Technical Head gasket, piston ring or sticking valve problem?

[Steely]

Re: Head gasket, piston ring or sticking volve problem?

http://cgi.ebay.co.uk/Sykes-Pickava...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

compression tester, it does sound very much like heavy breathing to me, the only reason i can think that it happens sub 1000 rpm, is down to the fact the compression cycles are longer so give it time too seep past the rings, once up and running, the compression stroke is so short time wise it doesn't give it chance to blow by,,,

a good garage should be able to do a compression test,


but as PNL mentioned, I would recommend doing a forte flush, try cheapest options first, it could be a stuck compression ring, but it could be many things, scoured piston/cylinder, slapping piston, but its all speculation so dont jump to conclusions! i as lead to believe i needed a new body computer for the stilo and all it was, was a poxy parking sensor control!

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

but as PNL mentioned, I would recommend doing a forte flush, try cheapest options first, it could be a stuck compression ring, but it could be many things, scoured piston/cylinder, slapping piston, but its all speculation so dont jump to conclusions! i as lead to believe i needed a new body computer for the stilo and all it was, was a poxy parking sensor control!

Cheers!

I have changed the oil with engine flush prior new oil. Problem still there but seems a bit different.

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

Here is my summary of symptons and the guess of the root cause with help from everyone:

Sympton 1). Air coming out from oil cap when RPM < 1000
==> Piston ring problem. Only when RPM < 1000 as compression cycle time is long enough to let the air seep out

Sympton 2). White/Grey-ish smoke in the morning when engine is cold. (so far, happen three times only)
==> Oil seep into cylinder over night, head gasket failure

Sympton 3). Engine seems lack of power for 0.1 second at 1800 RPM. Specially when engine is cold.
Theory 1==> Turbo is on its way out.
Theory 2==> Air get into crankshaft, oil evaporate into turbo intake. When turbo kick in at 1800 RPM. Too much oil into cylinder cause non-full combustion, hence lack of power. When engine is hot, all the oil are burt out. Back to normal.

Sympton 4). Losing oil slowly. Obvious around turbo.

Sympton 5). Black smoke when accerate fast.
==> Common sympton for all diesel engine?

Other info.
a). Fiat dealer use computer to diagnose engine. Nothing wrong. They only guess it's head gasket failure. Need to open engine to check ;-(
==> I think this should rule out glow plug problem. Otherwise, it should pick up from the computer diagnose.
b). No over heat, no lost of coolant at all.

 

[Steely]

Re: Head gasket, piston ring or sticking volve problem?

have you had the air filter out?? check for engine oil contamination, this would be caused by blowby on the piston rings, usually you will get a very slight emulsion...


just dont make any quick decisions, sometimes its better to stand back and look at it another day,,, and im sure many with help on here, !

 

[fiat brava jtd elx 105]

Re: Head gasket, piston ring or sticking volve problem?

this is a way out theory but still check the air flow metre and waste gate on the turbo. as the problem is worse when cold just check the dash lights and see if a glow plug warning light flashes for more than 30 seconds when starting.
if yes the glow plugs mayb on there way out as they dont last forever. If u do a compreesion test just b careful m8 as its a bit more dangerous than doing a petrol model.

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

have you had the air filter out?? check for engine oil contamination, this would be caused by blowby on the piston rings, usually you will get a very slight emulsion...

I've checked the air filter. Nothing wrong with it. However I did see some little oil leak around the intake pipe from turbo.

As for the oil. There is no water (coolant) in the oil. No sign of losing coolant at all. I think the coolant system is perfectly contained. In such case, could broken piston ring cause the emulsion as well?

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

I have found a way to reproduce the smoky sympton. It happened when:

1). Car parked overnight.
2). Rev the engine right after start up.
- If I wait for the engine to run at idle speed for couple minutes, the smoky sympton won't come out.


Previously, I thought it's head gasket fail. Oil leak into cylinder. So the sympton should be: The longer I park the car, the more smoke I got.

This is not true. To get lots of smoke, simply start the car and rev engine immediately. On the other hand, if I let the engine run at idle speed for 5 minutes, smoke problem won't come out.

I am getting to feel this is something to do with turbo. Or... to the worse case. Both head gasket failure and turbo problem :bang:

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

this is a way out theory but still check the air flow metre and waste gate on the turbo. as the problem is worse when cold just check the dash lights and see if a glow plug warning light flashes for more than 30 seconds when starting.
if yes the glow plugs mayb on there way out as they dont last forever. If u do a compreesion test just b careful m8 as its a bit more dangerous than doing a petrol model.

Glow plug warning light is normal. What is turbo waste gate for? Thanks.

 

[Argonought]

Re: Head gasket, piston ring or sticking volve problem?

Thanks for your comment. I haven't put my car into garage yet... as the problem goes away after warm up.

Is that final a summation for this thread then

You've only mentioned two things which I would question:

• High oil consumption :chin: (should be low on a JTD)
• Weak on hills (this is very very wrong as climbing ability of a JTD is quite simply awesome)

Forget about the turbo waste gate - you haven't got one

 

[john55]

Re: Head gasket, piston ring or sticking volve problem?

Forget about the turbo waste gate - you haven't got one

What does the boost control valve actuate then?

I think you will find it is the wastegate.

 

[john55]

Re: Head gasket, piston ring or sticking volve problem?

Try disconnecting the air inlet pipe off the manifold (next to the EGR valve) and starting it from cold, wait till the smoke clears, stop it, leave it, start it again next day. If you don't have smoke, then it is coming in through the inlet pipework (ie from the turbo or breather / vapour trap pipes). If you have smoke, it is coming from inside the engine, i.e. piston rings, valve guide seal etc.

 

[Argonought]

Re: Head gasket, piston ring or sticking volve problem?

I think you will find it is the wastegate.

To be pedantic about I think you'll find the JTD115 doesn't have a waste gate in the excepted sense although I concede it uses a mechanism that accomplishes much the same task.

 

[fiat brava jtd elx 105]

Re: Head gasket, piston ring or sticking volve problem?

every turbo has a waste gate other wise the turbo would just spin faster and faster and then blow up

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

Try disconnecting the air inlet pipe off the manifold (next to the EGR valve) and starting it from cold, wait till the smoke clears, stop it, leave it, start it again next day. If you don't have smoke, then it is coming in through the inlet pipework (ie from the turbo or breather / vapour trap pipes). If you have smoke, it is coming from inside the engine, i.e. piston rings, valve guide seal etc.

I like the idea but I have trouble to locate the pipe you mentioned.

On the other hand, I save 2 vapour recovery pipe on the top of the engine. I am puzzled about their function and design.

1). The red one in the font. Why does it directly get into the turbo intake? Oil vapour will get into the turbo and then to the intake directly....

2). Where is the blue vapour pipe goes to? I saw it get into the engine in back.

Thanks again in advance.:worship:

 

[Argonought]

Re: Head gasket, piston ring or sticking volve problem?

The JTD80 does indeed have a waste gate but not so the JTD115 which is fitted with a VGT (variable geometry turbo)

This the the actuator controlled directly by the overboost valve and you can just see the actuating rod (top middle). Notice the tube at the bottom which returns to the overboost valve (otherwise known as a VGT solenoid)

This directly controls the geometry of the blades on the turbo and therefore controls excessive boost in a much more efficient way than a waste gate.

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

Another question about my dying stilo...

I can reproduce the problem:

When start the car, turn the key to 'start' immediately without waiting for the engine check, glow plug indicator go off...etc. This cause my JTD engine unable to start up properly. Even after couple minutes, restart again with proper check done. It still unable to start... It just like a petrol engine without spark plug. There is no ignition. Eventually, after long wait and long keep starting it. It get back to normal.


Don't quite understand the reason. Any idea?

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

I like the idea but I have trouble to locate the pipe you mentioned.

On the other hand, I save 2 vapour recovery pipe on the top of the engine. I am puzzled about their function and design.

1). The red one in the font. Why does it directly get into the turbo intake? Oil vapour will get into the turbo and then to the intake directly....

2). Where is the blue vapour pipe goes to? I saw it get into the engine in back.

Thanks again in advance.:worship:

Forgot the diagram... Here it is.

 

[shiningliao]

Re: Head gasket, piston ring or sticking volve problem?

This directly controls the geometry of the blades on the turbo and therefore controls excessive boost in a much more efficient way than a waste gate.

Wow, thanks! However.... geometry of the blades on the turbo....

This is beyond my knowledge. Can you explain what exactly is that blade? I am quite interested to know these stuff.

 

[Argonought]

Re: Head gasket, piston ring or sticking volve problem?

When start the car, turn the key to 'start' immediately without waiting for the engine check, glow plug indicator go off...etc. This cause my JTD engine unable to start up properly. Even after couple minutes, restart again with proper check done. It still unable to start... It just like a petrol engine without spark plug. There is no ignition. Eventually, after long wait and long keep starting it. It get back to normal.


Don't quite understand the reason. Any idea?

If your JTD engine is cold then you should always allow time for the heater plugs (glow plugs) to warm the cylinders (so the fuel will ignite). This is the same for any diesel.


The large intake (about 8cms dia.) tubing that john55 refers to is towards the back and you need to remove it from what looks like a carburetor on the inlet manifold. It will be easier if you remove the engine cover first. It sounds like a good test to me so I'd do it but never drive with it like that as it's taking in completely unfiltered air.

 

[Morty Mort]

Re: Head gasket, piston ring or sticking volve problem?

The killer reply: Is the oil filter fully tightened? If not it causes a pressure leak and oil evaporates and spills out - but you will never notice anything apart from believing the engine drinking oil. Also ceck if the seal is moist or dried up. Or if there is an extra seal from an earlier change. If so, remove it as it will never tighten correctly.

Just trying with an extremely simple solution.

M.