Turbo Egr Vsv

August 24, 2011

After 6 months of problems I've finally sorted the poor performance and lack of power over 3000 revs.

After the initial p1251 was fixed with some Halfords 10k boost it came back and was fixed with BG224 Fuel additive but she still lacked power and the question remained, why so much soft soot in the system?

SCV tested, fuel pressure tested, VSV ok. EGR cleaned and then replaced no improvement.

Still running rich causing excess soot in the system and a coked up EGR. Fuel filter replaced and new air filter fitted, no difference.

No fault codes at this point either.

Water temp sensor replaced in case the ECU was getting a message that the engine was always cold and therefore needed more fuel - hence the excess soot, no difference.

Air intake sensor removed cleaned and tested, all ok and no difference.

Removed the air filter to confirm running rich by allowing more air in and she runs fine!

The end of the air filter intake that clips to the valence near the radiator was missing it's 2 clips, it was missing one when we got the car.

Above 3000 rpm the plastic intake was lifting a little and as it is chamfered it was moving closer to the bonnet and gradually reducing air flow. With new clips in place she goes as she should and mpg is back above 50mpg. Found the old clips in the filter box!

The restricted air flow was probably the cause of running rich which was probably the cause of the EGR and Turbo coking up.

Feel stupid for not sussing this sooner but thought I'd share in case it saves someone the same hassle I've had!

August 24, 2011

Well spotted!

August 25, 2011

Feel stupid for not sussing this sooner but thought I'd share in case it saves someone the same hassle I've had!

Feel Stupid???? I don't think you have any right to be! :thumbsup:

Hind sight is an exact science. Most things seem obvious once you've found the solution.

I think you did well to work that one out.

February 25, 2012

Removed the air filter to confirm running rich by allowing more air in and she runs fine!
The end of the air filter intake that clips to the valence near the radiator was missing it's 2 clips, it was missing one when we got the car.
Above 3000 rpm the plastic intake was lifting a little and as it is chamfered it was moving closer to the bonnet and gradually reducing air flow. With new clips in place she goes as she should and mpg is back above 50mpg. Found the old clips in the filter box!
The restricted air flow was probably the cause of running rich which was probably the cause of the EGR and Turbo coking up.
Feel stupid for not sussing this sooner but thought I'd share in case it saves someone the same hassle I've had!

Well done for sorting it out. I am suprrised such a small obstruction like moving parts to cause the car running so rich and or restricting that much of air.

I recently got the same code P1251 Turbo/Super Charger Overboost Condition (Too High). I was on a straight bit of road and floored the pedal to clean the build up of my wife's school run driving. After a little hesitation it jolted back refusing to go any faster and droped running on 1/3 of the power. The Engine error light came up - P1251.

After restart it was OK, but everytime when I floor it, it hesitates and dips down, so I let go of the gas. At least I had normal power below 3000 revs or so.

I recently got the error check light cleared but the hesitation still happens at quick acceleration.

Sometimes when I drive the car and am a bit aggresive despite the hesitation it suddenly clears and the car runs perfect with plenty of power and most importantly no smoke at all. Well yes I did not mention the black soot that comes out when presed hard, but it suddenly disapeared when the hesitation got cleared. The next day, same thing still hesitates.

To sum it up, I think it is something sticking a valve or something similar within the Turbo or maybe even the EGR valve.

EGR valve was cleaned out a year ago, because of the smoking black soot. I made it so clean and the plunger moving smooth that I could sell it as new if I wanted. Did not resolve the problem.

I wonder if the EGR had its time despite its prestine condition.

Another consideration is, and I do not know how to name it other than the CAT that is close the the engine. I am saying that because it has another one further down the exhaust pipe. If the topmost is clogged up, offcourse the car would not be able to sustain high demand, high revs - hence more air. If the mixture gets way too rich there must be something to cut it back and if not then you see the huge amount of black smoke behind caused by richer mixture and unburnt diesel that turns into soot.

If you got lucky with the air intake, that is great, but for most of us still strugleling, the future seems ..... with possible expensive EGR, CAT or even I do not want to think about Turbo valve sticking.

February 25, 2012

yes sometimes we think the problem is deeper but it an opposite sometimes

February 25, 2012

After 6 months of problems I've finally sorted the poor performance and lack of power over 3000 revs.
After the initial p1251 was fixed with some halfords 10k boost it came back and was fixed with BG224 Fuel additive but she still lacked power and the question remained, why so much soft soot in the system?
SCV tested, fuel pressure tested, VSV ok. EGR cleaned and then replaced no improvement.
Still running rich causing excess soot in the system and a coked up EGR. Fuel filter replaced and new air filter fitted, no difference.
No fault codes at this point either.
Water temp sensor replaced in case the ECU was getting a message that the engine was always cold and therefore needed more fuel - hence the excess soot, no difference.
Air intake sensor removed cleaned and tested, all ok and no difference.
Removed the air filter to confirm running rich by allowing more air in and she runs fine!
The end of the air filter intake that clips to the valence near the radiator was missing it's 2 clips, it was missing one when we got the car.
Above 3000 rpm the plastic intake was lifting a little and as it is chamfered it was moving closer to the bonnet and gradually reducing air flow. With new clips in place she goes as she should and mpg is back above 50mpg. Found the old clips in the filter box!
The restricted air flow was probably the cause of running rich which was probably the cause of the EGR and Turbo coking up.
Feel stupid for not sussing this sooner but thought I'd share in case it saves someone the same hassle I've had!

Good heads up on this one! :drunk: