WilliamMeyer11

Hello, I'm looking into buying an 08 to early 09 Cobalt SS/TS. I was reading that the LNF has an issue with the block cracking.... I also read that its mainly an issue for these years...
Anyway, it seemed like if the motor did not fail around 40k miles, it safe to assume its probably a motor that was not affected by this. Is this true? has anyone had this happen around 100k or farther.
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sixgear

120k

Snail_SS

iTrader: (3)

Its hard to tell but some have experience the failure at highe milage jus like above, a new block isn't that expensive tho, but would see sick to have to buy one

exninja

iTrader: (1)

72k

Slowbalt2000

iTrader: (1)

Ive never had it happen to me but it seems most of them happen from 40-100k miles.

exninja

iTrader: (1)

I think one issue is if it happened early you may not have heard about it because it got fixed under warranty and the owner had no reason to make a big deal about it.

tomj77

iTrader: (2)

If u have an 09 with a stock lnf engine that hasn't been replaced with ldk then yes, porus block issue doesn't go away with time if u still got the motor thats known for it

63 Nova SS

iTrader: (3)

Advice- you are looking at buying an inexpensive performance car that likely along the way had at least 1 owner who ran it hard. With 100k miles on it, I would not buy it without having money left over for a short block or used trans. Unless you know the prior owners well. Cobalts aren’t expensive to fix but you have to have the money to do it going in. Anything that’s got that many miles will have issues sooner than later.

WilliamMeyer11

thanks for the heads up. is it more of an issue with tuned cobalts then? also, what are the trans like.

I guess to some everything up, what kind of reliability can you see around 300hp with good maintenance?

and I'm all too familiar with maintenance on old cars. Ive got an 05 Jetta GLI 1.8t tuned on 20psi (Pray for my stock K03 XD). but its only at like 200whp and the motor is okay BUT, the suspension and basically everything else isn't. I don't think the previous owner did regular maintenance and now I'm paying for it.

Anyway, I know you few can't solely tell me if the car I buy will be reliable, I am just wanting to see what other people have dealt with and what to avoid.


TLDR: what your experience with the trans been? is the porous block mainly an issue on tuned cars? are these fairly reliable at 300hp?

exninja

iTrader: (1)

It is unaffected by power output. My opinion is it has more to do with heat cycles.

63 Nova SS

iTrader: (3)

Personally I haven’t had issues with the trans or block in my 09, but it’s only got 42,000 miles. That said I have a spare trans, and forged rods and Pistons ready to throw in a ldk motor, than I plan on getting soon, to be ready.
The pourus block happened even on stock motors, as its really just a problem of how gm casted the block. I baby my car most all the time, that said, it’s probably seen 25-30 drag strip passes. It’s setting at about 370whp now, and while it’s been reliable I also know that at any time I can get seepage into the cylinders.
The transmissions suffer from an alignment issue internally, and lack of support for especially 3rd gear, causing it to only partially engage, break, and ruin the trans. 300whp on the trans isn’t gonna kill it as long as you don’t have wheel hop, and put it though shock loading every day. You can get suspension parts to eliminate the hop, and as long as you don’t drive it like an asshat the trans will be fine, especially on factory tune. Quick spooling big turbos can kill one pretty quick.

WilliamMeyer11

I see. Last night I told myself I should probably look at other cars but nothing is getting exciting me quite like this did. I want to do the GM stg1 tune, exhaust and coilovers and daily drive it. I have hear that the early 08s may not have this issue. I might look for one of those or a 2010 although the 2 doors seem few and far between though.

Maybe I'll go drive an SC model but I think at that point I would rather pick up a mazdaspeed3 or 2.0T golf.

thanks for helping me with this.

exninja

iTrader: (1)

The two doors are a LOT more common than four doors, and four door TC only existed in 2009.

I think you'll be disappointed if you get an MS3 or turbo golf, even compared to the supercharged balt.

WilliamMeyer11

woah, your thinking a SC cobalt would compete well with a MS3? My roommate has one that was door to door with a new coyote 5.0 and that was before a new Catless DP and more aggressive tune.... I know the 2.0T Golf wouldnt be too crazy.
Huh, maybe ill look into the SC cobalt more

63 Nova SS

iTrader: (3)

Guessing the mustang owner didn’t know what he was doing. They can be pretty quick with a decent driver. I’ve raced 3 different fbo speed 3’s at the strip and none have been real close.
If you get a Cobalt save your money and don’t get coils or exhaust, just get a different downpipe. Factory exhaust won’t hold you back at 300hp. I drove a speed 3 and liked the interior but not much else.

exninja

iTrader: (1)

Stock for stock the MS3 would likely pull the SC pretty hard, but word on the street is they're pretty much maxed out. You can get a new pulley, injectors, and tune for pretty cheap on the SC balt; and it comes with supercharger whine. The golf is expensive to mod, and even just to maintain. Even if you include a new engine, it's hard to beat the value of the TC balt.

ECaulk

iTrader: (6)

Iirc MS3's go through transmissions faster than a zfr cobalt.

Honestly the porous block issue is minimal, if you keep an eye on your fluids and at the first sign get a block sealer you can get another year to two before you need to replace the engine.

califcarm

I bought my 2009 with 132K miles on it. It was one owner though, who made long commutes and did not drive it hard, ha dall service records, etc..... I had GMS1 on it when I got it, otherwise stock.

I too looked at several other cars as I came from a high 11 second platform and wanted some good straight line speed that could also handle reasonably well without breaking the bank.

The TC sedan was perfect. Has 165K miles now and some small stuff like sensors have been replaced, and just the IC and upper charge pipe (both factory plastic units exploded after I went to 23-24 psi on self tuned HPT).

Can't really beat the value, as when tuned these run very strong for the money invested on just a tune. (stomped a tuned MS3, easily walked away from a tuned BMW 335i, and even edged out an Audi R8 with an exhaust). All with a stock turbo balt. They can trap up to 115mph with a tune and just a hand full of bolt ons.

The GMS1 tune you mention is not bad, but night and day better to get HP tuned IMHO.

Just need to find a clean example that has not been abused.

umrdyldo

iTrader: (1)

I remember one member saying they had decent luck putting a good block sealer in their coolant and running it for awhile, then drain and refill the system.

But that's not necessarily going to fix your issue if the leak is bigger.

Good Luck.

ECaulk

iTrader: (6)

That's why I said checking fluids regularly so you catch it at the first indication of a leak

umrdyldo

iTrader: (1)

If the coolant overflow is properly filled, the low coolant indicator should come on pretty quick to let you know if there is a leak. Don't even need to open the hood to know if it's low.

ECaulk

iTrader: (6)

I wasn't sure when the light kicks on for these cars.

umrdyldo

iTrader: (1)

It just shows up on the DIC, if it's slightly low it will set off going up or downhill. It's fairly fast.

soundjunky

iTrader: (4)

I'll throw my two cents worth in on the original question;

It is my opinion that 99.9% of the acclaimed porous block issues popping up more than (oh let's say) three years after it has been put into service are complete BS.

I know a gal in my state who was told she had a porous block which was the cause of here engine failure...
The only problem is that her car was fine prior to getting tuned, and this happened in 2016 ~ and her car was a 2009(iirc);
I believe that in her case (and I suspect many others are the same) the tuner/tune is wholly responsible for the problem;
In her case the tuner and other locals blamed her block - so she took them at their word.. .not noticing how the locals think that this tuner can do no wrong.
I felt bad for her but when I found out about this it was well past the point of no return, as she had totally parted the car out... and unfortunately was still making payments on it.

The porous block issue was about a specific batch of engine blocks which were not cast properly;
I believe there is a thread here which has the TSB clearly spelling out a manufacture window of cars which may have recieved those engines.
As I have understood it, the problem would surely show itself within the powertrain warranty period - unless the car was bought, and parked...

The Cobalt SS(TC) is a great little car;
I like some of the others who have replied here, am an original owner.

The Cobalt SS(SC) is also a great car, but I personally was only motivated to look into buying after the TC came out;
As mentioned above the SC can make great power - I believe that the GMS3 was rated at 300hp in 100 octane gas mode... otherwise the "street" version (it was never officially released for street use; it disabled A/C, and came with an "offroad use only" sticker) had roughly the same horsepower as a stock SS/TC.

It is my opinion that the tansmission "issues" are really only prevalent under one of two (or both) situations;
1) aftermarket tune with little to no attention paid regaurding a gradual boost ramp
2) an aggressively tuned car which may have a decent boost ramp, but the owner has been jumping on it in 5th gear.

As it has been suggested, I would definately look for a car that has been well cared for - often the ones which have few to no modifications are the best ones to start off with, unless you really know (or can trust) the past owner of a modified car.

CudaJoe

iTrader: (1)

original owner here. mines an 09 LNF 4 door. I havent had a porous block issue and still have the LNF motor. Im 200 miles shy of hitting 100,000 miles on the odometer. My cars been tuned since 46,000 miles. Spark plugs replaced around 60,000 miles, not because they were bad but because some people claim you should change them periodically when tuned. Plan to change them again around 120,000 miles. My stock motor, turbo, and trans all seem to be holding up fine. Im on the original clutch as well. I daily drive everyday, and I do a few fun pulls every now and then in the summer. Like once a week I will rack through 2nd, and 3rd gear to the redline.

My car hasnt had any mechanical issues, except for a faulty ignition tumbler that locked my key into the ignition and wouldnt let go. My suspension feels as good as the day I bought the car. I do get a knock sound under the car when traveling over gravel while turning the steering wheel. I believe its apart of the steering but it could be a bad CAB. Either way its quiet most times unless the road work being done. My cars 300+whp and 330+trq. I do not have an exact number but im on 24 psi tune now and the 20 psi tune I originally had was 300whp 330 trq. This tune is definately noticeably quicker.

TLDR: With the right owner, the car could be mint. Im also not sure if porous block will ever happen on my car because it hasnt yet.