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1.5dci breathe oil

12K views 15 replies 6 participants last post by  vonrad 
#1 ·
Hi everyone.

I hope that someone can help me with the problem I have on my Nissan Micra 1.5 Dci (Renault 1.5dci K9K engine).

The engine has overheated and ran away with me due to an air lock after replacing the thermostat housing and not switching the heater box on while bleeding the cooling system. Now the motor was smoking and I was told that I should look into replacing the turbo. So I bought a Borg Warner Core and replaced the turbo. But the motor still wanted to run away with me after the replacing of the turbo.

We stripped the motor and found that Number 1 Piston was melted away... Note that the motor was still starting first time by the touch of the key.
I took the motor in for machining and replaced the pistons with n good second hand set. The rings was replaced (KS rings) and also the head was pressure test and came back ok. We assembled the motor and installed it into the car just to find that the car don't want to start first time... it takes very very long to start. When it does start it idles good. But after a minute or so the Motor starts to breathe very badly( out of the breather on the tappet cover and the dipstick). I was told to strip the motor again and the engineers said that it could be due to the sleeves being a little oval. So they resleeved the block and we again installed new KS rings.

After assembling the Motor again and installing it into my kar I found that the engine was still taking very very long to start (While cranking). After it starts it once again starts breathing smoke and oil out of the breather pipe and the dipstick. I got the Engineers to come to my place to show to them what the motor is doing. Guy said its like there is no rings on the pistons the way this motor breathes...

Then I was told to take the motor apart again. They checked the rings and sleeves again after all was taken apart and could not find anything wrong. So I was told that lets again try different set of rings... I was at this stage feeling like we are closing our eyes and shooting in the dark trying to get to the problem.
I have decided to go for a second opinion at a different engineering shop and the person came and did all the measurements of the Block, Pistons, Rings, and also Crank and he could not find anything out of spec and he said that the problem must be somewhere else.
They Engineering place said that I must check the EGR. Can the EGR cause sump compression? Mine is not being used in the first place. the car don't have a plug for the EGR in the loom (South Africa Spec).
Can someone please guide me in the correct direction cause as you can see this car is getting the best of me and has cost me a arm and a leg already.
I really need this car and it has been standing for 8 months already due to the Sump compression issue.

Please assist

Thank you in advance!

Hans Swart.
 
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#2 ·
Presume the head gasket was properly inspected during rebuild (and replaced each time). Has any work been done to the cylinder head? It is possible it may have deformed or cracked during overheating?
 
#3 ·
If the intercooler wasn't cleaned out, The oil remaining in there would IMHO cause this.
Also Has the thermostat housing been removed, checked & resealed? There are OIL & WATER galleries side by side AND the housing is Plastic.
 
#4 ·
We did check the head gasket after stripping it again and there was no sign of any possibility of blowing through. The head has been pressure tested and after the motor overheated. I also think they did replaced the valve stem seals. engineers told me that the head is good.

Thank you for your reply!
 
#6 ·
Dont know if you fancy this idea, and it is up to you if you do it.
That is if you are 100% you have no issues with your turbo...
Take the heater/glow plugs out, and pour a cap of automatic transmission fluid down each bore, .... heater glow plugs back in, and start the car,,,see if that will allow the rings to " BITE " makes them reseat quicker....
 
#7 ·
Sounds to me as if you have a malfunctioning PCV valve.

The positive crankcase ventilation or PCV valve is an inexpensive and often overlooked component. It is also one possible cause of expensive oil leaks and sludge buildup in an engine.

All automotive engines are lubricated with oil and when oil is churned by moving parts, pressure is produced. Piston rings and valve guides also leak slightly producing pressure in the crankcase. Many years ago, they simply vented the pressure into the atmosphere with a road-draft tube and breather cap. Today we use a positive crankcase ventilation or PCV system to handle this and other task.

The PCV system is relatively simple. An inlet hose connects to a filtered air source. This is used to supply clean air that is drawn through the engine. Most of the time this air is supplied through the engine air filter. On a few designs there is a separate inlet filter that cleans the incoming air for the PCV system only. This filtered air flows through the engine, picking up fumes and vapors. The air exits through another hose, connected to manifold vacuum. The flow of air draws fumes from the crankcase and burns them harmlessly in the engine. This also creates a slight vacuum, relieving any pressure that may build. Negative pressure helps to prevent oil leaks and oil consumption by the engine. The PCV valve also helps regulate the amount of air flow, which helps prevent oil being drawn out of the engine.
 
#8 ·
Good day everyone.

I am still struggling with this motor with sump compression. I have even tried a different manufacturer for the rings. When I took the oil return pipe from the turbo out of the block the motor still had sump compression. So I would then believe that the turbo is not the culprit causing the sump compression. My mind is telling me that there is a problem somewhere at the cylinders because the car takes long to start and also when it is idling there is greyish smoke that comes out of the exhaust.. Unburned Diesel. you can smell the diesel in the smoke. Its looks the same as when you start a diesel car up for the first time when its cold with a faulty glow plug... in this case the motor idles very nicely but the smoke at the back you can smell its diesel.

Just to give a better explanation of what I have found as well...
I have removed the breather pipe completely with PCV from the tappet cover. And also removed the oil return pipe from the turbo to the sump. After this I checked and found excessive pressure (Greyish in colour) at the sump hole for the turbo return pipe, at the dipstick hole and also at the breather pipe section on the tappet cover. With all three holes open there is sump compression. Tell me if I am wrong but this to me all points to blow-by at the rings. But the engineers tell me that it cant be because everything is within spec.

Any help would be greatly appreciated...

Thanks,
Hans.
 
#12 ·
Hello again,
I see you have tried the PCV valve with no success. I read your first thread again where you said you had the cylinder(s) machines and replaced the pistons with "a good second hand set". I suppose that you machined all the cylinders? In that case you should have fitted oversized pistons as otherwise the clearances between the piston(s) and cylinder(s) are excessive. Cylinder leakage for newly overhauled engines is usually in the range 10-12% and for a good run in engine 7-8%. My guess by reading your first thread is that you did not have any problem with excessive crankcase pressure prior to the overheating of the engine. By reading your first thread I am almost sure (I said "almost") that you are experiencing excessive clearances between cylinder and piston.
 
#10 ·
The amount of oil that the motor is throwing out is scary... That's why I have not even tried to drive the car. It throws oil out of each hole.

By letting it idle for 30 min the motor breathed 1 L of oil out at the breather pipe. I thought about towing something with the car so that the motor can work hard and help the rings to bed but I am concerned that the motor under boost will not have any oil left in the sump after just driving around the block...:crying2:
 
#11 ·
If my memory serves me right the engineers said that my pistons is between hundreds and two hundreds of a millimetre out of spec. Can this cause the huge sump compression that I am currently having? Al rings are correctly installed on the pistons as well...

Hope that the knowledgeable guys out there can help me.. I am sitting with my hands in my hair for the last year already with this problem...


Thank you,
Hans.
 
#14 ·
Hi,
Its been a view years since my last update,

I replaced my tappet cover with a good second hand one which still had the breather splash try in place. This managed to seperate the oil from the breathing and i managed to drive the car again. its definitely not perfect and i am still under the impression that i am sitting with sump compression (blowby) because some times i can hear a ping coming from the engine while accelerating. but i have done about 40 000km and its still running (not the way it should).

One engineering shop tells me that it sounds like my injectors causing the problems after the overheating but, i have this feeling that it was the second hand pistons that i used..

Just wanted to share this with you guys.. maybe someone in the future..

Cheers.
 
#15 ·
Hi all.

Just another update.
I have done another complete overhaul again on this engine.
Machined the block to 20 tho and installed brand new Arco pistons and rings, new bearings and a new borg warner turbo cartridge.
And i am still struggling with blowby... Dont know what else to do anymore.. Seems like this motor just dont want to get rid of the blowby.
Thanks to everone for your help..

Cheers Hans.
 
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