Smoke/exhaust coming through vents/hood from CP-E downpipe at idle

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steefnap

Member
Hey all,

Just got my CP-E downpipe and CP-E exhaust installed in my Speed6. It has only been 3 days, and I have noticed occasional smoke (exhaust?) coming from under the hood, and coming through my cabin air vents.

I noticed when I picked up the stock parts from the mechanic, that one of the downpipe pieces was segmented and had some small springs on it, presumably to account for engine movement during acceleration. I did not root through the box that the CP-E gear came in, so I was wondering if the downpipe has this same feature? If not, does it mean that due to engine movement that the downpipe has come a little loose, and is now venting exhaust when it's not being forced out the back?

I am not the most mechanically-inclined, so I have to rely on my fellow speedheads and my local mechanics to tell me what might be the best course of action to take.
 
I have the same issue when it starts to smoke. I just chalked it up to the lack of multiple cats in the exhaust. But Im not sure, I do have to put the AC on max when im sitting so it doesnt suck the exhaust fumes in.
 
yes, you do have a exhaust leak, tighten up the downpipe some more. check and make sure your 02 sensor is in. but it is normal for mazdaspeed 6's to smoke due to the turbo. i called cpe when i put my buddies full tbe on and it wouldn't stop smoking, they told me it is 100% normal and the only way to fix it is to get a new turbo. so you pretty much have to deal with it, or go back to stock.

at least if you are sitting at a stop light and you see a mazdaspeed 3 or 6 smokin, you know its modded. (glare)
 
what the hell? I paid how much for this setup, and now I have to deal with a smoking car? Why would be turbo be to blame? It did not smoke before. I did not expect to have to spend even more money on a new turbo just so I would not have to deal with smoke. It is making me consider just ripping it out and putting stock back, and selling the downpipe/exhaust to someone who wants to deal with the smoke/noise.

~FRUSTRATED!!~
 
amp said:
sounds like you have an exhaust leak...
Click to expand...

I concur. My complete CP-E exhaust system has to this date never smoked. (knocks on wood, Ouch............Never ever knock your own groin, trust me) (boom08)
I believe yours just needs to be tightened up.
 
Once again the smoking is not caused by CP-E's DP / Exhaust system. I had it before I installed their system as well as other people having it on completely stock cars. As for replacing the turbo, if the dealer gives you a new one and the old one has no traces of leaked oil inside of it then the dealer has to eat the money, or so it was explained to me.

1badsrt, Im wondering if the "vibrations" of the exhaust are loosening the DP causing it to release smoke under the hood?
 
I will try tightening the DP to see if that helps. I suspect the vibrations or engine torque may loosen the DP from the motor, based on my previous observations of the stock downpipe (segmented w/ springs). Hopefully I don't have to retighten every so often, as that will be annoying.

If tightening doesn't work, you are suggesting that a visit to the dealer to inspect the turbo will be the next step? Will they not try to void the warranty? What can I arm myself with so that the dealer doesn't pull one over me? Is there a service bulletin that deals with the smoking turbo?

Thanks for the feedback so far people.
 
As far as I know there is no service bulletin but the if you speak to the techs they will probably tell you they have seen a lot for the same problems. They wont replace my turbo though so im not sure what the issue is. Once again they would legally have to prove that the DP caused the malfunction...correct me if im wrong but I think its pretty damn difficult for an aftermarket exhaust system to damage the components before it...

Mainly its probably dependant on the dealer, the tech that works on mine said they wouldnt have a problem with a CAI...at the same time when I had a 3 back in FL the service dept tried to tell me it would void everything lol which I knew wasnt true but interesting nonetheless
 
I have my car in to the mechanic who installed it, with instructions to tighten up the DP. So I will let you know how things turn out after that.
 
Mine started smoking again also so I drove it straight up there and left it running. Clouded up the whole service lane and everyone looking at it like wth. Needless to say the have the car again, and I am stuck in a Chevy Cobalt rental...man what a pos.
 
Tightening the DP did not help. My mechanic figures that the gasket between the exhaust manifold and the cat is to blame. (Part number 13-483D according to a diagram I have). The cost of the gasket is $85-ish, and since I am bringing it in to Mazda to have them look at it, I doubt they will cover it under warranty. However that will likely only fix the "exhaust in the passenger compartment" problem. It won't fix the overall smoke problem.

It seems to me that it doesn't really smoke if you baby it and ride nice. But if you just stomp on it a bit to get things really rolling, and then slow/stop, you really notice it right away.

So from what I understand from other posts about this smoking issue, it is due to the turbo leaking oil inside, and that oil is getting burned during combustion? Is there a way to prove it somehow? And if this is happening at the turbo, does that mean that the exhaust has nothing to do with it? All this stuff seems to be happening before it gets to the downpipe.

Another point of interest... something to think about, perhaps something for the CP-E guys to look at as well... with the moving about of the engine and dismantling of parts to get the downpipe in, is it possible that this work did some sort of damage to the turbo and that is why it is leaking oil? This problem seems to come up after people install the TBE. I am not pointing fingers, I am just coming to a possible logical conclusion given the information that I have from these forums.
 
steefnap said:
Tightening the DP did not help. My mechanic figures that the gasket between the exhaust manifold and the cat is to blame. (Part number 13-483D according to a diagram I have). The cost of the gasket is $85-ish, and since I am bringing it in to Mazda to have them look at it, I doubt they will cover it under warranty. However that will likely only fix the "exhaust in the passenger compartment" problem. It won't fix the overall smoke problem.

It seems to me that it doesn't really smoke if you baby it and ride nice. But if you just stomp on it a bit to get things really rolling, and then slow/stop, you really notice it right away.

So from what I understand from other posts about this smoking issue, it is due to the turbo leaking oil inside, and that oil is getting burned during combustion? Is there a way to prove it somehow? And if this is happening at the turbo, does that mean that the exhaust has nothing to do with it? All this stuff seems to be happening before it gets to the downpipe.

Another point of interest... something to think about, perhaps something for the CP-E guys to look at as well... with the moving about of the engine and dismantling of parts to get the downpipe in, is it possible that this work did some sort of damage to the turbo and that is why it is leaking oil? This problem seems to come up after people install the TBE. I am not pointing fingers, I am just coming to a possible logical conclusion given the information that I have from these forums.
Click to expand...


This issue is not coming up after the install of the DP, its just more noticeable without all the cats. I had the issue prior to the install with my old exhaust and some are having the issue with completely stock vehicles. So are they not doing anything about your smoking issue? They still have my car and are running more tests tomorrow. On other forums Ive read where one individual at least has had Mazda buy it back because they could not figure out what was wrong with it...others are just having their turbos replaced.
 
My car goes in tomorrow, so we will see what Mazda has to say about it then.

So if I tell them that I had some smoking going on BEFORE the install (a fib, but perhaps one way to motivate them not to blame the TBE?) that might get a better result from them? I don't like to lie, but I can just see them taking advantage of the whole "aftermarket = bad" scenario.
 
steefnap said:
My car goes in tomorrow, so we will see what Mazda has to say about it then.

So if I tell them that I had some smoking going on BEFORE the install (a fib, but perhaps one way to motivate them not to blame the TBE?) that might get a better result from them? I don't like to lie, but I can just see them taking advantage of the whole "aftermarket = bad" scenario.
Click to expand...


It shouldn't matter really...If they try to pull something I would ask them to explain it. How is something such as exhaust system going to cause problems with anything that comes before it. I wouldnt even tell them that because unless they have record of it you could "tell" them anything but it wont mean much if they're trying to be A**holes. But any service mechanic worth his salt would tell you the TBE is not the cause of the smoke.
 
steefnab, i went thru the same problems as you. I put the car back to stock, took it to the dealer and told them i see smoke at idle. They said that its natural for the car. I then told them that i read somewhere that the smoking is bad seals on the turbo. They still didnt fix it for me. I know how frustrating it is, especially when certain companies dont tell you what your getting into when you buy some parts even if its not the parts that cause the problem. You buy a $25K-$30K, nobody wants smoke coming out of the exhaust. I had the fire dept called on me twice. I finally just sold the downpipe and now im going with a turbo upgrade. I'd rather spend the money so that my car doesnt get laughed at when i go to meets, shows, and the track because clouds of smoke are coming out of the exhaust.
 
No way is it natural, a turbo should not be smoking. I have a custom 3" TBE and I don't smoke at all. I guess I can maybe see if you have no cats, but if you have a cat, you shouldn't smoke at all.
 
My CP-E came with the cat. Either way because I have an exhaust leak at the engine, smoke comes from under the hood as well as out the back. So before AND after the cat, there is smoke. Cat does nothing to eliminate the smoke.
 
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