat, and now it's quite a long way off doing that.

FRF have confirmed that they can't supply the purge check valve, but I've got a "generic" one coming in the post so I'll see if I can get that to fit and report back if it makes any difference. If not then at some point I'm going to get a bit more up close and personal with the turbo - all the vacuum lines are in great condition apart from the one that comes from the TCV and disappears under the turbo, that one is really crusty. It looks a pig to get at but I'll have a good go at some point, and probably also check/replace the TRV, or at least the diaphragm on it.

I really need to have a better understanding of how these turbos work, and what all the various bits actually do, so further help from this forum is going to be very much appreciated!

Cheers all

[Pupbelly]

Fingers crossed Luxobarge, I can't even get my TRACS light to flicker in the wet with a hoof full of throttle
The vacuum line to the bit under the turbo is a bit challenging but I got to mine by stripping out the plastic intake tubing from the airbox etc. and with a bit of stretching it is doable. Tightening a jubilee clip is great fun down there!

If that purge valve works then happy days, if not I think we're both back to the drawing board. I have gone as far as I can with my understanding so far. I wonder if there is some electronic input to the turbo control solenoid or something that is holding things back but I'm no electrician and I don't have the kit to be testing things. I can only assume it takes values from airflow, knock sensor, coolant temperature, throttle position....??

I'm sure I've checked the analogue mechanical side of things but it can only be something simple, its just a case of what!

[Luxobarge]

OK, update - the generic one-way check valves arrived today, so fitted it. It's got 8mm barbed connections on both sides, unfortunately the original Volvo one is 8mm on one side and around 11-12mm on the other, so I slipped a short piece of suitable fuel pipe over the connector to increase the diameter and secured with a 12-13mm pipe clip which works just fine.

Has it made a difference? Well, with a bootful of throttle the car certainly gets a move on and accelerates quite smartly, just not as full-on quick as I'd expect, certainly not going to spin wheels even in the wet. So I suspect it's still a bit lazy? Further things to do are:

1) Look for the other purge check valve and test/replace it as well. I think I need to take some intake ducting apart to get at it, but I know it's got to be down there somewhere, unless my vacuum diagrams are wrong. No big deal, but I'd like to eliminate it from inquiries, as they say. These check valves are there for a reason, and my philosophy is that if they're not working, then replace them - they're childishly easy to test after all!

2) Fit a temporary boost gauge. Being a V70 it doesn't have one, and mine is at the stage where I'm not totally convinced I have a problem, and if I do, how much boost I'm actually missing, so I'd like a gauge to actually measure what's going on. Can anybody tell me a good place in the engine to connect it to? The vacuum tree?

3) Replace the remaining crusty vacuum pipe that goes from the TCV to under the turbo - Pupbelly, I get how removing the fresh air intake pipe would help with access to this, can you advise how this comes off at the turbo end? Alternatively I'm having the car up in the air in the next few days so might see if there's any access from underneath?

4) If the above doesn't work and a boost gauge tells me I definitely am missing boost, I think I'm into checking/replacing TRVs and wastegates etc. - can anybody advise regarding access to remove these? Is this a case of removing the turbo? Or part of it?

All help gratefully received, including of course any more bright ideas for getting the boost side of things at least as good as Volvo intended.

Cheers!

[sdg1970]

I replaced both my one way valves with generic ones off Ebay (size I can't remember) and fitted oversize silicone vac pipes on one side. No problems over 2 years on.

I also fitted a boost gauge with the feed coming off the vac tree and the pipe fed through the drivers side bulkhead (throttle port). All good.

I also replaced my TRV with a Forge Motorsport uprated version, as opposed to blanking it off. I've never heard of waste gate problems with these, but it's possible I guess. I also replaced ALL boost hoses (assuming you haven't??) and main airbox intake to turbo hose. Check throttle body hose especially - it's very susceptible!

Funnily enough I'm fitting new heater pipes/matrix tomorrow to mine, so any pics you need I'll be in a position to do it. Any advice on matrix replacement appreciated....

[sdg1970]

Originally Posted by Luxobarge

I get how removing the fresh air intake pipe would help with access to this, can you advise how this comes off at the turbo end?


Cheers!

Easy. Remove air box, then unplug the two pipes off the bottom of the intake pipe. One is PCV related, the other is a very small vac (white pipe on mine) line. Then it's just a small 7mm socket and ratchet to unscrew the jubilee clip, or use a very extra long screw driver on it. Basically it's just connected at the turbo end via a jubilee clip, though likely if the pipe hasn't been replaced before it will be worn/heat scorched on that end. Mine is a 1997 and when I inspected it 3 years back it needed replacing. Volvo only part as I recall??

[SteveSarre]

Hi Luxo,

Hope I am not stating the obvious .. and maybe I am remembering something incorrectly.

OK you got the generic check valves. I think I shopped around on ebay and eventually found one that was the same (approximately right) thickness on both ends.

Obviously make sure you put it the right way round.

Make sure no vacuum hoses are perished or leaking.

Make sure the vacuum hoses run to the correct destinations. I colour coded the ends of my hoses (and refreshed the colours on the TCV).

As I understand it the TCV keeps the boost *down* - ie it prevents overboost in certain throttle situations. Maybe other stuff as well.

Does your TCV operate (electrically switch the vacuum on and off to the various outlets/inlets) as expected? Off the car, you can test it yourself by applying an appropriate voltage, sucking and seeing that the unit switches the ports open and closed as desired.

It has been a year or so since I last spent time on mine (1998 T5 and 1999 AWD etc). There are a couple of different TCVs out there. What part number is yours?
Is it this one?
https://www.volvopartswebstore.com/p...5/9155936.html
Pierburg make good ones.

Having found one failed check valve, I went around and checked all the others and found about 50% were bad, so it is an often overlooked item. I also found some good and some bad TCVs.

HTH
Steve