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EGR valve stuck open


Adiebt

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Engine management light illuminated , called AA , diagnosed the above , cleared the fault code and literally tapped the valve with a metal rod which caused the valve to close . Advised that this is probably just a “ glitch “ and won’t reoccur , have since covered 400 miles with no bother , what would the collective OAAL recommend ? Cheers in advance .

2013 Boxer 2.2 BTW !

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When we had our mouse problem and French pug garage was struggling to diagnose it, they stripped and cleaned egr as on Boxer it is common problem of them clogging up. They where quite surprised to see our Fiat egr was very clean.
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Adiebt - 2018-05-15 9:17 AM

 

Engine management light illuminated , called AA , diagnosed the above , cleared the fault code and literally tapped the valve with a metal rod which caused the valve to close . Advised that this is probably just a “ glitch “ and won’t reoccur , have since covered 400 miles with no bother , what would the collective OAAL recommend ? Cheers in advance .

2013 Boxer 2.2 BTW !

 

Had the same problem with my Citroen Relay 2.2

Got a stainless steel blanking plate off ebay for about £5

10 minutes to fit and works a treat

Just sailed through another MOT with emissions a small fraction of the maximum allowed.

They say on some engines it causes the emissions light to stay on (MOT fail) but mine didn't

£5 and 10 minutes work what have you got to lose.

You could make your own blanking plate but I don't recommend it because you need stainless steel.

Aluminium might melt, mild steel might rust, either way blowing metal shards into the engine.

blanking.jpg.4121b493921a768e2ef4327f4dad4213.jpg

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The EGR valve recirculates the exhaust gas back into the combustion chambers thereby reducing the combustion process temperature. This reduces the emissions, because NOx is more likely to be produced at higher temperatures, so lowering the combustion temperature reduces emissions.

 

Most vehicles that have a mod to drop the recirculation of the exhaust gas are unlikely to fail an MOT as most tests are carried out at fairly low combustion temperatures, in some cases the engine only just warm. Particularly so if your MOT retest falls during the Winter time.

 

So the blanking plates do 'work'.

However, they can also increase combustion chamber temperature, which isn't always a good thing. Especially on engines that already have a history of running lean/hot and 'holing the pistons'. Like the 2.2 Puma engine.

 

The Fiat engines have a great reputation in this respect, never ever heard of combustion temperature issues. So if it was me I would risk a blanking plate on a Fiat, but most definitely not on a Ford/Peugeot 2.2, especially on a higher power version or a heavier chassis, both of which can place an extra strain on an engine.

 

I am no expert on this subject so that should be borne in mind, but in my past life I was part of team rebuilding engines, gearboxes and doing extensive mechanical work. Including rebuilding Puma 2.2 engines.

 

 

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ColinM50 - 2018-05-15 3:17 PM

 

Adiebt - 2018-05-15 9:17 AM

 

........cleared the fault code and literally tapped the valve with a metal rod which.............

2013 Boxer 2.2 BTW !

 

Buy a metal rod? (lol) (lol) 8-)

 

He did actually show me where to tap and how ! He also showed me the sensor to disconnect that causes the engine warning light to come if the EGR played up again !

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aandncaravan - 2018-05-15 11:47 AM

 

The EGR valve recirculates the exhaust gas back into the combustion chambers thereby reducing the combustion process temperature. This reduces the emissions, because NOx is more likely to be produced at higher temperatures, so lowering the combustion temperature reduces emissions.

 

Most vehicles that have a mod to drop the recirculation of the exhaust gas are unlikely to fail an MOT as most tests are carried out at fairly low combustion temperatures, in some cases the engine only just warm. Particularly so if your MOT retest falls during the Winter time.

 

So the blanking plates do 'work'.

However, they can also increase combustion chamber temperature, which isn't always a good thing. Especially on engines that already have a history of running lean/hot and 'holing the pistons'. Like the 2.2 Puma engine.

 

The Fiat engines have a great reputation in this respect, never ever heard of combustion temperature issues. So if it was me I would risk a blanking plate on a Fiat, but most definitely not on a Ford/Peugeot 2.2, especially on a higher power version or a heavier chassis, both of which can place an extra strain on an engine.

 

I am no expert on this subject so that should be borne in mind, but in my past life I was part of team rebuilding engines, gearboxes and doing extensive mechanical work. Including rebuilding Puma 2.2 engines.

 

 

I understand what you are saying, and can see its a good point. Blocking the EGR valve is likely to increase combustion temperature and chances of holing a piston - in theory. Whether it is in practice I don't know because I don't know whether those which have holed pistons had their EGR valve blanked off?

I can only say I have done 33,000 with the EGR blanked off, engine getting hot enough to bring the fan in several times, and its been good so far...

I keep a spreadsheet of my fuel consumption which shows I did 34000 miles average 34.9 mpg. Blocked off the EGR then done 33,000 miles at 36.1mpg. But Ii don't know whether the 1.2 mpg improvement is a result of blocking the EGR valve, or the engine loosening up. There was also a period of the EGR valve not working properly before I blocked it off which would have brought the average down.

 

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Adiebt - 2018-05-15 4:46 PM

 

He also showed me the sensor to disconnect that causes the engine warning light to come if the EGR played up again !

 

Easy to stop the light coming on at all. But the MOT tester checks it comes on, then goes off when you start the engine.

PS: and if the EGR cvalve sticks open it will be very obvious because it will be throwing out clouds of black smoke and very little power below about 1500 revs - if you can get it started at all. The engine can only cope with breathing exhaust gas at higher revs and a warm engine. Thats what the valve is for, so it only lets the exhaust gas through when the engine has started, got warm, and is running at higher revs so it can cope with it.

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"Most vehicles that have a mod to drop the recirculation of the exhaust gas are unlikely to fail an MOT as most tests are carried out at fairly low combustion temperatures, in some cases the engine only just warm. Particularly so if your MOT retest falls during the Winter time."

 

Two months ago my vehicle had MOT. Oil dip stick removed and temperature probe inserted. With much engine revving oil brought up to required temperature. indicated on the testers machine and only when past a specified level was he able to carry out test. This may be change and engine was certainly not "just warm".

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sshortcircuit - 2018-05-15 5:33 PM

 

"Most vehicles that have a mod to drop the recirculation of the exhaust gas are unlikely to fail an MOT as most tests are carried out at fairly low combustion temperatures, in some cases the engine only just warm. Particularly so if your MOT retest falls during the Winter time."

 

Two months ago my vehicle had MOT. Oil dip stick removed and temperature probe inserted. With much engine revving oil brought up to required temperature. indicated on the testers machine and only when past a specified level was he able to carry out test. This may be change and engine was certainly not "just warm".

 

Yes, come to think of it I had just driven 3 miles to the centre on a warm day and he took it straight in and left it running about 15 minutes before doing the exhaust test so mine must have been about normal working temperature. The MOT certificate shows the smoke emission - with the EGR blocked off - still only about 15% of the maximum allowed.

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There is a big difference in combustion chamber temperatures that melt pistons in an engine flat out up a steep, long hill in third gear and one left idling unloaded for 15 minutes.

 

The purpose of the EGR is solely to reduce NOx emmisions, which are normally only produced at high combustion chamber temperatures, not Oil or Water that is up to temperature, which is obviously very different.

 

 

 

You write -

"- with the EGR blocked off - still only about 15% of the maximum allowed".

 

Isn't that proof that combustion chamber temperatures were only warm despite the Oil temperature being 'hot'?

That the machine wasn't recording high NOx figures when the EGR function has been deactivated suggests that NOx production was low because the combustion process was 'cool'.

 

 

I would also suggest that an improvement in fuel consumption from 34 to 36 MPG after deactivating the EGR valve may also indicate weakened fuel mixture, which again tends to result in raised combustion temperatures.

 

 

But I did say I wasn't an expert and obviously those who wish to take a risk will.

 

 

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Cleaning them usually yields good result on young EGR's.

Carb Cleaner is very good at getting them clean.

 

Older units tend to be react less well to cleaning as there is sometimes wear along with the gunge.

 

Unless yours has done a lot of miles I would try cleaning as a first measure.

 

 

 

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aandncaravan - 2018-05-15 6:54 PM

 

There is a big difference in combustion chamber temperatures that melt pistons in an engine flat out up a steep, long hill in third gear and one left idling unloaded for 15 minutes.

 

The purpose of the EGR is solely to reduce NOx emmisions, which are normally only produced at high combustion chamber temperatures, not Oil or Water that is up to temperature, which is obviously very different.

 

 

 

You write -

"- with the EGR blocked off - still only about 15% of the maximum allowed".

 

Isn't that proof that combustion chamber temperatures were only warm despite the Oil temperature being 'hot'?

That the machine wasn't recording high NOx figures when the EGR function has been deactivated suggests that NOx production was low because the combustion process was 'cool'.

 

 

I would also suggest that an improvement in fuel consumption from 34 to 36 MPG after deactivating the EGR valve may also indicate weakened fuel mixture, which again tends to result in raised combustion temperatures.

 

 

But I did say I wasn't an expert and obviously those who wish to take a risk will.

 

 

Good point so I'll try not to flog it too hard up the long hills.

With 120 horses pulling 3.4 tonnes there seems power to spare.

The first lorry I drove had 100 horses for 16 tonnes

The next had 180 horses for 32 tonnes.

(plus manual steering, shook you to bits and noise to make your ears hurt)

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aandncaravan - 2018-05-15 8:26 PM

 

Cleaning them usually yields good result on young EGR's.

Carb Cleaner is very good at getting them clean.

 

Older units tend to be react less well to cleaning as there is sometimes wear along with the gunge.

 

Unless yours has done a lot of miles I would try cleaning as a first measure.

 

 

 

2013 van. , done 30050 miles , is that a lot ? We’ve had the van from new , serviced on time etc .

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Adiebt - 2018-05-15 9:39 PM

2013 van. , done 30050 miles , is that a lot ? We’ve had the van from new , serviced on time etc .

EGR cvalves can block at lower mileages than that.

Its more about the way you have driven it than the miles you have done.

It only opens at higher revs with a warm engine, so if you have been using low power and a cold engine much like most motorhomers, its much more likely to clog up and stick than with whitevanman regularly flooring the throttle to open it up.

My evidence of a 1.2mpg improvement since blocking off the EGR is inconclusive, since it may be due to the engine loosening up in use or the EGR not working properly. And as aandcaravan points out, blocking off the EGR on the 2.2 engine may increase the risk of pistons melting at high power output. Hasn't happened to me but it might. I have heard blocking off the EGR on the 2.3 brings on the emissions light (MOT fail) unless you use a plate with a hole in (a sort of half measure) In which case its important to use a stainless steel plate for heat resistance. Like a hot water tap gets hotter when the water is running than when its closed. You would probably get away with an aluminium plate (which being softer makes a better seal) if the you can use a plate without a hole without bringing on the emissions light.

So I wouldn't suggest blocking off the EGR if its working OK. But its a relatively quick easy fix if you are broken down with a blocked EGR. Provided you have a spare blanking plate in your toolkit and know where to fit it.

 

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"Good point so I'll try not to flog it too hard up the long hills.

With 120 horses pulling 3.4 tonnes there seems power to spare.

The first lorry I drove had 100 horses for 16 tonnes

The next had 180 horses for 32 tonnes.

(plus manual steering, shook you to bits and noise to make your ears hurt)"

 

I'm guessing the 180 horses will have been Gardner horses, which are much stronger than Fiat horses. As I'm sure you know, when it comes to pulling power torque means far more than horsepower.

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"I'm guessing the 180 horses will have been Gardner horses, which are much stronger than Fiat horses. As I'm sure you know, when it comes to pulling power torque means far more than horsepower".

 

 

Aandy, Maybe it was even the legendary Gardner 6LX, 10.5 litre, 180 bhp engine from 1964? It's max power was delivered at just 1,800rpm so the torque must have been astonishing for it to haul a big lorry or Bus.

That it did so with immense reliability made the engine an Icon.

 

As you say very strong big Horses.

 

 

 

 

 

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Spoke to my mechanic at my trusted garage and he said “ glitch “ and the 300 mile runout post AA visit will have done it the world of good , so alls good for now ! Thanks so much for all your help and input , if it recurs then I think a clean will be the way forward , thanks again!
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aandncaravan - 2018-05-16 8:54 AM

 

"I'm guessing the 180 horses will have been Gardner horses, which are much stronger than Fiat horses. As I'm sure you know, when it comes to pulling power torque means far more than horsepower".

 

 

Aandy, Maybe it was even the legendary Gardner 6LX, 10.5 litre, 180 bhp engine from 1964? It's max power was delivered at just 1,800rpm so the torque must have been astonishing for it to haul a big lorry or Bus.

That it did so with immense reliability made the engine an Icon.

 

As you say very strong big Horses.

 

 

 

 

My ERF was a Perkins diesel, Gardners were better.

But still noisy smelly and sluggish horses with vibration to shake your guts out.

ERF / Foden is the only British Engineering Company I'm glad to see the back of.

Bit harsh, but they gave such little thought to drivers they can't expect much in return.

One of my happiest days at work was when I got my first Volvo.

Like to see the ERF/Foden at the steam fairs though

If only to remind me I don't have to driv that crap anymore :-D

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Adiebt - 2018-05-16 6:16 PM

 

Spoke to my mechanic at my trusted garage and he said “ glitch “ and the 300 mile runout post AA visit will have done it the world of good , so alls good for now ! Thanks so much for all your help and input , if it recurs then I think a clean will be the way forward , thanks again!

 

Well yes, but if the EGR valve sticks open so you can't get it started, slipping a blanking plate in will get you going much quicker and easier than taking the EGR valve off to clean and free it.

Good Luck anyway :-D

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My advice would be to fit a new EGR valve. Once the EGR valve starts to have problems on the 2.2 Puma engine it will get worse and can reach the stage where the vehicle is almost impossible to drive. The internal mechanics just wear out and the usual failure mode is that it fails to close. Under these conditions, even if the vehicle runs, it will be emitting black smoke. Cleaning is usually only a temporary measure.

 

A partially faulty valve will cause an over rich fuel situation increasing consumption. Replacing or blocking will improve the fuel consumption. There is very little improvement in fuel consumption between a correctly working valve and a blanked of valve.

 

A blanking plate will work on a Euro4 vehicle without setting fault lights, Euro 5 may have a problem. Of course if going down this path there are the legal and moral issues.

 

The usual argument against EGR blanking is than the engine will run hotter and the pistons will melt or the turbo will fail. In normal operation the EGR only feeds back the inert exhaust gas into the combustion chamber when the engine in under light load and this does lower the EGT, exhaust gas temperature, and thus nitrogen oxides emissions, ( NOx for the various oxides of nitrogen). Under high power conditions the EGR is closed and has no effect on exhaust temperature. Now I am no engine designer but logic says that the EGT will be much higher at high loads, where there is no EGR action, and the EGT will be much less at low loads, where the EGR action lowers it even more. Since the engine is designed to operate at high loads I suggest we can discount the lack of EGR causing serious failure. In some countries where there are lower emission standards EGR operation is omitted by the manufacturer.

 

You can feel the EGR action on the Puma Engine at just under 2000 rpm on a light load, the engine has a slight hesitation.

 

As fas as I know the MOT does not test NOx emission, only smoke levels and the test is carried out at normal operating temperatures.

 

The usual cause for piston failure is local overheating to a faulty fueling, most common in the Ford Transit, Peugeot/Citroen have a different injection system and its much less of a problem although not unknown.

 

Diesel engines run very lean compared to petrol, between 20 to 150 air to fuel ratio, there is always excess oxygen thus reducing smoke. The downside is that the high air temperature at light load, where the AF ratio is the highest, produce NOx. The EGR system replaces some (perhaps quite a lot) of the intake air with inert exhaust gas, reducing the AF ratio, a combination of less air to convert and a lower air temperature reduces the amount of NOx. At high load where the AF ratio is much lower there is no need for EGR action as there is much less 'spare' hot air to convert to NOx.

 

Mike

 

 

 

 

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mikefitz - 2018-05-16 10:51 PM

 

Once the EGR valve starts to have problems on the 2.2 Puma engine it will get worse and can reach the stage where the vehicle is almost impossible to drive. The internal mechanics just wear out

Very Interesting post, Thanks :-D

Not sure the EGR problem is wear though.

I thought it was the opposite - lack of use clogging it up.

Whitevanmen and Couriers doing hundreds of thousands of miles have never heard of the EGR valve because their style of driving keeps it working and freed up.

Wheras old duffers in motorhomes - stop, start, cold engine low revs ... the EGR gets clogged from lack of use and sticks. Until they finally go over about 1500 revs, the EGR valve finally opens and sticks, and they think its their driving too fast that has wrecked it (lol)

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