no boost

[adam280]

hi all. can anyone help i have no boost , ive changed the bcs and maf sensor. no engine light on. cant see any splits in pipes it revs and idles ok just so slow. no smoke either, would it smoke if the turbo was knackered? cheers

[bigrotch]

Have got a mbc, is it plumed in correctly ie swap vac pipes round

[adam280]

no mbc, completely standard apart from exhaust. i was driving along all fine and the next time i accelerated it was dead, it struggles to keep up with a transit.

[AndysR]

What sort of Volvo do you have?

[adam280]

sorry forgot to say. its a 1997 v70r

[merc85]

Sounds like the bcs is knackered, if you take the vac line off the actuator she should "boost"

BUT NEVER DO THIS WITHOUT A BOOST GAUGE AS SHE CAN/WILL BLOW if you dont let off the gas! if she boosts with the vac line off it will prove the bcs is knackered.

either fit a mbc or a new BCS valve.

If she still doesnt boost it could be a Duff actuator, or a torn recirc valve.

[M-R-P]

or a sticky waste gate, if it sticks in the open position, it feels fine till you go to accelerate then it goes dull.

[Dangerous Dave]

Perhaps the actuator arm has come off the pin on the wastegate?

Was it a sudden loss of boost?

[MoleT-5R]

I had no boost on my t5-r, checked everything and in the end it turned out the cat had collapsed, removed the cat and the boost returned immediately.

Quick test is to drop the exhaust off the turbo and see if goes any better

hope this is of help..

[Joolz_850R]

I had no boost on my t5-r, checked everything and in the end it turned out the cat had collapsed, removed the cat and the boost returned immediately.

Quick test is to drop the exhaust off the turbo and see if goes any better

hope this is of help..

Ill second that. Car drove lovely until I hit the rolling road and found I had 130HP!!! Took a while but dropped the cat off and it was mullered. Need to make sure you have no misfire also.

[adam280]

it wasnt sudden, i was on a 15 mile journey all ok for the first 10 just plodding along then went to floor it and it was gutless. ive double checked the pipes no splits that i can see or feel. i can slightly move the actuator rod backwards and fowards, should this be solid? i have already changed the bcs. thanks adam

[Dangerous Dave]

The actuator rod should move a little along its length and it should take some effort as it is spring loaded, but the rod shouldn't move side to side. When I say it takes some effort, if try to move the rod on my turbo I can only move it about about 5mm just using my finger and thumb.

[adam280]

the rod on the actuator is quite loose it moves side to side and up and down. i can move it about 7~8 mm. i cant see all the actuator because of the heat shield. will a normal t5 one fit the v70r? are they hard to fit

[Dangerous Dave]

Thats not right then, it should be fixed tight. You need to get the heatshield off to get a better look at the other end of the actuator rod, its only a few bolts and it slides out the way (no need to take it out from behind the engine). Its just a bit of a pain to get to one of the bolts down the water pump end of the engine.

It could possibly be as simple as the end has come off the actuator arm and just needs putting back on with a new locking pin.

[adam280]

hope so mate will check 2moro

[adam280]

Fitted my new actuator today and the car is just the same,just glad I didn't buy a new one. gonna have to check the cat.

[T5frankie]

Fitted my new actuator today and the car is just the same,just glad I didn't buy a new one. gonna have to check the cat.

with a knackered cat you will have some boost as joolz did but not enough, yours has no boost at all

[M-R-P]

starting to sound like a cracked turbo :eek:

[adam280]

Oh great, what's the best way to tell if the turbos knackered?

[adam280]

I forgot we put your gauge on it. It ain't looking good is it,could the recirc valve be leaking?
with a knackered cat you will have some boost as joolz did but not enough, yours has no boost at all

[M-R-P]

Take the turbo off and have a good look inside the exhaust housing. If it's cracked, You'll see. Try the recirc first tho, it's easier to do. I have a working one (off a 16t) if you need it.

[mitchyboy01]

Is it running like a tractor? Bottom boost hose come of intercooler??

[mitchyboy01]

Ignore that, I re read your original post and saw it's running ok doh

[T5frankie]

I forgot we put your gauge on it. It ain't looking good is it,could the recirc valve be leaking?
we didnt hear any air leaks anywhere

[T5frankie]

Is it running like a tractor? Bottom boost hose come of intercooler??

his car runs quiet and smooth and drives normal just with no boost

[M-R-P]

What sort of mileage/abuse are we looking at? could well be recirc.

[T5frankie]

and we tried my mbc on and still nothing

[adam280]

As frankie said runs ok just so slow, might try a blanking plate I've got a dump valve just gotta get a fitting kit

[Rudeyboy18]

Did you get a resolution of this fault Adam280?