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EGR Blanking plate on Diesels

23K views 23 replies 10 participants last post by  robertsmith 
#1 ·
Anyone fitted an EGR blanking plate to the inlet of their EGR valve on a diesel engine?
I did on my Meriva B with the 1.7 engine, planning to do the same with my Mokka 1.7.
Any feedback?

I also used to add a small amount of 2 stroke oil to the Meriva as well as using Shell V Power diesel.
This certainly made the engine quieter first thing on a cold morning.
So far the Mokka has only slightly better fuel consumption (48mpg) than the Meriva B (46mpg), so hoping to improve this to get above 50mpg.
 
#4 ·
Hi Mark,
the project stalled because of the lack of space between the EGR valve and in the input pipe from the exhaust. The ERG blanking has be 3mm thick (or it vibrates like a drum) but fitting it moves the EGR valve forward which leads to a leak on the output of the EGR valve, which is where the fresh air going into the engine.
I can post some photo's later.
 
#6 ·
It might just be my car, it is a lot of trouble to get to the allen headed screws at the other end of the orange/rusty pipe, I would need to remove a 75mm diameter plastic pipe.
If I could get to the allen headed screws at the other end of the orange/rusty pipe and get the screws undone then I might be able to swivel the orange/rusty pipe just enough to allow the insertion of the EGR blank.
In the photo the EGR valve has been moved so you can see the EGR valve output and the mating surfaces need to be very accurately aligned or you get an air leak.
The opening shown is the air pipe after the turbo where the exhaust gases are added to the fresh air.





Edited by: TonyP2020
 
#8 ·
When the blanking would not fit (and it does have a hole in it), I had a 'phone chat with the guy who makes them.
He explained that when the exhaust gases reach the blanking plug it is a series of pulses.
He said that a thin plate moves in time with the pulses (thimpaning, I think he called it) and a thin plate suffers metal fatigue and fails and bits get sucked into the engine.
 
#10 ·
A very good point, I have fitted thinner than 3mm ones in the past.
I need to do further searching.
I was also thinking about the possibility of fitting a blanking plate (with hole) underneath the EGR valve.
 
#11 ·
Update.
I have changed direction with this idea.
I have now removed the rubber vacuum pipe from the vacuum "solenoid" (actuator?) that opens the gate that lets the exhaust gases get up the rusty orange pipe to the EGR.
The actuator is marked with a blue arrow and the rubber pipe has an orange mark on it.
I had to cut the rubber pipe (it was stuck fast on the inlet of the actuator) and then block the end of the pipe with a screw, to save losing vacuum from the vacuum pump.
I can also refit the rubber pipe when the car is being serviced and/or MOT'ed. Just in case.
So far no error codes or problems.
I think the gate in the orange rusty pipe is being held partially open even when the vacuum actuator is closed. A bit like a carburettor, if you old enough to remember them.
So the next step is to try adjusting the shaft (with the 2 nuts on it that the actuator pulls when vacuum is applied) by backing of the nuts and letting the gate close more.



Update July 18.
So my next solution was to fit a 4mm allen headed grub screw up into the
rubber pipe and then re-fit the pipe back onto the vacuum actuator.
Apart from a slight bulge in the pipe, this mod is mostly invisible.


Edited by: TonyP2020
 
#24 ·
Update.
I have changed direction with this idea.
I have now removed the rubber vacuum pipe from the vacuum "solenoid" (actuator?) that opens the gate that lets the exhaust gases get up the rusty orange pipe to the EGR.
The actuator is marked with a blue arrow and the rubber pipe has an orange mark on it.
I had to cut the rubber pipe (it was stuck fast on the inlet of the actuator) and then block the end of the pipe with a screw, to save losing vacuum from the vacuum pump.
I can also refit the rubber pipe when the car is being serviced and/or MOT'ed. Just in case.
So far no error codes or problems.
I think the gate in the orange rusty pipe is being held partially open even when the vacuum actuator is closed. A bit like a carburettor, if you old enough to remember them.
So the next step is to try adjusting the shaft (with the 2 nuts on it that the actuator pulls when vacuum is applied) by backing of the nuts and letting the gate close more.



Update July 18.
So my next solution was to fit a 4mm allen headed grub screw up into the
rubber pipe and then re-fit the pipe back onto the vacuum actuator.
Apart from a slight bulge in the pipe, this mod is mostly invisible.


Edited by: TonyP2020
I have been looking into the operation of the EGR system its cooler and its associated valves operation. If what I have found is true all the above modification has achieved is to stop the ECU diverting the exhaust gases through the cooler or straight to the EGR valve. All of the gas is still always getting to the EGR valve so it is no improvement to the amount recirculating. It is reducing the efficiency of the system making it worse for the DPF instead of better for the engine. Am I correct in this assumption?
 
#13 ·
Yes, an easy mod.
1st change all 3 bulbs to LED's or the whole light unit will get too hot.
Then add 2x 1N4004 (or similar) diodes across 3 points on the bulb holders as shown in the photo.
They are a little hard to see in the photo, but the 2 diodes connect the 3 bulbs together using diodes.
I probably need a better photo.




nigelbrooks said:
@TonyP2020

Mods: interior light now has all 3 (LED) lights on when doors ope.

Was this an easy mod?
 
#18 ·
After posting a link to this thread in another thread, I thought I would add some extra photo's.



Removing 5 bolts allows the EGR valve to move to show where the exhaust gases mix with the fresh air.



The valve that sticks open, covered in soot after 23K mikes.



The EGR valve in place.
 
#20 ·
Was there much soot on the inside of the valve? As in covered with several mm of worth of soot?

The parts in the photos do not show much soot compared with other engines I have seen with blocked EGR valves. The parts that are visible look very clean and just like mine. After taking mine apart, I think the design weakness is in the valve closing mechanism. http://www.mokkaownersclub.co.uk/forum/1-7-diesel-egr-valve_topic5783.html

I took the black plastic cover off to gain access to the return spring which I found to be sticking. (The black plastic cover in the above photos with all the ribbing). In my case the valve poppet shown in the photo was about 5 mm open until I put some silcone WD40 on the valve return spring. The valve did not run very smoothly until I worked it back and forth a few times.

I also found a bit of moisture under the plastic cover. Maybe from exhaust gas passing through the valve stem? There was no obvious corrosion. However, the moisture would not have helped either the electronics or the moving parts. Hopefully, the WD40 might help protect against the effects of moisture on both.


Edited by: Viva
 
#21 ·
Sorry for the late reply.
It was sooty, but not very much.
I didn't bother to clean the valve or take the plastic cover off.
Maybe when the weather is warmer I might clean it and then see what happens over the course of a year to the soot build up with the rubber vacuum pipe disconnected.
 
#23 ·
What was the out come of the blanking? Just having mine cleaned out on the 1.6D done 24k and it's caked. My independent suggested blanking and a ECU remap if it's a repeat problem. Don't want to do it unless I have to but not keen on periotic cleaning of the valve either.
 
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