White Smoke from Exhaust
Discussion
Hi guys,
I need some advice on how to deal with the following problem. I may have added a bit too much oil in the dry sump oil tank. Subsequently the exhaust started spewing white smoke. I'm pretty certain it's excess oil that's being burnt in the engine and then leakes into the exhaust cos I'm getting sooty oily condensation at the tailpipes.
What's the best way to deal with this issue? Keep the engine (LS-7) running until it's all burnt off? Am just worried that I could ruin the engine that way. Do I need to open up the engine to clean it?
Cheers,
Willy
I need some advice on how to deal with the following problem. I may have added a bit too much oil in the dry sump oil tank. Subsequently the exhaust started spewing white smoke. I'm pretty certain it's excess oil that's being burnt in the engine and then leakes into the exhaust cos I'm getting sooty oily condensation at the tailpipes.
What's the best way to deal with this issue? Keep the engine (LS-7) running until it's all burnt off? Am just worried that I could ruin the engine that way. Do I need to open up the engine to clean it?
Cheers,
Willy
I am not familiar (yet) with the LS7 engine, but..
Well when I had this issue once on a racing car with a dry sump system, I simply ran the engine for a few seconds, switched it off, and before the oil had a chance to drain out of the tank I sucked some out with a hand suction-pump.
That way, you can see how much you are removing.
Hope that helps
Regards
Kelvin
Well when I had this issue once on a racing car with a dry sump system, I simply ran the engine for a few seconds, switched it off, and before the oil had a chance to drain out of the tank I sucked some out with a hand suction-pump.
That way, you can see how much you are removing.
Hope that helps
Regards
Kelvin
wb200 said:
I may have added a bit too much oil ... I'm pretty certain it's excess oil that's being burnt in the engine
I suggest you measure the oil level properly to confirm that theory. If you have a dry sump system I wouldn't have thought overfilling would cause a problem until the reservoir literally overflowed. (With a wet sump system it's a bit different as the excess oil can get whipped up by the crank.)ETA: If it really is burning off the excess oil, I'd have thought that would tend to coke up the inside of the chamber which is not ideal.
Edited by GreenV8S on Saturday 30th August 18:57
Excess oil smells distinctly of burnt oil and usually produces grey (gray) smoke.
Excess fuel is generally black smoke.
Coolant (antifreeze/water mix) has a 'sweet smell' when exhausted through a running engine and can produce 'steam'
Pure water, (normally condensation build-up in the exhaust system shortly after start-up), has the same 'exhausted appearance' as steam and is normally odourless.
But please dont sit for hours sniffing your tailpipes.....thats a job for the ex-mother-in-law!!!
Good luck.
Excess fuel is generally black smoke.
Coolant (antifreeze/water mix) has a 'sweet smell' when exhausted through a running engine and can produce 'steam'
Pure water, (normally condensation build-up in the exhaust system shortly after start-up), has the same 'exhausted appearance' as steam and is normally odourless.
But please dont sit for hours sniffing your tailpipes.....thats a job for the ex-mother-in-law!!!
Good luck.
i agree with Mr Suntiger...
only time i have had 'white smoke' was when a cylinder head went...i looked like an extremely low flying Red Arrow for about a mile until i could stop safely
check the coolant, is the temperature good?
you may be able to see oil contamination in the header but personally, i would do a compression test
only time i have had 'white smoke' was when a cylinder head went...i looked like an extremely low flying Red Arrow for about a mile until i could stop safely
check the coolant, is the temperature good?
you may be able to see oil contamination in the header but personally, i would do a compression test
wb200 and i are pretty sure it is engine oil, as the smoke condenses into this brownish fluid which is found at the bottom of the inside of the exhaustcollectors. My guess is too much engine oil in the external
oil tank, and the top hose probably thus sucked the oil into the
pistons(??).
yes, we shouldn't be sniffing it too much.. though we were expecting to
burn it off "lightly" without much revving, so far about 10 engine starts
at 2-3mins each time.
Re the oil cap, there is a oil cap on top of the LS7 engine but
based on forums was advised not to remove it as it may break off
and fall in.
Will need to check the spark plugs as you guys suggested to see the
condition and get more confirmation that it is engine oil.
By the way, there was a suggestion to handpump the oil out.
Sounds like a good idea, how do you do that?
Or anyway to blow dry the combustion chamber out with air?
oil tank, and the top hose probably thus sucked the oil into the
pistons(??).
yes, we shouldn't be sniffing it too much.. though we were expecting to
burn it off "lightly" without much revving, so far about 10 engine starts
at 2-3mins each time.
Re the oil cap, there is a oil cap on top of the LS7 engine but
based on forums was advised not to remove it as it may break off
and fall in.
Will need to check the spark plugs as you guys suggested to see the
condition and get more confirmation that it is engine oil.
By the way, there was a suggestion to handpump the oil out.
Sounds like a good idea, how do you do that?
Or anyway to blow dry the combustion chamber out with air?
As mentioned, remove the spark plugs and inspect them. If there's oil in the combustion chambers they'll show it.
Eta, if there's excess oil in the dry sump why not undo a union and just drain some out? You may need to tip the car slightly.
Eta, if there's excess oil in the dry sump why not undo a union and just drain some out? You may need to tip the car slightly.
Edited by Boosted LS1 on Monday 1st September 17:16
Oil will be blue/grey smoke not white.
It was stated that this was condensing into a black slime. Oil would not condense it would just be oily. Condense implies water.
Have to agree with others here that we are looking at a water leak where the inlet manifold meets the heads or at worse head gasket failure/cracked block.
Steve
It was stated that this was condensing into a black slime. Oil would not condense it would just be oily. Condense implies water.
Have to agree with others here that we are looking at a water leak where the inlet manifold meets the heads or at worse head gasket failure/cracked block.
Steve
Just a further point, if you have the plugs out and access to a compression tester, it may be worth doing a quick compression check.
I have seen engines that have a weak or misfiring cylinder produce the black watery residue you mentioned. Its hopefully nothing to do with low compression but worth a quick check whilst the plugs are out!
Slight misfires are far less obvious on a V8 motor.
Good luck.
I have seen engines that have a weak or misfiring cylinder produce the black watery residue you mentioned. Its hopefully nothing to do with low compression but worth a quick check whilst the plugs are out!
Slight misfires are far less obvious on a V8 motor.
Good luck.
Thx guys for all the above. Update for you.. still diagnosing.
I pulled out one of the spark plugs (didn't hv much time after work),
specifically the left side rearmost plug.
Spark plug basically looks newish and shiny except for the whole
top/tip down to say the first thread -- this area has some fluid.
brown/black oily?
I'm gonna try to post a pic or two.
And pull out the rest of the plugs tonight.
Unfortunately don't have a compression tester at the moment...
(fyi, I did drain the whole system by removing the two plugs
on the dry sump. Filled the external oil tank up, and counted
the litres this time -- 6litre was enuf to get to the ultima
oil tank baffle, without going to the 7.57L (8 quarts) normally
written re LS7 sights).
I pulled out one of the spark plugs (didn't hv much time after work),
specifically the left side rearmost plug.
Spark plug basically looks newish and shiny except for the whole
top/tip down to say the first thread -- this area has some fluid.
brown/black oily?
I'm gonna try to post a pic or two.
And pull out the rest of the plugs tonight.
Unfortunately don't have a compression tester at the moment...
(fyi, I did drain the whole system by removing the two plugs
on the dry sump. Filled the external oil tank up, and counted
the litres this time -- 6litre was enuf to get to the ultima
oil tank baffle, without going to the 7.57L (8 quarts) normally
written re LS7 sights).
Excuse the format.. first time posting..
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[/URL]Edited by DiscUltima on Tuesday 2nd September 05:35
wow they are black,was that running on tick over for a while before you shut her down and refired up overfilled with oil??
can you email me a better picture and i might be able to advise you further..
most guy here have got the right idea, you need to get compression tester while plugs are out anyway.. they are only £10-£15 from rip off halfords but will certainly tell you if everything ok..also does your engine breathe heavy??have you removed the radiator cap and looked at coolant? is there an oily film on the edge of the bottle inside just above level or oil/slug in coolant..
also i to to ask but how long was engine running to get white smoke?? and how long have you run it since(its not just condensation as weve been having alot of damp days recently and my V8 smokes sometimes as well)?
my email is dom@34coupe.fsnet.co.uk
dom
can you email me a better picture and i might be able to advise you further..
most guy here have got the right idea, you need to get compression tester while plugs are out anyway.. they are only £10-£15 from rip off halfords but will certainly tell you if everything ok..also does your engine breathe heavy??have you removed the radiator cap and looked at coolant? is there an oily film on the edge of the bottle inside just above level or oil/slug in coolant..
also i to to ask but how long was engine running to get white smoke?? and how long have you run it since(its not just condensation as weve been having alot of damp days recently and my V8 smokes sometimes as well)?
my email is dom@34coupe.fsnet.co.uk
dom
The LS7's dry sump is not exactly like other dry sumps.
The oil will drain into the sump on the engine when the engine is not running. Hence, the tendency to over fill it.
The engine should be run for a few moments, turned off, then the oil checked immediately in the dry sump reservoir.
Also it's best to only use max of 5w30 oil as the pump is driven at crankshaft speed instead of half speed like a normal dry sump. Heavier oil may cavitate the pump..
At least one guy has overfilled it til the valve cover gaskets blew out.
Thanks
Jeff S
The oil will drain into the sump on the engine when the engine is not running. Hence, the tendency to over fill it.
The engine should be run for a few moments, turned off, then the oil checked immediately in the dry sump reservoir.
Also it's best to only use max of 5w30 oil as the pump is driven at crankshaft speed instead of half speed like a normal dry sump. Heavier oil may cavitate the pump..
At least one guy has overfilled it til the valve cover gaskets blew out.
Thanks
Jeff S
This may sound strange, and somewhat unlikely. From an earlier post, it looks like your oil reservoir was plumbed (vented) back into your throttle body. Any chance you are getting a small amount of oil pushed out the tank and into your throttle body?
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Randy
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Randy
Well guys, managed to put in another 2hours after work.
I did have a word with Dave at the factory.
Still haven't gotten a compression gauge yet but did the following.
Took all 8 plugs out.
Cranked the engine about 3 x 10 seconds (can see the pistons
going up and down through the sparkplug hole, as well as
feel the air being blown/pushed out).
External oil tank toptube return to engine / intake manifold -
I manually blew into it (just incase any unlikely blockage)
Fyi, engine had only needed to be turned on to get the white smoke.
And we have been running it inside, haven't done a 15-20 constant on,
nor an outside run yet.
Suntiger(Dom), yes they were black (oily/filmy ard the top 2-3 threads
and the spark plug tip and curve were black as well). I cleaned
the best I could using paper towels and dried them. Could see
the base look newish (bronze/gold) like the unaffected part, and
the tips still look pointy.
Jeff Schwarz restatement is quite correct. Oil drained into the sump
and we had added more, and that probably caused the overfill. In
the future, rather than just adding to the top of the battle on
cold, best to measure out the 8quarts (7.57L) or as JS mentioned
to check external tank level AFTER engine has run for few moments.
(next time in Chicago, will hv to swing by Crystal Lake!)
In any case, re-installed the cleaned plugs.
Restarted, and just slight white smoke, and very slight thereafter
(total about 30seconds). This was about 10:30pm in the evening
(and as Crafty has seen the premises), didn't wanna wake neighbors.
But it seemed to have surely improved the situation. Will need
to run it longer in the day.
- I'll post beforecleaning and aftercleaning pictures of the spark plug.
- will check coolant for oilyness
- continue to add engine oil (as running on measured 6L at the moment)
Suggestions for future. Dry sump to have oil level sensor (like in
standard corvette). Ultima's external oil tank to have dipstick
as well temp sensor.
I did have a word with Dave at the factory.
Still haven't gotten a compression gauge yet but did the following.
Took all 8 plugs out.
Cranked the engine about 3 x 10 seconds (can see the pistons
going up and down through the sparkplug hole, as well as
feel the air being blown/pushed out).
External oil tank toptube return to engine / intake manifold -
I manually blew into it (just incase any unlikely blockage)
Fyi, engine had only needed to be turned on to get the white smoke.
And we have been running it inside, haven't done a 15-20 constant on,
nor an outside run yet.
Suntiger(Dom), yes they were black (oily/filmy ard the top 2-3 threads
and the spark plug tip and curve were black as well). I cleaned
the best I could using paper towels and dried them. Could see
the base look newish (bronze/gold) like the unaffected part, and
the tips still look pointy.
Jeff Schwarz restatement is quite correct. Oil drained into the sump
and we had added more, and that probably caused the overfill. In
the future, rather than just adding to the top of the battle on
cold, best to measure out the 8quarts (7.57L) or as JS mentioned
to check external tank level AFTER engine has run for few moments.
(next time in Chicago, will hv to swing by Crystal Lake!)
In any case, re-installed the cleaned plugs.
Restarted, and just slight white smoke, and very slight thereafter
(total about 30seconds). This was about 10:30pm in the evening
(and as Crafty has seen the premises), didn't wanna wake neighbors.
But it seemed to have surely improved the situation. Will need
to run it longer in the day.
- I'll post beforecleaning and aftercleaning pictures of the spark plug.
- will check coolant for oilyness
- continue to add engine oil (as running on measured 6L at the moment)
Suggestions for future. Dry sump to have oil level sensor (like in
standard corvette). Ultima's external oil tank to have dipstick
as well temp sensor.
Edited by DiscUltima on Wednesday 3rd September 01:22
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