Air blowing back from the manifold 2.8 hilux

Submitted: Monday, Mar 24, 2008 at 18:05
ThreadID: 55873 Views:10698 Replies:4 FollowUps:12
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Hi guys,

Got an 2.8 Hilux here.. NON Turbo

Just noticed air is actually blowing out from me snorkle.. not full on blowing. but when u put ur hands near the inlet where it connects.. the little gaps.. u can feel air blowing out...

Also I removed engine breather hose (on top, back of the motor) as usual the breather is blowing air out..

But the other end of the hose.. whichy connects to a barb on top of the manifold... that is blowing AIR out... at idle.. and at some point it starts to suck..but general its blowing out air.

Just doest make sense to me... How can me motor be suck air from the air intake..etc.. yet just the point before it enters the engine... there is a barb ontop of the manifold thats BLOWING AIR OUT, instead of sucking in..

ITs a wierd vacum... I dont have no turbo.. basicaly its just the engines thats sucking air in... and yet...

Is there something I dont know? pls advise.

Cheers
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Reply By: Louie the fly - Monday, Mar 24, 2008 at 19:05

Monday, Mar 24, 2008 at 19:05
This is really interesting. I have a 2.8D non turbo 4runner. I have no idea what might be the cause of what you are experiencing but I'm going to check mine to see if it does it.

I await the replys with baited breath. Good luck with it.
AnswerID: 294471

Follow Up By: Louie the fly - Monday, Mar 24, 2008 at 20:12

Monday, Mar 24, 2008 at 20:12
I just went out and checked my car. There is a hose from the rocker cover to the intake manifold. I take it this is the ERG valve. If this was blocked then the crankcase pressure not enter the manifold, it would come out of the oil filler on the rocker cover (IMO).Check by taking take the cap off.

There is no other way air can get into the intake with enough pressure or volume to come out of the snorkel while the engine is running.

I tested mine on a fast idle of about 1100 rpm. There was definite suction at the snorkel that does feel, to some extent, like air rushing out. But it is definitely suction.

Check it again - with a small piece of tissue (don't let it go) and it will confirm suction or pressure. What made you come across this again?
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FollowupID: 560368

Follow Up By: Louie the fly - Monday, Mar 24, 2008 at 20:12

Monday, Mar 24, 2008 at 20:12
I just went out and checked my car. There is a hose from the rocker cover to the intake manifold. I take it this is the ERG valve. If this was blocked then the crankcase pressure not enter the manifold, it would come out of the oil filler on the rocker cover (IMO).Check by taking take the cap off.

There is no other way air can get into the intake with enough pressure or volume to come out of the snorkel while the engine is running.

I tested mine on a fast idle of about 1100 rpm. There was definite suction at the snorkel that does feel, to some extent, like air rushing out. But it is definitely suction.

Check it again - with a small piece of tissue (don't let it go) and it will confirm suction or pressure. What made you come across this again?
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FollowupID: 560369

Reply By: Member - David P (VIC) - Monday, Mar 24, 2008 at 19:06

Monday, Mar 24, 2008 at 19:06
If its an old worn engine using oil then the exhaust gas recirculation (ERG) valve on top of the rocker box may need cleaning and that hose may need replacing. how old/kms is it?....silverback
AnswerID: 294473

Follow Up By: hilux2.8D - Monday, Mar 24, 2008 at 19:19

Monday, Mar 24, 2008 at 19:19
its a 94 model. 330Km on the clock,

It does 8.5 L to the 100 OR 11.7 km per Litre of diesel..

bear in mind its a 2 wheel drive. Dual cab. (2 wheel drive with snorkle, Yeah i know!.. things you do when you were young :0).

could u tell me more of the EGR valve.. how do it get to it ..etc..
What do U mean by replacing the hose? its not damaged...

thanks.

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FollowupID: 560357

Follow Up By: Member - David P (VIC) - Monday, Mar 24, 2008 at 19:41

Monday, Mar 24, 2008 at 19:41
The OUTside of a hose may look ok but the INside oily rotten/delaminating (inside layer collapsing) and blocking air flow. There are only so many heat/cool cycles any rubber can take before it fails? Does the hose feel softer near the engine end , good indication. Then again hoses can get hard and brittle. If it looks fairly original (14 years) its sure to be stuffed. If its been serviced properly the engine shud have plenty of life left in it. Problem is most (?) people seem to think if it starts and runs it doesn't need servicing. As a result the engine starts to consume itself, first thing you notice is an increase in oil consumption particularly on a long trip. The EGR is the breather that makes sure that the gasses that get past the piston are re consumed via the inlet side. Oil and carbon deposits can block that valve. It will be on the top of the rocker box....silverback
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FollowupID: 560360

Follow Up By: hilux2.8D - Monday, Mar 24, 2008 at 19:55

Monday, Mar 24, 2008 at 19:55
maybe I should make myself clearer, I am not experiencing any problems with the Car.

Its just that out of curiosity I unplugged the hose...

David, just a question here...

the EGR outlet... is the hose comming out from my rocket cover right?

And the other end goes into my manifold right?

I just wanna make sure we are talking abt the same hose.. the size of it is 2 cm in diameter yeah?

What I dont understand is... why when I unplug the end that is on my manifold.... out from that hose connection.. Air is blowin out... Should not It suck... Cos the engine is Sucking All the air in ?


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FollowupID: 560362

Follow Up By: Member - David P (VIC) - Monday, Mar 24, 2008 at 19:58

Monday, Mar 24, 2008 at 19:58
Before doing a 4WD course I would do a at TAFE course on servicing of a motor vehicle, a well run course will cover these things you can save yourself big money and in a 4WD potentially much more. Diagnosing an engine problem requires the same information a doctor requires of a patient...not serviced just like drinking excessively/smoking.....hope you have success...silverback
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FollowupID: 560364

Reply By: Notso - Monday, Mar 24, 2008 at 20:12

Monday, Mar 24, 2008 at 20:12
I reckon it's just the pulsating in the snorkel as the engine sucks air then stops, then sucks then stops.

AnswerID: 294483

Follow Up By: hilux2.8D - Monday, Mar 24, 2008 at 20:18

Monday, Mar 24, 2008 at 20:18
I am not too worry bout the snorkle... Thats all good like you said, just pulsating..

But the hose connection thats directly ontop of the intakre manifold... when The hose is off... ITs full on blowing air out.. :) ?
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FollowupID: 560371

Follow Up By: howesy - Monday, Mar 24, 2008 at 21:06

Monday, Mar 24, 2008 at 21:06
My 2.8 even when the motor was new pulsated through the inlet and the breather is there to relieve crank case pressure and I feel with the K's it is quite normal.
A petrol vehile might run approx. 160psi of pressure in a cylinder where as yours would be 450psi give or take (Not sure of exact 2.8 figure) so one would figure that a breather on a diesel should have 2-3 times the pressure of a petrol one. I wouldn't worry too much, if it,s doing all the right things then just enjoy driving it and have it checked by a professional if your worried.
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FollowupID: 560376

Reply By: mattwhite - Monday, Mar 24, 2008 at 22:25

Monday, Mar 24, 2008 at 22:25
The hose from the rocker cover you refer to is the PCV. (positive crankcase ventilation). EGR is exhaust gas recirculation whicn on lux's didn't get released in OZ till 5L I think. EGR is a large steel pipe from the exhaust manifold, around the back of the haed to the intake manifold. There is no PCV valve on a diesel as the intake manifold shouldn't have vacuum anyway. NORMALLY, pressure from the intake manifold would indicate leaking intake valve seats. When the piston is squashing the air in the combustion chamber and the valves leak it blows back up the intake. However, going by your fuel economy I'm not sure if you have this issue. Also, tight tappet clearances would cause this as they would hold the valves open slightly.

Good luck

Matt
AnswerID: 294512

Follow Up By: hilux2.8D - Monday, Mar 24, 2008 at 22:59

Monday, Mar 24, 2008 at 22:59
Yeah, I follow wat ye saying, its just funny to see that there is presure comming back out of the intake manifold thats allo, I'm not gonna worry bout it...

Its just that I am working on A Hydrogen project, kinda like a hydrogen hybrid.. I need to feed the hydrogen into the intake manifold.. and discovered the pressure there.

Me car is already running on 100% waste Vege oil (not Bio) .. Anyways..
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FollowupID: 560412

Follow Up By: trains - Tuesday, Mar 25, 2008 at 19:06

Tuesday, Mar 25, 2008 at 19:06
Sounds like normal air pulsation of the 2.8 diesel

Often this can be the cause of snorkle resonance particularly at 2500rpm.

so tell us more about the vegy oil setup you have.
ps, with normal running, there will be positive air flow into your motor, as a diesel dose move alot of air, and your hydrogen setup will be able to feed your motor.

Trains
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FollowupID: 560561

Follow Up By: hilux2.8D - Tuesday, Mar 25, 2008 at 20:39

Tuesday, Mar 25, 2008 at 20:39
the vege setup is straight forward, had it for 4 years now.

basically got me a Red PLastic boat fuel tank (takes up me room in me tray) and inthere I got a oil cooler laying at the bottom.. of cos had to cut a square in the fuel tank Top...

Heating the Oil..
Ran the coolant hose into the back of me tray and into the Boat tank where ti circulates thru the Aluminium Oil cooler.. Thus heating the vege oil as it sit at the bottom of the tank.

then of cos there is the fuel line.. from the Boat tank to a soleniod... where I can select to run Diesel or Vege oil...

So there is totally 2 seperate fuel line.. and as for the Return of the fuel form the Fuel pump.. I caped off the one going into the Diesel fuel tank under me ute... Then from the fuel retrun at the pump. I tee it back to to a point before the pump.. SO that means fuel Wether it be vege or diesel it will keep circulating around the fuel pump..

Presto! done.l

NOTE.. Needs to start on Diesel... to warm the oil up.. I got me a tamp guage of the oil.. Summer takes 5 mins.. Because I ran the vege fuel line.. right next to the 2 coolant lines that I taken to the back of the try.,. got it all warps into one Big Hose.. MEaning 3 hose in one.. full contact of all three hose.. Houses in a thick rubber HOSE.. (got me from the Usa) ...

TO turn off.. U need to run the last few Km's with diesel.. So u can start up in the morning again.,.. etc..


Hydrogen Gas..

Working on a cell to generate the gas.. still in early testing R&D stage....
Working out the Amps draws..etc.. many things effects it..

so yeah..
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FollowupID: 560608

Follow Up By: trains - Thursday, Mar 27, 2008 at 10:33

Thursday, Mar 27, 2008 at 10:33
Excellent, have you got any pics of the setup??

I like the idea of the trans cooler for heating the tank.
If you have a larger tank, an aircon evaporator unit, or heater unit would work well too.

Trains
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FollowupID: 560908

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