850 t5 r turbo problems

Nicholls39 · Post by **Nicholls39** » 07 Feb 2020, 12:46

Hello everyone
Turbo gauge wont pass more than 3/4 of the way around when accelerating. The car also starts to accelerate fast then surges almost like its hitting a limiter.
First component to look at?

I've not had the car long so dont know what has been replaced in its history.

Any advice would be massively appreciated

Cheers in advance.

Post by **Sveedy** » 07 Feb 2020, 19:02

I think I'd first check your rubber intercooler hoses. I've heard that when they get old and soft, they will partially collapse when the turbo kicks in, basically clogging everything up.

Post by **jreed** » 08 Feb 2020, 06:23

I agree with the above advice. In addition, it might be a good idea to check all the rubber vacuum lines, in particular those connecting to the boost control solenoid / turbo control valve.

Post by **erikv11** » 08 Feb 2020, 15:35

And if those checks don't solve the problem, check the CBV diaphragm for tears, especially if it's never been changed. I actually might even look here first if it wasn't such a PITA to check. The hoses are easy and should definitely be inspected.

magna224 · Post by **magna224** » 09 Feb 2020, 01:56

I was under the impression that 3/4 was how far it is supposed to go on a stock car. Is that not correct?

Post by **Clemens** » 10 Feb 2020, 14:24

Worn ignition components can cause that. Are your sparkplugs, wires, distributor and cap OEM quality and pretty newish? if not, this can cause erratic behaviour like you mentioned.