The Mitsubishi Pajero Owners Club®

The Lewis Mob · Posted: Tue Dec 16, 2003 17:03 Post subject:

Seems to be a common problem this Crying or Very sad

When i blocked off my EGR at the weekend, i noticed a small trace of dirty oil around where I had fitted the plate after a test run - bu##er I thought, should have used some jointing compound when I put the plate on. Trouble is, cant do anything until this weekend to rectify it.

Since then, the thought has been mulling in my head that surely there should not be this amount of oil present in the first place, and does this mean trouble?

any ideas why this happens - apart from the dreaded valve guides etc, would be very well recieved. Before fitting the plate, there was never any oil present around the EGR, nor does my Paj smoke, fart or grumble when started first thing.

looking forward to hearing more views on this one.

Cheers

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ade · ***** Joined: 27 Apr 2003 Posts: 514 Location: OuTaSpAcE

Hi Trig,
Does the oil level go down on the dipstick much between services?

I`m sure I read In the forums here somewhere that a blocked pipe causes your oily egr. Was something to do with the turbo not breathing properly and sucking the oil out the motor.
can`t for the life of me find it though.....

btw only suspect stem seals if you get a BIG plume of smoke when starting from cold (left overnight) or a couple of days.

if your oil control rings had gone, so would yer engine, usually fatal on diesels. revs to oblivion until something breaks!

hmmm back to searching ...........ATB

Trig · ****** Joined: 24 Nov 2002 Posts: 1379 Location: N. Cyprus

The Lewis Mob · Posted: Tue Dec 16, 2003 18:40 Post subject:

trig,

to be honest, there is no real difference with mine with the EGR blocked, apart from a slightly more sustained accelaration in the middle gears / revs.

I had the EGR blocked off with a golf tee for several weeks awaiting the plate via the club, and no obvious oil marks were noted around the EGR until i fitted the plate. Now there are "weeps" of oil around the plate - nothing more, but this indicates the presence of a significant amount of oil within the EGR.

My concern is, was this oil there anyway, or has something changed by fitting the EGR plate - I cant think that it could have , but you never know, and does this indicate anything more sinister.

Again, either with it blocked or not, we get next to no smoke on start up, and when running at opperating temp, nothing at all.

Curious to know what is causing it is all - like to understand how / why things work etc.

cheers

Paul

Trig · ****** Joined: 24 Nov 2002 Posts: 1379 Location: N. Cyprus

TheLewisMob, I think that oil was THERE before... with the valve being blocked off, more of the oil traces collect and show more than before!! You can stop it sjhowing by applying some silicon seal on the plate before tightening the bolts Idea

PeteMillis · ***** Joined: 08 Jul 2003 Posts: 845 Location: Sussex, UK

Now here's a thought......is it definitely oil or could it be wet diesel soot/crud? It seems that it would be more likely for exhaust gases to leak though a slightly imperfect seal than it would for oil and I can't for the life of me think why oil would be there anyway. If there was oil getting into the cylinders then it would leave them by the easiest route which is via the exhaust - it would NOT be forced out of the cylinders via the inlet manifold I reckon the best bet is to whack some high temp silicone sealant on each side of the blanking plate before putting it in then no exhaust gases can get through.
Another thought is that one of the things that most improves performance is a better power to weight ratio. Why not reduce the weight by dumping the EGR valve in the bin, blocking the vacuum pipe and blanking off the hole left in the inlet manifold?
Bear in mind all of you that Exhaust Gas Recirc reduces emissions of nasty photochemical fog causing compounds.....
Pete

The Lewis Mob · Posted: Tue Dec 16, 2003 19:37 Post subject:

Pete,

you could be right about the diesel oil, crud, soot thing - just assumed it was oil. Already planning to put some instant gasket carefully around the mating surfaces on the weekend to see if this solves it?

trouble is, now I have seen the "crud", makes me want to know what, why, where, how, etc - am I sad or what?

Cheers

Paul.

Mystery Machine · *** Joined: 04 Jul 2003 Posts: 179 Location: Bristol

Hi Guys,

Been watching this post with some interest.....would like to find out how my 'oily' EGR got so messy, and you've all raised some interesting points!! 8)

I'm having a service, all new belts and pulleys done on Fri (along with tappet adjustment and new upper gaskets) I'll ask the chap about the 'oil' on the EGR and see what he says (and of course I'll let you know what he says!)

The only thing I'm concerned about is the amount of smoke mine throws out on start-up!! Embarassed

It's no different since fitting the EGR plate, but always assumed it's a 'characteristic' of the engine!! It runs REALLY well, and all seems OK when it's 'cleared it's lungs', it's just after reading your comments, I hope it's nothing more sinister!! Confused

By the way, the blanking plate has made little difference to power, but it drives a lot more smoothly and progression between gears is better, and the MPG is very slightly improved, but when you're getting 24MPG instead of 23, this isn't going to save me too much money!!! Rolling Eyes

Regards,

Bruce.

charlieisleofwight · Posted: Tue Dec 16, 2003 21:52 Post subject: ???egr???

Can someone tell me what the egr valves purpose is and why is everbody blanking them off ????
Regards charlie

PeteMillis · ***** Joined: 08 Jul 2003 Posts: 845 Location: Sussex, UK

Charlie, the EGR (Exhaust Gas Recirculation) valve is an emissions control device that reduces emission of nitrogen compounds in the exhaust. These compounds are known to be the main cause of photochemical smog in cities (this is the modern day smog that irritates lungs and other mucous membranes and is possibly carcinogenic). However, some people believe that recirculating exhaust gases increases soot in the diesel and reduces power so blank them off. It may be that blanking off a dirty EGR could reduce soot as soot will not get blown out of it every time the foot is put down and the EGR allows exhaust to recirculate into the inlet manifold. My problem is that I am a scientist and as far as I have seen there is no conclusive evidence that blanking it off improves performance and/or fuel consumption. Many people say it does but nobody has committed a vehicle to a dyno to prove it!
I'm considering blanking mine off to experiment but want to do it step by step and when funds allow me to get the motor on a dyno. The only way to tell what's going on is to 1. stick the motor on a dyno to get a baseline reading and measure emissions, 2. clean the EGR internally to make sure it's working as it should be 3. stick the motor on a dyno again and remeasure emissions, 4. blank off the EGR 5. repeat step 3.
Then probably find there's no significant difference in anything except an increase in nitrogen compounds!
I'd be interested to see any dyno runs that anyone's done so far. I just feel that it's a bit futile trying to improve the performance of a lump of diesel engine that's designed to chug along. A very small change in driving style is going to a far bigger effect.
Pete

Trig · ****** Joined: 24 Nov 2002 Posts: 1379 Location: N. Cyprus

Mystery Machine · *** Joined: 04 Jul 2003 Posts: 179 Location: Bristol

colin houlding · ** Joined: 13 Apr 2003 Posts: 57 Location: bristol

Why do everyone worry about a little oil, if the levels not going down unduly and its not smoking when hot think of the oil as a rust stopper, as it will never rust around that area. Mine has oil on it and i just wipe it off when ever i check the oil level, I never think about bangs or things like that because i like to keep my blood pressure down and my bank balance up for the more important things in life. I have blocked mine off and it do make a slight difference to performance and fuel consumption 30mpg at 65 mph
Colin H Very Happy

Metnav1 · *** Joined: 24 Jun 2003 Posts: 225 Location: Suffolk

EGR valve in a deisel does the same thing as in a petrol car.

They get dirty with exhaust, and malfunction.

Normally they allow exhaust back into the engine to help warm up the mixture, and reburn over rich exhaust.

Deisel is messy stuff to start with, and when the engine is cold even worse.

This is when the EGR (Exhaust Gas Recirculation) allows the exhaust through.

This will cause oily half burnt deisel through, and cause oily deposits (deisel is oil)

Also because deisel is messy the valve will get clogged and malfuntion rapidly (compared to a petrol car)

The normal malfunction is to not seal properly.

This would cause incorrect running during normal operation. Less power, poor MPG, and poor combustion (Black smoke)

So if the EGR is working, there is no real gain from blanking.

But deisel EGRs malfuction more often than not, so blanking them is common practice.

As far as emmissions go; you will be better off with a blanked EGR than a malfunctioning one.

As my favourite mechanic said, "They're more trouble than they're worth"

PeteMillis · ***** Joined: 08 Jul 2003 Posts: 845 Location: Sussex, UK