Turbo stopped spinning up??

[Marshy]

New poster! (less than 10 posts)

Right chaps, bit of an odd one here, fairly new to the world of turbo's although can't seem to get an answer to what might be wrong.

I have a T25 on my 5, engine wise it's standard apart from RAM kit and Scorpion exhaust, when I bought the car it was pushing 18psi quite comfortably and I had no problems with it. After a few months (4 maybe) I started to lose boost which I put down to a faulty actuator due to finding zero boost leaks anywhere. Anyways to cut a long storey short it eventually dropped to 6psi, put a new actuator on and it still wasn't boosting past 6psi.

I took it off the other day and put a T2 on and bam, I've got boost straight away. I've had a good look over the turbo, waste mechanism seems to work just fine, there's no cracks in the housing and there's bugger all play in the vanes, maybe 1mm side to side at a push. It wasn't smoking either. I've attached a couple of pics below so you can see the condition of the housings/vanes but at the moment I'm really at a loss.

I've no idea what may cause it (being a turbo n00b and all that) but I genuinely can't see what might be causing the problems.....

[Woznaldo]

How easily does the turbo shaft spin by hand?

Have you been letting the engine and turbo cool down after a hard run before turning off?

When the last time you changed the engine oil?

Are you getting full range throttle movement?

[Alastair]

Answer Woz and take some pics of your actuator set up too mate, then we might be able to answer!

[Marshy]

New poster! (less than 10 posts)

How easily does the turbo shaft spin by hand?

Have you been letting the engine and turbo cool down after a hard run before turning off?

When the last time you changed the engine oil?

Are you getting full range throttle movement?

Right, turbo shaft spins easily, video here of it, doesn't seem to take any effort, that's me just flicking it with my finger.

It very rarely gets driven in anger, but on the odd occasion it does it gets plenty of time to cool down. I was using the car as a daily so most days it didn't see anything over 40mph due to traffic....

Oil was changed late June and again last weekend just in case that was the issue.

Full range throttle movement is fine too, no problems there.

Here's the pics of the actuator set up, it's only in place loosely in the pics due to me checking out the movement of the wastegate by hand. Lock wired in place as I managed to lose the damn clip.... Actuator was bought off Blunty and sold as a working unit off a car that was holding 20psi.

[GTphil]

Have you tried a differant actuator, with what you have said, the turbo appears to be fine, so strange that you put a differant blower on and it boosted fine so that rules out the car being at fault. I think these actuators have a habit of failing. Worth a shot;-)

[Markey Mark (BD)]

How much preload is on the actuator? How much you have to pull it to fit on the tap?

[5teve L]

Did you loosen the nut on the actuator or is that how it came off ?
I ask as it's loose.

*Edit... Teach me to skim read, just seen you loosened it

[V Man]

I had an actuator like that many years ago and there was a diaphragm inside that had split. I think if you use an allen key you can take the front off and have a look?

[Marshy]

New poster! (less than 10 posts)

Right, actuator gives plenty of resistance when hooking it up. I only bought this one because I thought the problem was with the old actuator. Some of the tests that we've done are driving it without the actuator pipe attached so that any boost can't activate it, still nothing and taking the turbo-intercooler boost pipe off and checked the pressure of the air coming out, which was positively asthmatic. When we did the same thing on the Landy my hand was physically forced away.

[Woznaldo]

Marshy, it sounds like you've carried out all reasonable checks. I'd be taking the turbo to a specialist to make sure something internal isn't amiss.

Not sure who you've got in your neck of the woods? Might have to hit the mainland....

[Marshy]

New poster! (less than 10 posts)

Marshy, it sounds like you've carried out all reasonable checks. I'd be taking the turbo to a specialist to make sure something internal isn't amiss.

Not sure who you've got in your neck of the woods? Might have to hit the mainland....

Yeah looks that way, best get saving some pennies then....builders and concrete to pay for first