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General Information => Troubleshooting => Topic started by: vern on October 14, 2008, 06:06:07 am
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I have a mkII jetta TD, I know i should assume rings, but what are some other major causes of burning oil in these engines, the car runs GOOD, pretty peppy and no starting issues or running problems? could it be coming in through the turbo or valve seals? I do not leak any, but I go through about 500-750 ml of engine oil per tank of diesel...
Hitting the gas hard makes it give some nice smoke behind me... gets worse in idling traffic.. what you guys thing? I dont really care about the smoke, but worried about being pulled over casue of it.
If i want to do compression test, is the process to take out the injectors and test it from there? what should compression be (do I need a special compressor for the diesel engine?) Any easy way to test turbo play or seals or whatever? I don't really have much diesel experience but always willing to learn :P
:lol:
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Well first off, what color is the smoke?
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white or blue.. I know its oil, it goes down quick, anti freeze isnt going down and its still getting good MPG.
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hard acceleration will burn your oil unless you use a good synthetic oil. new rings is a cheap fix, but you'll burn oil until they seat properly...
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if its not affecting performance i would rule out rings..maybe check the intake for oil residue from a leaking turbo shaft seal
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if its not affecting performance i would rule out rings..maybe check the intake for oil residue from a leaking turbo shaft seal
um... pretty sure performance can be excellent even if the rings are bad... now if a ring is broken thats a different story.
half decent compression rings with bad oil control rings = good performance, with oil consumption. don't forget that these motors will actually burn the motor oil as fuel, so that might add a little power, masking the problem. i had a motor that had new rings put in and the power was great, but it consumed oil. took about a year before oil consumption dropped to acceptable levels.
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I'll second that comment.
On my last engine compression was below 200 across the board and yet once started it ran great!
Just was hard to start.
Found a broken ring land and the second ring was stuck in the piston's on all but the broken ring land one.
Then the end gap was WAY off to aid in the problem.
So ya, it can still run fine with messed up rings.
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hmmm ok, so onto the other questions , how would I properly pressure test the pistons and what should the compression be? I'm assuming the injectors have to be removed and just do it through that hole.
Also, It was really really smoking in the way home from work.. so I pulled the boost enrichment line off after I got home just for fun, and it seemed to take away alot of the big clouds of smoke, I didn't really drive it really far but it helped ALOT. Could it be running too much boost? I really dont know what the person before me has done to increase performance, but I know things were done, and its a lot peppier than my other car(i was told it has a giles performace pump, its had the governor mod etc)....
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my old 1.5 n/a started to run away but ran great otherwise. its was damned fast for the engine.
re-ringed it - fixed all the oil consumption problems.
funny thing was, ring gap was way big with the old rings - like 2.5mm!
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i bet if you added one of those oil breathers to allow the blowby to leak back into the block, your oil consumption would go wayyyy down...
as to the LDA issue you have - someones messed with the starwheel inside of it to add more fuel than can be burned. this can be tweaked quite easily though just by taking off the top cover plate, and giving it a few turns. i forget which way is less fuel, but i think its counter clockwise. just keep track of how much you turn it so you can go back. should make a click, so you can go by how many clicks you turn it.
in the meantime, smooth acceleration will keep oil consumption down. if you mash the pedal and the car doesnt go any faster, thats a good indication that you need to ease off because the car just simply won't go any faster :lol: newer diesel/gasoline cars use oxygen sensors to compensate for this, whereas we need to use our brain & right foot :wink:
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in the meantime, smooth acceleration will keep oil consumption down. if you mash the pedal and the car doesnt go any faster, thats a good indication that you need to ease off because the car just simply won't go any faster :lol: newer diesel/gasoline cars use oxygen sensors to compensate for this, whereas we need to use our brain & right foot :wink:
but I like to mash the pedal :cry:
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um... pretty sure performance can be excellent even if the rings are bad... now if a ring is broken thats a different story.
half decent compression rings with bad oil control rings = good performance, with oil consumption. don't forget that these motors will actually burn the motor oil as fuel, so that might add a little power, masking the problem. i had a motor that had new rings put in and the power was great, but it consumed oil. took about a year before oil consumption dropped to acceptable levels.
oh really..i never really thought about that..i apologize for my ignorance
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One way to determine if it's the valve seals: if the car smokes badly ONLY when you first start it in the morning, and when you accelerate after a stop, it's probably valve seals. Those are the symptoms I've seen on my diesels, and on the old gassers too.
Now, a word of caution. If the valve seals are toasted, then it could possibly smoke all the time.
In other words, if you only get periodic smoke (just upon normal accelartion after idling at a stop), or upon startup, then look to the valve.
If you get smoke all the time, I'd think rings.
If you get BLUE (not black) smoke under hard acceleration, then I'd think turbo.
Valves and turbo are prety easy to rule out by 1) determining the pattern (if any) to the smoking, and 2) inspecting the turbo for play.