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Old Jun 19th, 2011, 20:14   #1
Biotoxic
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Cool Information regarding EGR related problems and solutions.

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Information about EGR

So then, you bought your car, a Volvo S40 1.9 turbo Diesel(or diesel in general) with Renault engine
(or any other diesel car), or you already own this car. Once in a while you will need
to check and clean EGR as a preventative maintenance, so that your car keeps runing for a years to come.
(read the text bellow to get some knowledge about how EGR valve works)

After reading this thread you should be able to diagnose and fix EGR related problems.

Over the time and possibly due to some mechanical problems you might notice that car doesn't
perform like it did some time ago. Your mpg are lower or higher than normal, it may not accelerate
the same way it did a while ago, sluggishness, hesitation at traffic lights, can't rev engine past 4000rpms
or car has no power bellow 3000rpms. There might be some problems with rough idling and failing to
past the MOT test due to emissions....
The answer and possible solution/prevention to this problem is quite easy.
Most of the times it's partly or completely blocked EGR that could be cause of the problem. Over time soot
and oil accumulates in and around the inner part of EGR. If you don't keep your eye on this, you might even
get Engine warning light in dashboard. My suggestion is that you check this EGR valve once every time you
change your engine oil. Or if you are driving a lot then clean or inspect it every 10000-20000 miles(aprox)

Amongst other possible things that can cause all mentioned above, cause of blocked EGR could be *blown turbo,
turbo seal failure, crack in turbo itself, blow by(oil catch tank), air leaks around hoses, damaged intercooler...
If one of these things mentioned above fails, engine oil will find it's way to the air intake manifold.
If there is a damage to turbo/worn turbo seals, most likely oil will end up in Intercooler, then oil is forced up
the intercooler and then ''travels'' to EGR and air intake manifold, from there its sticks to every
metalic/aluminium surfaces that it touches. I even had soot inside cylinder itself, it was on cylinder heads and
on the pistons. Even if there is no damage to any part mentioned above, oil/soot deposits still can build up.
Most of the times the cause of that oil and soot in and around EGR AND INLET MANIFOLD is quite unexpected.
It's economical driving.. yes it is!
It might town driving, or it might be A or B roads. This particular engine needs to be looked after
more than other engines.
To keep problems from actualy happening(blocked EGR) I am giving you a lesson in driving.
In a town or 30 mph zone drive in 3rd gear not 4th. If you are going faster than 40 mph, change to 4th gear.
If you are doing faster than 55 mph you can change into 5th gear.
This is because if you drive slower with higher gear, temperature in a cylinder decreases,
this doesn't sufficiently burn diesel. Diesel mist combined with soot enters EGR valve and then goes back to
intake manifold, it sticks on every possible metallic surface along the way. Over time it accumulates and it's blocking
EGR valve from working properly. Valve might get stuck in closed position, half open or open position.
Egr valve recirculates some of the exhaust gases back into intake manifold thus lowering emissions.
Valve opens when engine is started from cold(to speed up the heating of the inlet manifold, so your
engine heats up more faster and burns diesel more efficiently) it stays half open or open when you reach
cruising speed, but valve closes on acceleration, so if your car struggles to pick up speed on full throttle or it is
hesitating at low rpms, then I am 90% sure that EGR valve is stuck ether open or half open letting pressurised air
out trough shortest possible way, wich is that opened(stucked in open position) EGR valve. The turbo compressor
blades acts like hoover, it's sucking air out from intake manifold, suffocating engine from air and thats why engine
looses power in low rpms and it feels like you are towing a tractor or peace of large timber.
P.S. about that hoover(vacuum), example from childhood. I tried this, I know how it feels. Take an end of
the hoover pipe, put it in your mouth but close your lips around the hose, switch on the hoover and let the air in trough your nose,
then when the hoover is working and air is sucked away from your mouth and nostrils try to breathe....
it will be hard to do that. Once you do that, you will know how engine feels...

NOTE: I have heard of some cases when car owners are blanking EGR valve. I won't recommend it. Although you might
get some acceleration gain, you will end up paying for the consequences. If you have DPF, it will get blocked
faster. Engine management light could come on and there could be other warning lights lit on the dashboard.


So then, you actually read trough the whole text(probably), now you should know what is causing youre engine to
loose power in low rpms....

NOTE 2: This is roughly the same for all diesel engines fited with EGR valves out there, peugot, citroen, bmw, MB, etc...

Few pictures of blocked EGR valves from different diesel engines.
from land rover
6 litre ford
BMW E46
for volvo D5 http://www.volvoforums.org.uk/showth...&highlight=egr


this is what I talked about in my text above, blocked/clogged EGR valve.



Coming up next: Guide how to remove EGR, how to clean it, and what to do after you have put all the things back
together.
Don't go anywhere, I will be back after the brake!
+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


So then:
Tools you will need!

Flat head screwdriver.
Hammer or rubber hammer.
A peace of stick(idealy with 90 degree edges)

A carb cleaner, electric contact cleaner or something that loosens up a soot, but don't Use WD40, after that liquid
evaporates, that area will be sticky. It will actualy help build up soot faster.
Some gloves or kitchen towels(to keep your hands clean).
Size 7, 10 and 12 spanner and/or socket.
Size 40 torq

Time: If you are doing this for the first time, it will take about 2-6 hours to remove parts, clean them, and put
them back together, hardest part should be inner EGR removal(there is some EGR valves that are welded together,
originaly it comes in two peaces inner and outer part). If you have removed that, then you have done half of the job.

If you are doing this for the second time on the same car and if you know what to do, then it should take
no more than 1 hour.


Remove engine cover by undoing 3 torq type bolts


This picture shows you what you will need to remove in order to get to the EGR valve


Unclip this by using screwdriver

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


disconnect cable from pressure sensor and uplug cable from holder


use screw driver or size 7 socket to release the clamps from
butterfly valve(air shut off valve)
and
Intercooler

then
remove the whole pipe
+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.



To get easier access to EGR valve you have to remove butterfly valve. Do this by undoing 3 bolts
size 12 or 14

(ignore number 3)
then move it away from intake manifold and just pull off the vacuum hose


inspect and clean it as necessary.

After you remove butterfly valve, you should be able to to see what is going on inside air intake manifold
this is good

but
this is bad
if it is full of soot then you have reached the hardest part, if you can see uneven metallic surface inside manifold(picture this is good), then inner EGR valve probably will come out with little or no resistance.


Remove outer part of EGR valve(EGR should be in two peaces)


Disconnect the cable


then unscrew 3 bolts that holds outer EGR part.



If that manifold is full with soot then you will need a hammer or rubber hammer, with peace of stick and some
carb cleaner or similar substance to loosen up the soot( it acts like a rubber between two tight metal parts,
impossible to move it with bare hands)

Remove inner part of EGR valve by using some anti rust spray, Carb cleaner (or something like that)
To remove it, use a peace of wooden stick and rubber hammer. Try to hit it with a little force, bit by bit clockwise and spray carb cleaner and then few degrees anticlockwise and spray carb cleaner again, do this until it feels loose.
Do that until you are able to use both your hands and then just one hand.



If you EGR is ok, then it should come out fairly easy. See video
+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


This is how clean inner EGR part should look like(at least it should look similar)



Once you remove inner part, inspect and clean it.
I used pieces of old bed linen, after that I used old toothbrush. After you have cleaned inner EGR make sure
that it seals perfectly, you shouldn't be able to see large gaps, when you are pointing it against the lamp or
other light source.

When you have finished cleaning both EGR valves, clean EGR valve socket, make sure you clean all burned in
oil/soot/gunk, then clean two gaps between EGR socket and air inlet manifold.

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


Then when you are statisfied with results, clean air intake manifold as far as you can reach, but try not to
push any large peaces of soot/oil deeper inside manifold.
Double clean everything inside air intake manifold and EGR valve socket just in case if there is something left.

Insert inner part of the EGR valve back in place, If there was an oil leak before you removed EGR then you can
make your own gasket(link) it should stop oil leaking from EGR AND seal any air leaks(if there is any).

Next steps are just putting things back together in reverse order.
After you have finished and tightened all the bolts that you unscrewed, double check if you have connected all
the electrical connections. Then double check it in reverse order!
Do not put that plastic engine cover on just yet.
After all that, start the engine and let it warm up untill it reaches operating temperature. Check for any leaks,
then go for a test drive some where near your place, just in case if there is any problems you can sort it
out near your house. Even better, bring all the tools with you. it will save you some time
If every thing is ok so far, put in the second gear and floor it, if it feells slower than it used to be, then
there is an air leak from air hose coming from intercooler-going to butterfly valve or connection between
buterfly valve and air intake manifold, or around egr valve. If there is air leak, you should see some traces.
Just tighten the clip/s to seal hose properly.
Note: Sometimes, after cleaning EGR valve/intake manifold you could still get sluggishness/hasitation/slow
acceleration. Following text should help you to ged rid of that.


After you have successfuly test driven your car find a motorway.

Fallowing text will help you to clean air intake manifold, piston and cylinder heads as well as DPF(Diesel
Particulate Filter)

Important: Before you do this, you should check oil level, coolant level, tyres, brakes.

Read these threads to get the bigger picture. Text bellow might be confusing.

starting from the post No 7
Italian tune up



Best thing when to do this is on Sundays, or any other days when there is almost no traffic on the roads.
Accelerate to the 4th gear. You should be doing about 50MPH at 2500 rpms in 4th gear.
Accelerate to ~4000 rpms in 4th gear.
Note: You will be over legal speed limit by a bit. (In UK it's 70 mph on motorways)
Drive at ~4000 rpms for about 2 miles, then change to 5th gear and continue to drive normaly.
When you return home do not stop the engine. Let the car idle for about 2-3 minutes.
This will help engine to cool down normaly. Parts like Air intake manifold, pistons, cylinder head, exhaust
manifold, turbo, DPF(if you have one) will be very very hot. If you switch of the engine right after you
park your car oil could burn to the hot metalic parts of the turbo/turbo pipes. Over time those pipes
could get block, or if that burnt oil sticks to the turbo bearings, it will make turbo shaft woblle a lot,
thus damaging turbo seals/bearings over time.

Letting car idle for 2-3 minutes helps avoid this problem. This is especialy important after you get a new
turbocharger...

After that test drive(A.K.A Italian tune up) leave your car to cool down.
Next day you should notice that your car performs a bit better. This is due to high temperature that burned
off all the soot and other junk that was inside inlet manifold, exhoust manifold, DPF and exhoust pipe.
Check for any oil leaks, check oil and water level as well.
To keep your diesel car runing for a long time, don't forget to check EGR valve(soot or oil that accumulates
there) once every time you change your engine oil. Or if you are driving a lot then clean or inspect it
every 10000-20000 miles(aprox)


This is all that I know of diesel car EGR valves.
Information that I posted here I found out
from volvoforums members, diesel mechanic, interweb( ) and other forums related to: diesel egines,
turbo chargers, street racers, youtube and then I just put all pieces together.




Tags/key words.(just for a search filter)

EGR, EGR valve, Exhoust Gas Recirculation, Diesel, Diesel Engine, Engine, Soot, Blow by, Intercooler, Inter
cooler, Turbo, Turbo charger, Turbo Shaft, shaft, Blades, Compressor, pressurized air, Volvo, S40, V40,
Sluggish, slow, bad accelleration, slow acceleration, hesitating, hesitation, oil, oil catch tank, no power,
low power, Inlet manifold, Air inlet manifold,
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