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UPDATE : 6.2 burns oil / or smokes

sweetk30

sweetk30

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6.2 I got here recently burns oil left bank . cleans up a little after running but still there even after 5min running in park . cant test drive no plates and frame cracked at steering box bad . have not ordered kit to fix yet if engine needs major work . http://coloradok5.com/forums/showthread.php?t=314807

found its a 6.2 from 85 in the truck and I think it come from a med duty application . as it has a j code intake non emmisions . and there was a used engine recipet in the paper work of the truck .

also pulled and did new glow plugs . ac 60g and left bank ones had oil on them . right bank basicly dry as a bone .

it has true duel exhaust system . hence the left bank only .

also did new rubber return hose kit for the injectors as one line had a pad spot and was dribbling fuel when running and also let drain back when off.

it runs smother now and idles better now with new line kit.

fires right off just fine and revs up good.
 
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All four injectors have oil on them? Seems odd if the right bank has none. Usually when the rings are going they tend to go kind of evenly with one or two cylinders showing first but randomly on both banks. I think I've heard #8 tends to go first for some reason but still only one bank and the total bank seems odd. Could be valve seals were changed on the right bank at one time but not the left. If it starts good both hot and cold then usually it's not the rings in my experience. Did you pull the oil fill plug off and see how much it blows. If it looks like the Wabash Cannonball coming down the tracks then it has pretty good blow by.
 
My '85 Suburban smokes out of the drivers side tail pipe too,but not the right side (as much anyway)...it doesn't have any excess blowby from the oil filler cap and someone replaced the CDR valve and all the plumbing to it is clean,so I dont think its bad rings..it runs smooth,if it had low compression I would think it would idle roughly or you'd hear it speed up while cranking when it comes to the compression stroke on that cylinder..

Its hard to tell if a diesel is burning oil when it burns oil as fuel to start with..

I'm just going to run it and see what happens--for all I know it might clear up after it gets put back on the road and driven..I also do not know whats in the fuel tank,I do know the former owner admitted to adding some filtered used motor oil,kerosene,and who knows what else,maybe veggie oil to the diesel..until all that is used up I wont really be able to tell whats making the left bank smoke...maybe it needs valve stem seals,or a return hole in the head is plugged with crap and letting oil puddle up around the valves,I had a 350 that did that,thought it was going to need rings and a complete overhaul--15 minutes with a coathanger to fish out a bunch of aluminum foil "caps" from oil containers that were in there fixed it!--,and the holes were sludged shut....
 
so if I was to need valve seals how hard are they to change with the head on the engine ?

just like a gas job ?

any tips/tricks ?

wouldn't surprise me if returns pluged on driver head and backing up the oil . I have seen this before on a few gas jobs.
 
I'm not sure if the pistons come up high enough to just let the valve sit on the top but I think they do. There has got to be a thread on the net to tell you how to do them. The oil staying on top is a strong possibility for sure. A good way to check is to check the oil level cold after the motor has sat for a day or more then start it and let it run for a while. Then check the oil after 5 mins or so and see if there is a big difference on the dip.
 
diesel4me said:
Its hard to tell if a diesel is burning oil when it burns oil as fuel to start with..
Click to expand...

My thought exactly. If you aren't driving it/running it up to temp, what makes you think you're seeing more than just plume of oil smoke common to cold 6.2 engines? :dunno:
 
5-10 min running at farm in front of barn and right bank is clear as ski and left bank is white and smoking .
 
Valve seals should not be any harder than a gas engine. But, I would want a compression check. Harbor freight sells a decent diesel compression guage.
 
Copied from another diesel site:

White smoke:

White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
· Incorrect fuel injection timing
· Defective fuel injectors
· Low cylinder compression

Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.


Maybe injectors were changed on the right bank but not on the left and they're worn. Like was said earlier, a compression test would be really good to determine the issue and not too much cost. The socket for the injectors is kind of hard to find without ordering it or getting it from a SnapOn or Mac tool guy.
 
A way to test to see if it's an injector is to crack each injector line nut one at a time until you get a fuel drip and see if the smoke stops. Do this on each injector and if it stops, you've found the bad injector. You might want to do this before a compression test as you don't need any special tools to crack the nuts. I think the nuts are metric but 11/16ths fits if I remember correctly. The motor might stumble some when you crack the line but if the smoke stops you still found the weak injector causing you the problem. The whole process should take less than 10 minutes to test all 4.
 
fired it up today been sitting for around 5 days no start.

little cranky starting I assume from home made fuel jerry can system drain back . but once fired it runs smooth / rev's fine.

running time 5-8 min its not bad on left bank . but if you rev it up or romp on it boy it turns white. also smells rich / burn eye's lack of better smell reference on diesel stuff . I am basicly a gas engine guy .

did check coolent . seems to be swirling a lot in the rad tank . also down around 1qrt so I topped it off. and when running it seems to be real jumpy liquid not like a gas engine cooling system when running .

I took my IR temp probe gun with me . left bank is around 15-20* cooler than right bank average temps.

also average on each bank per cyl was no more than 15-20* difference also .

at this point if I cant figure it out for a cheep fix its not worth my time to tear in to it and fix it and resale it to make any profit. if the engine ran good I still need over 200 in parts for the broken frame and 4-5 hrs shop time to bolt the steering box back on.

I wont get hurt with the price I paid for it if I sell it whole or part it out . so I am not crying about that .

just at a loss on what to do as I don't play with diesel stuff much if any at all. and most of these trucks are long gone around here by now from major rust and finding anyone short of shop labor time to help is hard to find .

oh well time to not think about it for a bit I guess. :popcorn:
 
I noticed the coolant seems to move rapidly in my diesels compared to a gas engine too--maybe the water pump puts out more flow than a typical small block,(they do have huge radiators!)--and the vibration of the diesel makes it look "jumpy" as you described..neither of mine use any coolant to speak of,my pickup does weep some at the thermostat crossover where it meets the intake,but I've never added much more than a quart or two over several years to it..

Unless your seeing steam out the tail pipes or its overheating & boiling over,I doubt the head gaskets or heads are bad,though the 6.2 is noted for head gaskets failing ,and I've read almost all the heads crack between the valves,but rarely lose coolant there...with 400 lbs of compression,its not hard to tell if one cylinder is leaking into the one next door,and usually you'll see coolant spitting out the tailpipes or see some in the oil if it has a bad gasket..

I would bet if you were to use the truck daily,it eventually would get better,not worse...since I started using my truck "daily" instead of just a "yard plow",I noticed its starting up easier,idles smoother (most of the time!) and one day when I took it up to 65 mph for the first time in years and had to pass a slowpoke up a hill,when I booted it in second gear at 45 or so and let it wind up a bit,I felt something like a "surge" of sudden HP,then it made some pinging noises--..

I thought I blew it up,or maybe it was starving for fuel,but evidently some chunks of carbon broke free and got crunched up and blown out the tailpipes,I saw a lot of black stuff coming out of the back....when I got off the highway at the next exit and had to stop,I noticed it idled smoother than it had in a long time,and it didn't have as much "diesel clatter" at idle either..I wouldn't doubt my using it just to chug around town and push snow at fast idle let a lot of soot build up under the intake valve heads or something..
 
If you want to get a compression test on it, I could loan you my diesel compression tester the same way autozone loans tools. Just leave a refundable deposit of the replacement cost and pay shipping both ways.
 
thanks Kenny . I got guys I can barrow tool from . they dig it out of there old stash from back in the day .

got overtime at work this week and lots of time driving tow truck . so I have time to decide what I am going to do .
 
diesel4me said:
I would bet if you were to use the truck daily,it eventually would get better,not worse...
Click to expand...

I agree. My '83 used to produce copious amounts of smoke on startup. Black, Blue, and White smoke. Used to be that I could start up in a parking lot and I'd be driving through 50 feet of haze to get to the roadway. The smoke got better for the first 3 or 4 thousand miles, and now it isn't a bother at all (although it is still noticeable). Having put the '84 on the road now (the P/O had it in storage), I'm starting the cycle over again. And it's getting better like the '83 did.

So don't be alarmed if it smokes a bunch after sitting. And do remember that tier zero diesel engines (like the 6.2) never really stop smoking, even at their best. That's why I named my truck Smaug. :D
 
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