Smoke test on the vacuum system turned out fine. Garage did some further diagnostics and noted a wiring issue near the turbo / wastegate. A wiring repair was done in the past and it appears this was not done that great back then.
The wiring repair done by the current garage made no difference and engine is still flat spotting. They now are asking me where I want to go with this given the amount of time they might have to spend finding a potential wiring issue versus the value / age of the car.
Was OK (up to about 60mph anyway) until I got the airbox electrovalve fitted. A £50 part which seems to have caused all this apparently Edit to add: even bought another airbox electrovalve and got that fitted...same issue (that was fitted along with a new swirl flap electrovalve)
N75 valve on 2.2 DW12 2.2 HDi engine
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Re: N75 valve on 2.2 DW12 2.2 HDi engine
2003, '03' 406 Executive 2.2hdi 136.
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Re: N75 valve on 2.2 DW12 2.2 HDi engine
Are there any fault codes that pop up when the car flat-spots?
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
Re: N75 valve on 2.2 DW12 2.2 HDi engine
Hi
No fault codes appear when the engine flat spots.
Thanks
No fault codes appear when the engine flat spots.
Thanks
2003, '03' 406 Executive 2.2hdi 136.
-
- 3.0 24v
- Posts: 3575
- Joined: Fri Apr 06, 2012 9:02 pm
- Location: Bournemouth
Re: N75 valve on 2.2 DW12 2.2 HDi engine
Hmm, okay - I'm starting to clutch at straws now..
If the vacuum system is okay ( not sure what a smoke test is and how this works ) and the swirl flap diaphragm is good, then it could be the pipes are the wrong way round.
The swirl rod should pull back the little ball/socket affair on the top right of the engine when it's ticking over, and push it forwards when the engine is revved over 2100rpm - if this is reversed then half the valves are closed when they should be open at higher revs.
As far as I know, and I'm no expert, but the solenoid on the airbox diverts vacuum to the air dosers on the front of the engine, either a cold air feed from the intercooler, or the warmer air from the hot water jacket tucked behind the radiator - I guess if these are the wrong way round then the engine isn't getting the cold intercooled air which would affect performance.
Also, the turbo has no wiring connected ( I don't think ) so I'm not sure what wiring was damaged, but a repair wouldn't have done any harm I suppose....
New fuel filter maybe?
Sadly, I don't know how many things to suggest - it's all time and money which is hard to justify on an older car
If the vacuum system is okay ( not sure what a smoke test is and how this works ) and the swirl flap diaphragm is good, then it could be the pipes are the wrong way round.
The swirl rod should pull back the little ball/socket affair on the top right of the engine when it's ticking over, and push it forwards when the engine is revved over 2100rpm - if this is reversed then half the valves are closed when they should be open at higher revs.
As far as I know, and I'm no expert, but the solenoid on the airbox diverts vacuum to the air dosers on the front of the engine, either a cold air feed from the intercooler, or the warmer air from the hot water jacket tucked behind the radiator - I guess if these are the wrong way round then the engine isn't getting the cold intercooled air which would affect performance.
Also, the turbo has no wiring connected ( I don't think ) so I'm not sure what wiring was damaged, but a repair wouldn't have done any harm I suppose....
New fuel filter maybe?
Sadly, I don't know how many things to suggest - it's all time and money which is hard to justify on an older car
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
Re: N75 valve on 2.2 DW12 2.2 HDi engine
Hi
Interesting what you say there about cold air getting to the engine as at 60mph plus (colder air being presented to the engine) there are no flat spots, but at lower speeds there is.
Interesting what you say there about cold air getting to the engine as at 60mph plus (colder air being presented to the engine) there are no flat spots, but at lower speeds there is.
2003, '03' 406 Executive 2.2hdi 136.
Re: N75 valve on 2.2 DW12 2.2 HDi engine
Changed the swirl flap diaghpram and that improved things a bit in terms of no smoke. Still getting flat spots. One other part I am looking at that may be the issue is part no. 1920.GH - intake manifold pressure sensor. Is it worth changing that?
2003, '03' 406 Executive 2.2hdi 136.
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- Mod with a 2.2 HDi, De-Fapped!
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Re: N75 valve on 2.2 DW12 2.2 HDi engine
Never known one to go wrong, but I have seen leaks in that area or even the sensor tube broken away from the intercooler in one case.
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
Re: N75 valve on 2.2 DW12 2.2 HDi engine
My 2,2 has a variable vane turbo. It was very sluggish when I got it. Checked everything as you have done with no improvement. Decided to check the turbo so removed it. Found the variable vane system was very sticky due to a buildup of fine carbon? on the vane system. Cleaned it all off, made sure the variable vane was free moving, replaced the turbo and problem solved.
Serial 406hdi licker
Re: N75 valve on 2.2 DW12 2.2 HDi engine
What is the difference between 1628.LQ and 1628.HC valves and is it possible to use 1628.LQ in place of HC?