Hey guys,

My 08 TC has about 32,000 miles on it and is completely stock. I have been commuting in it since the day I bought it. I drive about 70 miles a day, so it's not a huge commute, but it's all freeway miles. About two weeks ago, I noticed the car was running rough at idle. I figured it was bad gas or something, but it has not stopped. I have tried different Chevron/76 gas stations with no resolve. While pulling up to work yesterday, I heard a knocking sound. I drove the car directly to my Father's house and asked him to listen to it. He told me that it is likely a valve (I can't remember exactly what he said). The car is still performing well, although I never really get on it too hard. He said to drive it until it breaks, but I am a little nervous about doing so. The dealer I called said that since there is no CEL, there is not much they can do until the car gives us a CEL.

About three moths ago, the vacuum line the runs from the intake manifold to the intake (just after MAF) broke off. I don't know how long it was off before I noticed, but I didn't get it fixed for a few weeks. They had to order in the part which was on back order. Is it possible that it may have something to do with my car running rough?

Thanks a lot guys....

 

Some people have had their lifters shatter and fail; if it's knocking at the head and it's consistent with the engine idle it may be on its way out. Your dealership sounds to be full of **** btw. If I took my car into my dealer with an audible knock they would inspect it under warranty as required. No CEL doesn't mean there isn't a problem, the motor should not be knocking, they're just being asshats.

 

If it's running rough on idle then it may be a front 02 sensor. Have you noticed a difference in gas mileage? If the front 02 sensor goes, then it will idle funky and return poor gas mileage results.

 

Is this the one you broke?



If so, I just broke that one too Sunday night. I'm getting the AEM coupler to replace it. Should be here today and I'll put it on tonight.
I tried to patch mine up a bit for the time being but it's doing the same thing as yours. (minus the valve noise) When I start it up it really 'hunts' for a stable idle. While driving it's not too bad. Seems to drive ok.
All of that is because air is leaking in after the MAF sensor. Then the primary O2 sensor sees a slightly lean condition. So basically the O2 is telling the ECU one thing and the MAF the opposite.
As for the ticking... I guess you'll just have to wait until it breaks or call some other dealers if you have others near you. If possible, see if you can get a good video of it. There's some good people on this board and maybe someone can better help you that way. I didn't really want to spend money to fix mine but I'm past 36K miles and I don't think that intake piece is under powertrain warranty. I drive about a 70 mile round-trip highway commute to work also.

Good luck man!

 

It is likely an oil starved cam phaser if it is noisy mostly on startup but quiet otherwise. OP get that intake leak fixed. Warranty is your friend in this case. Change your oil if your oil life meter is below 80% and see if that helps any.

 

Hey Zander.. Just so you know, pretty much anything associated with your motor and tranny is covered until 100k, including that breather hose. You should just bring the car to the dealer to be fixed and nevermind the AEM coupler

 

That is why you have a 5yr/100,000 warranty.

 

I changed the oil three weeks ago, so I only have about 1500 miles on it. I'm using AMSOil and it seems to do very well in the car. I will be taking the car the a different dealer in my area. I am hoping that having the vacuum line disconnected did not do damage by causing it to run lean. Is it worth pulling out the spark plugs before I take it in since I won't be doing so for another week? If so, what am I looking for? Thank you for all of your advice, I really appreciate it.

 

Your car is dead stock and under warranty , I wouldnt touch a thing on it . It just gives a dealer legit leverage to say you caused something . I would just take the car to the dealer and let them figure it out . If your dealer is unwilling or unable to get the problem solved , get the regional chevy service rep involed .

 

I just brought my car to a dealer and they said only internal engine parts are covered. So that is not covered.

 

I would very politely tell the service rep to eat a dick and call the regional chevy rep right then... Like the guys above have said that is part of powertrain. The service writer was just trying to avoid a warranty service claim cuz he doesn't make any money on that.

The PCV (its a crank case breather) always breaks off of the intake side. It's a known problem in the car. The engine would likely throw P0101 which is a MAF code before the car damaged itself. Try to post up a video of the knocking so we can try and hear it. I know the engine is noisy but just try for us.

 

I asked him if that was under warranty, and he said it's not part of the engine. I said I don't understand how that isn't a part of the engine. He had a picture and pointed at the engine and said that's the engine, this is not. However, on the Chevy website it does say it covers the turbocharger, so I'm not sure about all of it.

 

**** dealers and they retarded way of thinking, the dealer we bought the wife's car from does the same thing.

Take the car in cause the transmission is acting up.

"uh yea, we drove it around the block, plugged the scanner in it, and couldnt find anything so we let it sit for 6 hours before calling you 10 minutes before we close forcing you to take it home"

 

Its most likely running lean where your breathed hose is broke off. That could be causing a knock/valvetrain noise especially if it is more noticeable under load.

Breather* damn phone

 

maybe a lash adjuster?

 

Powertrain warranty changes from year to year and vehicle to vehicle.
Many GM vehicle powertrain warranties will cover ECM, HUBS, AXLES, TRANSMISSION, PISTONS.... etc
Clutch usually is not warranty unless a defect was the cause.
subject to change at any time without notice.

as for the engine noise, take it to a dealer. don't call them, go to the dealership, get the service advisor to come out and listen to the noise so he knows what to write on the work order, even have the tech come out and listen. Anything internal to the engine is PT warranty.

 

Try seafoaming

 

Call up a regional service rep at GM. Tell them the problem, which dealer you are having the problem with, and which adviser you are having the problem with. Honestly I have absolutely had it with GM. The balt will be my last GM car, not because it has been a piece of junk or anything cuz Melissa has been good to me so far, because GM as a company has their heads up each others rectums. And stuff like this is an example. Honestly, I would leave it till there was a warranty claim cuz the motor blew because of that stupid hose and make them replace the motor cuz they wouldn't replace the $50 intake tube. F* you GM, you have taken enough of our money in the bailout and now you won't replace this dude's intake tube.

 

^Hey, the problem is that GM can't make the dealers do anything. They are independently owned and protected by franchise laws. So "GM" has very little to do with it. They can pressure the dealer if they become aware of your situation, but dealers are not GM-owned.

 

They should replace that under warranty. One dealership told me that it was a "wear item", LOL. It's funny after they replaced my shift assembly (under warranty) my PCV hose connection on intake had magically snapped when I got it back. They replaced it the first time held up until after my next oil change (through same dealership). Opened hood 2 days later snapped again, replaced it myself bought it off of someone on this site. (perfect condition) After another oil change it was snapped again. Now I've only taken my intake off twice since I have owned the car. Air filter change and checking Bypass valve diaphram for tears. They replaced it for a second time, each time the break was different, one seemed pushed while other break seemed like it was pulled. Yes I am on my 4th intake tube! If I go through another I'm purchasing the ZZP intake tube and calling it a day.

I'm having the same rough idle too, I've changed my plugs and seafoam at around every 10k miles, & new air filter. My gas mileage has decreased but thought it may due to 40k miles and a little carbon build up. I'll give the front o2 sensor a shot, how much are they roughly?

 

Wow something isnt right with if you have broke 3 intake tubes...WTF lol

 

Yea, lol. He has his intake tube positioned wrong or something.

 

There's basically one position for it to fit. I explained to the service manager how to take it off, and he just agreed. I've had all warranty work done at the same dealership and nearly everytime it took way longer to complete (compared to TSB estimated time) due to lack of knowledge or something else. This dealer *not mentioning name* had my car for a week to replace the shifter assembly and couldn't give me a rental, luckily I was able to borrow my wife's car for that period. 3 different part orders for the assembly, how is that possible?

If you read the posts above the break points were different on each occassion. Guarantee it was a mechanic man handling the sh*t out of it, to get my car out of the shop (time is money), seems like they're always short handed everytime I go in. The other close dealership I went to told me to take it back to the original dealership as it is a "wear item".

Op, tell the dealership it was due to engine vibration or some other variable that would put it out of your hands. You could escalate it or just replace it, I payed around 50$ for mine.

 

It's just very easy to break. I broke it while i was removing the intake tube from the turbo. It wasn't a big deal though cuz I was putting on a new intake but it really was just a little bump.

The dealer will do whatever GM says. If he calls the regional rep and the rep calls the dealer and explains to them it is a warranty item then the dealer's hands are tied, they have to fix it based on bargaining agreements. There are laws that protect consumers as well.

But in all honesty, F*ck the dealership and toss on an aftermarket intake and be done with it.

 

[QUOTE=RyRidesMotox;6268988]It's just very easy to break. I broke it while i was removing the intake tube from the turbo. It wasn't a big deal though cuz I was putting on a new intake but it really was just a little bump.


I had mine broke by the dealer and they told me it wasnt them that i must have done it. Then I bought all the treadstone parts and went back to the dealer to have the other work done and told them they break another part the replacing a more expensive one. Took 2 days to change the hpfp gaskets and valve cover gasket