Smoke coming out of flex pipe

Hello everyone,
have a 2004 aveo 1.6 and one day when I was driving it began to stall. I was able to make it to my apartment and then decided to check. Check engine came on. I opened the hood and smoke was coming out. I let it settle for close to a year and few months since I have another car and from what I found online was a possible head gasket problem. I check and there was smoke coming out of the tailpipe (white). The car was having problems running and was dying after starting so replaced the coil and also the spark plugs along with the wires. After that the engine would actually run okay but the smoke was still coming out. I ordered a head gasket kit and decided to change it. I spent the last week an a half changing the head gasket and just finished today. For the moment of the truth, the engine started with no problems and the check engine light was not on. However, two things are happening right now:

1) there is a knocking coming from the engine which increase if I press the gas pedal. The knocking appeared before I replaced the head gasket and thought that it was because of bad oil (read somewhere that old oil might create knocking). This is the sound of the knocking: https://youtu.be/AgL0kiy2TCw

The head engine was resurface and they also checked the valves. What exactly they did with the valves? they said that they checked the pressure and something else but the guy clearly had no idea (cashier). Would this be a bent valve? (hope not because it was a long week to bring everything apart to do that).

2) There is still smoke coming out of the "engine". However, there is no smoke coming out of the tailpipe but the flex pipe. I am now thinking that that was in the beginning the issue and did not have to replace the head gasket. However, there is no check engine light on now and the car does not stalls. It runs (idles, has not driven it since it first happened) good but there is the knocking and the smoke coming out of the flex pipe.

I really need help asap. I need to fix it and I am not sure what it could be. When I put the timing belt back the gears were align almost perfect (There were like 2 mm off) and the crankshaft and piston number 1 was at dead top center. I might guess that there is a bad timing and might be creating the knocking? From what I know the car never overheated (the car does not have a temp gauge to know). I am thinking that there might be a vacuum leak? I just can't figure out what is the knocking and the smoking. This car has 67000 miles on it. Almost forgot, I heard that I need to empty the fuel tank and get new gas in it. The tank is almost full and that is a lot of gas that needs to be thrown away but would this be a cause for the knocking? Any help will be appreciated.

So exactly when did the knocking start? If right after the spark plug swap, then perhaps you used plugs with the wrong heat range.

Hi avguy,

Thanks for replying. When the car started to have problems and started stalling and dying there was no knocking sound. after a year I decided that was time to fix it so I tried to turn it on and then the smoke was coming plus the knocking. I maybe started the engine two more times for 5 secs and then proceeded to replace the head gasket. Spark plugs are new and got them from autozone. Tomorrow I will see if I can drop the tank, empty it and get some new gas in it and see if that might be the issue.

I bet it's the valve cover gasket. Remove a spark plug and see if there is oil around it. If so replace the valve cover gasket.

Hi xinterxecty, checked the spark plugs and no oil at all. Tried to empty the fuel tank but I had too much gas so empty almost all the way to 1/4 and put a gallon of fresh gas plus Chevron additive but still knocking sounds still there. I have been reading and it says that if the knocking sound increases with acceleration then it could be a fuel mixture/combustion timing problem.

About the flex pipe smoking I think there is a leak of coolant/freon because when I checked underneath, the AC compressor had liquid all over. I have to lift the car really high to see.

I am more concerned about the knocking... any help will be great.

Knocking from the lower part of the engine would be really bad news, so you need to identify where the noise is coming from. Best way to find the noise is to use a mechanic's stethoscope, but you could try a piece of wood or hose first. The fan will come on after idling for a while, so watch out for your hands and fingers!!!

AFA the leak, dry and clean everything off completely (top and bottom), run it, and then take another look. It will hopefully be obvious at that point where the source of the liquid is coming from.

Update:

Thanks avguy, I have seen you help a lot on this forum so that is really nice man. The knocking comes from the top 100%. I did a compression test and it did 190 190 95 190. The compression on all of them is good. Something new that came when removing the spark plugs was that there was oil on the well (I believe that is the part that creates the spark). And I noticed that there was a tiny bit of oil on each of the pistons. I cleaned the pistons before putting the head gasket so that is how I can see the little bit of oil. I read that I might need to change the head gasket (maybe what xintersecty said before, I thought he meant just to unplug the wire and check for oil around the spark plug while still in). I have another head gasket and going to get new spark plugs. Read that they might let pass oil if failing. Any thoughts about what could be the oil going into the combustion chamber? Once again the check engine light has not come on.

Hi Johnlopez, it looks like you got a bad cylinder. If your compression test values are accurate the one with 95 lbs. of compression is bad. Can you perform a leak down test? That will clearly identify the issue. Bring the suspect cylinder to TDC, connect the guage to the spark plug hole and the other end to an air compressor. Pressurize and listen for the sound of air escaping. If you hear air escaping from the breather its a cylander/piston problem. If you hear it out the tail pipe - its an exhaust valve problem. If it is coming out the intake - its an intake valve problem. If it is bubbling out the radiator surge tank - its the head gasket. You can pick up a test kit for like 45 bucks at an auto parts store, some parts houses will even let you borrow one if you leave a deposit. I hope this helps you locate your problem.

Hello Bad_Elmo--> :eek: lol, I actually after seeing your post went ahead and re-did the test since the car was warm. all of them did max PSI of 199. I figure it would be 200 since I am not sure when that gauge was calibrated. I am still going to try to do the leak down test. I read about it but I have not a compressor or the tool. I will have to figure it out. I will check all the auto parts here.

As of the smoke, I think it stopped. It does not smoke anymore (visibly) but it still smells like electronics burning. I did see that right where the new thermostat connects to the hose that goes to the radiator was leaking so I made sure it was really tight and did not see any more the smoke. I am already home ( I have the car at my friends shop and worked on it all morning). I replaced spark plugs and did the same. The car runs good and check engine light is not on and it does not overheat. It barely got to 1/4 (temperature) since I just let it idle for a bit. I did moved it a little bit back and fort and did okay. Got this guy looked at it and he said that it is normal since I replaced the head gasket but to be honest doubt that guy knew about it. I felt I knew more about fixing the car than him. Anyways. It idles it does not hesitate but the knocking still there.

does any body know how to find out if the timing is off? For the aveo the two cram gears had to be align with the crankshaft and piston 1 TDC. When I move the crams to be align they were off by 2-3 mm and I moved one a little bit to make it perfect but it would not stay it would move. I just adjust the other gear along with the crankshaft and put the timing belt. When I spin the crankshaft twice they did align but as I said they were off by 2 mm give or take. Would be this the problem? This job took me a week and a half so to go back to that point is something I am avoiding but if that is the problem I will go back and re do it.

One more thing is that I read about checking the EGR since there might be a air mixture problem. What I did was that when the car was idling I disconnected the plug and the car did not show any difference. It ran the same with the same sound. I know that when you check a bad coil or wire you do that and you can tell when it is good or bad. Could that be apply to this part? should it have made a difference? it looks rusty and beat up but I already spending too much money on this car.

Thanks for the help and time reading this long posts...:confused:

Quote:

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Originally Posted by johnlopez

does any body know how to find out if the timing is off? For the aveo the two cram gears had to be align with the crankshaft and piston 1 TDC. When I move the crams to be align they were off by 2-3 mm and I moved one a little bit to make it perfect but it would not stay it would move. I just adjust the other gear along with the crankshaft and put the timing belt. When I spin the crankshaft twice they did align but as I said they were off by 2 mm give or take. Would be this the problem? This job took me a week and a half so to go back to that point is something I am avoiding but if that is the problem I will go back and re do it.

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More likely your timing was good. Once you put the belts on and align everything the timing looks slightly off as the intake cam if forcing against the slack in the belt. Once the belt tightens, the marks align. This picture was taken before the water pump was tighten down. And beside if your timing was off your compression numbers would be bad/combined with that special crunchy sound of bent valves.
Attachment 10925

I wonder if the knocking is a bad lifter?

Hi xintersecty, bad what filter? air? oil?

Hi, that is exactly how mine was. I asked the guy who came and looked at it and said that if the time was off then it would not start or would barely running.

The lifter is the round part that goes from from the engine cam to the valve.
Attachment 10926

This is the sound it makes.
https://www.youtube.com/watch?v=ikmJ4-RcGDw

Hi, Sorry I misread filter :laughing3:. That might be. The sounds is very similar. would you listen to mind and tell me what you think? I am super frustrated already and for me everything is wrong with it. https://www.youtube.com/watch?v=AgL0...ature=youtu.be.

But for that I would have to take everything apart again. Would this then make it run better? runs good but sound coming out of exhaust is not the best.

After watching your video, I would say try these easy fixes before you take it apart

Quote:

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Rislone Engine Treatment is a lubricating oil that cleans and protects. It penetrates the areas of the engine where deposits form, such as the valve seats, piston rings and bearings. The treatment works against the deposits and allows them to be trapped in the oil filter. Engine deposits work negatively on parts, causing altered tolerances, stuck parts and noisy lifters.
Liqui-Moly Tappet Stop Noise works in a similar way as an oil additive. It works for all types of engines, including diesel. It also works with any type of engine oil. It cleans engine parts, including worn lifters, and dampens the noise these parts can make.

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Stole that from the internets with the usual disclaimers. You can replace a lifter without taking everything apart if you know which one. Just a matter of removing the valve cover. Loosen your timing belt, remove the cam, replace the lifter and your done!

I am going to buy that right now and tomorrow us it. The dilemma would be how to find out which one it is. if I turn the crankshaft manually with the valve gasket cover off would I be able to hear the clicking? do you know if this is even safe to do? BTW thanks for the replies.

IMO the noise on your video is something that could be caused by a number of things. Whenever I'm dealing with a noise like this that hasn't been positively identified, I remove the serpentine belt and run the engine for a short time, in order to find out if the noise is still there or not. A bad (A/C, alternator, ...) pulley bearing is one of the possibilities, and your Aveo being off the road for that long would also allow rust to settle into one (or more) of the parts in the belt loop. This quick and easy test will either eliminate all of the parts in the belt loop, or will confirm that the noise is coming from one of those components.

Hi avguy, I thought the same and went ahead and remove the serpentine belt. no change at all. :S

I am going to clean tomorrow the EGR valve and also the gasket since I have an extra one.

Well, I agree with xintersecty. It sounds like valve tap. bear with me for a moment I'm old... school yea, old skool. back in the day before hydraulic lifters we had hard lifters, push rods, and tappets. we had to set valve lash with feeler gauges every 5000 - 10,000 miles. let's say once or twice a year depending on your driving habits. Now we have cam followers that work off pressurized oil from the oil pump. no need to manually adjust them, but if they fail/collapse, the cam lobe slams into the follower every time it comes around and makes that tapping/knocking sound emanating from the top of the motor.

Hi guys,

Okay about to head over the shop. Got the Risolne treatment. I got the compressor already there and still looking for the compression tester for the leak down test. Got me some carburetor cleaner to clean EGR and will replace its gasket. I am going to replace the coil and wires (I have extra ones went to junk yard and got some to see if mine are bad). hopefully I find the problem. Thanks

Update:

Got here. Went and grab a fuel compression tester and did the test it was never below 30 or higher than 60. Saw a video saying those are the red zones. it did if i remember right 45 or so. turn on the engine and it was holding the same. When I was about to pour the Risolne I noticed that the bottom part of the cap had a milky ****! thought it was coolant and was about to shoot my self but read and it looks like there is moisture in the engine which I can agree since the EGR had some drops of water in it. I need to get rid off the moisture any suggestions ?

Have not done the Leaking down test yet but where can I start if I want to see if there is any vacuum/ air leak? When I turn off the engine it sounds like if there is air exiting somehwere idk. :S

Well back at home. another day another failure.:mad: :(changed coil and wires and nothing changed. Did a leakdown test but I must say that it is kind of hard to find out if there is a leak. all the pistons showed to be with no leak but only when I brought one by one to top dead center. What I mean by this is that I would bring piston 1 to DTC and there will be no leak but when I go and check number 4 there will be a leak unless I turn the crankshaft a little bit and then there will be no leak. The only way that I was able to check for a leak was through the air intake throttle. The car has no radiator cap and I do not know how to check for leaks on the exhaust side. The Risolne didn't really help. open for any suggestions!!

Interesting to follow this adventure! It's difficult to follow what you're trying to do since you don't really know what you're doing. But there's no doubt you're learning as you go. We readers won't know what you're doing when you "grab a fuel compression tester" for example since there is no such tool as a "fuel compression tester". Most of what you're checking has no relation to any knocking sound, but it's useful for you to learn how to take things apart and put them back together again. If you can (and the car is driveable) take it to an experienced mechanic and ask. You'll get an experienced answer right away without having to disassemble everything.

Quote:

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Originally Posted by JJJoseph

Interesting to follow this adventure! It's difficult to follow what you're trying to do since you don't really know what you're doing. But there's no doubt you're learning as you go. We readers won't know what you're doing when you "grab a fuel compression tester" for example since there is no such tool as a "fuel compression tester". Most of what you're checking has no relation to any knocking sound, but it's useful for you to learn how to take things apart and put them back together again. If you can (and the car is driveable) take it to an experienced mechanic and ask. You'll get an experienced answer right away without having to disassemble everything.

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Well man first, I am glad you were able to reply. I would have never ever thought about taking the car to a mechanic. Your IQ must be 120 or higher. I feel lucky I got your very helpful input about what I could do.

Sh!t If I can drive the car I would have done it already in the first place. No, I do not know the correct term for that tool. knowing the right name or not wouldn't make any difference at all. Fuel Pressure testing Kit. Big difference. Doesn't do sh!t for me. No, I am not a mechanic If I was I wouldn't post things here to get help. I have worked on cars before replacing parts but never had this problem. You sound like you know all this. Then, why don't you tell me what is the problem then? sound like you are an expert. Why don't help, which is the idea of this forum, instead of talking sh!t? I checked the fuel pressure to confirm that all fuel injectors were getting fuel and to make sure that injectors number 1 and 2, which are at the end of the fuel line, were sending enough gas. This would create a lower combustion and might create the noise.

Furthermore, the idea about the forum is to help so you input is useless. People come here for help because they are not expert and/or want to learn and replace the part themselves. Go post negative sh!t somewhere else. Actually, typing more is just not worth it for me since it is for someone like you. so to sum it up Fu<k 0FF.

In JJJoseph's defense, it is hard to decipher what someone is talking about when proper names of tools are not used, getting mad and aiming profanity at people just alienates people and makes it so they don't want to help somebody... we all come to this forum for help with problems not to get pissed on.