Trying to narrow down causes of white smoke.

[ihuntbear]

is there a turbo on that unit.if so ,a blown turbo can blow white smoke and loss of power but still run rough

 

[sqidget]

If the injector coming out of the rear cylinder is wet, I am assuming with fuel due to the fact that the smoke stops. Low compression is the culprit. Does it run good initally then start acting up or did this happen instantly and will not stop now hot or cold? If it starts ok then gets worse check the valve adjustment. a valve adjustment with insufficient clearance can hold a valve slightly open. If run like this you can burn a valve on the seating surface and damage the head. I really believe a compression test is needed and possibly a leakdown test. Having smoke and wet nozzle indicate the fuel system is injecting fuel, but with low compression it is into a cold cylinder, causing white cold smoke. If you need to improvise a leakdown test you can pull the valve cover, bring the rear cyl onto tdc compression stroke, remove the injector, remove the air cleaner, blow into the injector hole with a rubber tipped blow gun. If you hear air out the exhaust, its a bad valve, if you hear it out the intake it is a valve. if it is either, remove the rocker arms as an assembly, and retest. If it goes away it is a adjustment or you were not on tdc comp. If not pull the head. If it escapes into the crankcase it is a piston or rings.
This is a half-assed test method and I firmly suggest a true compression and leakdown test.

 

[jlrsn]

I don't know anything about your engine but I do have over 50 years troubleshooting engines. This is a shot in the dark but you might have a hole in the piston or a broken valve. If you don't have a diesel engine compression tester can you remove the rear ignitor plug and pump air into that cylinder. Some air nozzles have a rubber end that will allow you to pressurize that cylinder. If air can be pumped into the rear cylinder remove the oil filler cap and if you have air hissing out you either have a hole in your piston or seized rings. If the hissing of air is coming out of the exhaust stack you have a broken, burnt, or seized exhaust valve. If the hissing is coming out of the intake you might have the same problems with the intake valve. Like I said it is a shot in the dark but I've used that method successfully for years. Are the valves adjustable in that engine?
Good luck,
Jim

 

[joeyb]

is there a turbo on that unit.if so ,a blown turbo can blow white smoke and loss of power but still run rough

I wish. No turbo on this one.

 

[joeyb]

If the injector coming out of the rear cylinder is wet, I am assuming with fuel due to the fact that the smoke stops. Low compression is the culprit. Does it run good initally then start acting up or did this happen instantly and will not stop now hot or cold? If it starts ok then gets worse check the valve adjustment. a valve adjustment with insufficient clearance can hold a valve slightly open. If run like this you can burn a valve on the seating surface and damage the head. I really believe a compression test is needed and possibly a leakdown test. Having smoke and wet nozzle indicate the fuel system is injecting fuel, but with low compression it is into a cold cylinder, causing white cold smoke. If you need to improvise a leakdown test you can pull the valve cover, bring the rear cyl onto tdc compression stroke, remove the injector, remove the air cleaner, blow into the injector hole with a rubber tipped blow gun. If you hear air out the exhaust, its a bad valve, if you hear it out the intake it is a valve. if it is either, remove the rocker arms as an assembly, and retest. If it goes away it is a adjustment or you were not on tdc comp. If not pull the head. If it escapes into the crankcase it is a piston or rings.
This is a half-assed test method and I firmly suggest a true compression and leakdown test.

Ok, here's what I found out. Adjusted the valves to .2MM and it still ran terrible. Pulled the glow plugs and set front cylinder to TDC. Used a rubber tip gun to blow air in and the wrench I was using to rotate the motor flew out of my hand. No sound of air anywhere...this one seems air tight as it was extremely difficult to hold the nozzle tight in the glow plug hole and also hold the wrench on the crankshaft pulley. Then I tried the rear "problem" cylinder at TDC and could feel air coming out of the air cleaner horn. I then removed the rocker arm assembly and tried both cylinders again and the results were the same. I am assuming that regardles of where the piston is in the cylinder....if the rocker arms are off (both valves closed all the way) and I can feel air out the intake then the intake valve is the problem?

 

[joeyb]

I don't know anything about your engine but I do have over 50 years troubleshooting engines. This is a shot in the dark but you might have a hole in the piston or a broken valve. If you don't have a diesel engine compression tester can you remove the rear ignitor plug and pump air into that cylinder. Some air nozzles have a rubber end that will allow you to pressurize that cylinder. If air can be pumped into the rear cylinder remove the oil filler cap and if you have air hissing out you either have a hole in your piston or seized rings. If the hissing of air is coming out of the exhaust stack you have a broken, burnt, or seized exhaust valve. If the hissing is coming out of the intake you might have the same problems with the intake valve. Like I said it is a shot in the dark but I've used that method successfully for years. Are the valves adjustable in that engine?
Good luck,
Jim

The intake valve seems to be the problem. Range of motion appears fine as it looks no different then the other three.

 

[gerryt]

Joey, I've worked on a lot of these. To determine which cylinder is the culprit remove the exhaust manifold and start it up, then you'll see which one is the culprit. I suspect at the very least a head gasket but at worst the head is likely cracked.
One way to check for this is to start it up, let it warm up and top up the radiator then you can check for bubbling in the rad. Although this test is not conclusive it is a good indicator.
The L175/L185's are prone to cylinder head cracking! This is due to the fact that they do not have a water pump but rather are designed to use convection (or thermo syphon as some call it) for cooling. The principle is that hot water rises & cold water drops in the closed system thereby creating reasonably good flow once the engine warms up.
That being said, if the engine is not warmed up and the tractor is put to use before operating temperature is attained the coolant is not yet flowing and hot spots occur atop of the combustion chamber causing the head to crack due to extremes in temperature change when the flow starts.

But don't despair, if you do need a new head & gaskets I can help as I usually have these in stock. Feel free to contact me with any questions.

Gerry Trudeau
e-mail tractors@mts.net
web www.used-tractors.ca

 

[Sniggle]

A new pope was elected?








(Sorry, I couldn't help myself)

 

[sqidget]

Joey,
You are correct in stating that with the rocker arm assy removed it no longer matters where in the rotation the engine is. You will have to pull the head and inspect the valve and the seat to determine why it no longer seals.

 

[joeyb]

Thanks again for all the help. I pulled the head and now the plot thickens. The combustion chamber looks as if its rusted away. The piston has a lot of thick unburned fuel on it but is otherwise fine and so is the cylinder wall. What do y'all make of this? I'm assuming this head is junk?

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