Hello.
Just wondering if anyone here has ever had their TDi 405 kind of "lag" when the boost is up between 2750-3750rpm?
Quite often, maybe 75% of the time when I accelerate hard while overtaking or out of a roundabout, I get a slight drop in acceleration as the rpm needle goes through the power-band.
Sometimes it's a second drop, almost like someone has pulled up the handbrake suddenly for a second, and other times it pauses and sounds like it's not right, and stays low on power until I change gear and re-apply the throttle, or lift off for a second, and press my foot down again!
In general driving though it seems strong and responsive, just when you want to get the power down and use all the rpm's it's a bit stuttery/pausing.
Really weird.
I've had the car about 6 months, and done about 14000 miles, half of that motorway. In general it's been a great car... had a few problems with on the limit oversteer (think it was the tyres bedding in), and the radiator went, but a new radiator, thermostat, engine mounts, gear linkages, brake discs and pads, clutch cable, and it all seems to be great except for this funny power delivery!
It just seems to be getting worse with time...
I'm fearing it's the turbo wastegate sticking open or something similar, since off-boost and around the lower rpm it drives great, so I think the fuel pump is ok!
Any ideas or help would be much appreciated!
Cheers
Dave
405 Tdi (96 N plate) turbo lag?
Moderator: RichardW
Just to add, several times the turbo has been allowed to boost to the atmospehere... I assumed this would mean the turbo having no pressure at pressure side would not actuate the wastegate, so the turbo would over-spin.
To be really honest, the first time it happened was where the pipe comes up to meet the intercooler, where the jubilee clip was loose. Drove for maybe 3 miles home steady away like that.
The second time was for about 2 miles home, and it popped off the turbo compressor end directly... Again, I drove steady away!
Thinking it's maybe the wastegate, is there a way I can test it's working right? Testing the pressure somehow?
Would a failing wastegate/turbo cause the above symptoms?
Again, thanks for any ideas or help!!!
Cheers
Dave
To be really honest, the first time it happened was where the pipe comes up to meet the intercooler, where the jubilee clip was loose. Drove for maybe 3 miles home steady away like that.
The second time was for about 2 miles home, and it popped off the turbo compressor end directly... Again, I drove steady away!
Thinking it's maybe the wastegate, is there a way I can test it's working right? Testing the pressure somehow?
Would a failing wastegate/turbo cause the above symptoms?
Again, thanks for any ideas or help!!!
Cheers
Dave