P0299

[n11prx]

Hi guys thanks for letting me join, ive made the move from ford to vauxhall and im loving the 2014 astra vxr ive got, but ive hit a problem if anyone can help? Everything was fine but when i put my foot down hard on bypass it goes into limp mode and the service car soon light comes on, anyone had the same or know what it is? I plugged it in and code is p0299
somebody mentioned boost solenoid on top of engine??
Thanks
jon

[Carbon Flash]

Hi, welcome to the forum, sorry to hear you have a problem..

As far as I am aware a P0299 for lack of expected boost pressure fault has not been a common problem on the J VXR.

Could be a boost control or turbo problem, but referring to the drawing at,

http://ci.catcar.info/opel_2015_05/data/P10/G147B.png

first thing I would check for with the engine turned off is for is any signs of boost pressure air leaks (with a torch and a mirror on a stick maybe) from seal 15 between the turbine flange and pipe 14, that the two Torx screws 16 on the pipe flange are not loose, for any leaks in the hose part way along pipe 14, the connector between pipe 14 and pipe 18, pipe 18 and the connector to the intercooler 19, the intercooler itself, and the connector from the intercooler to pipe 20, pipe 20 itself, and charge pressure sensor 21 and check that this sensor is fitted correctly and the wiring looks good. Other than that, the next thing might be to record the boost pressure on a test drive with a diagnostic tool and check out the results to see what pressure you are actually getting at various engine speeds and under enthusiastic acceleration etc.

[n11prx]

thanks for the reply, ive been trying various things for 3 days now and still goes into limp mode on bypass at higher revs;( new maf sensor,new boost solenoid, had the engine smoked and no leaks anywhere, even took intercooler off yesterday and had it pressure tested, all fine will check the turbo pressure next,
thanks for your help
do you know what sort of readings i should be getting?

[Carbon Flash]

Apologies, got confused by absolute pressures in my post yesterday, so have deleted my post yesterday and reposted.

Good to hear you have had it smoked, and the intercooler pressure tested.

To quote the original press release copied at,

http://www.vxronline.co.uk/forum/arc...t-183829.html?

‘The build-up of pressure starts as early as around 1400rpm. The maximum charge pressure has been increased to 1.5 bar – that represents a 25 per cent increase compared with the one used in the 2.0T Insignia. It was therefore necessary to make the turbocharger even tougher, more durable and able to withstand the increase in pressure.’

and yesterday I took my mine up a local hill for a warm up, and just before the end of a period of maximum acceleration with the throttle position reading 100% (Wide Open Throttle) at 60mph, engine speed 4,132rpm, inlet air temperature 20 Celsius, with the Turbocharger Bypass Solenoid Valve Command – Inactive, and the Turbocharger Wastegate Solenoid Command at 78%, with the desired boost shown as 237 - 265kPa, the maximum actual boost pressure it achieved for 2.5 seconds was 234-263 kPa, so the actual boost of 234- 263kPa [absolute] minus the indicated atmospheric barometric pressure at 93kPa [absolute], gives 141 - 170kPa, 1.4 - 1.7 bar if I have got my sums right this time, so around what Vauxhall quoted.

While the diagnostic tool helpfully graphs both the desired and actual boost pressure, what it does not say is how far adrift the actual boost has to be from the desired pressure to set a P0299 code, but a difference of 20kPa is commonly quoted such as in a TSB for a 1.4 engine at,

https://testing-public.carmd.com/Tsb...118578/4823048

with graphs on pages 11 and 12 showing normal and malfunctioning wastegate operation.

[n11prx]

i finally got to bottom of it, there is a boost solenoid on front but didn't realize there was one on the back of turbo, found a split in pipe, changed that and new boost solenoid and job done, pulling lovely in all gears now
thanks for the help and reply's

[Carbon Flash]

Thanks for the feedback, glad to hear you have got it fixed, have not heard of those pipes causing trouble before.