Should I gamble $800 on timing chain replacement 2007 Cobalt 2.2 LS

[nonewcars]

I have a 2007 Cobalt LS that threw a check engine light a few days ago. The car displayed a service traction error and died. The car was able to start but can't go much faster than 40 mph. Took to chevy dealer and they determined the timing chain tensioner was in the lock position and the chain had lots of slack. Mind you the car would start and even idle okay. You can smell gas after you kill the car. So its around $1500 total with the work they have done already to get the chain installed and all put back together. The dealer warned me no guarantee there is not not valve damage. Another shop will do the same work for $800.

Some reading Ive been doing on these ecotec engines is even if the chain doesnt break, you could still have bent valves.

Is it worth the gamble to do the repair or are the odds against me here?

Would the car drive and idle fine if this were the case? Does the fact the car would try and die after 40 mph already mean I have major engine problems?

Please chime in as I need to make a decision in a couple of days

Thanks

[Tech II]

I am missing something here.....big difference between 800 and 1500.....exactly what have they done to the car to warrant 1500? Please don't tell me it's 700 in diagnostics!

I'm figuring 400 labor and 200 parts....good tech should diagnose in one hr.....even adding another hour, at 100/hr, is nowhere near 1500......

[nonewcars]

The dealer charged 35 for the computer diagnostic and then 380 to "tear it down" to see what was wrong. They have pulled the valve cover and timing cover. That's it. They want 1100 more to put new chain and parts back on but won't guarantee I don't have damage. My bad for going to dealer.

Anyways I don't have a good feeling on this since I have read in soo many places any timing chain slippage or breakage will result in engine damage. Why are cars made this way?

[Tech II]

You said it idled ok...that is a good sign that the valves are not bent....

[nonewcars]

Well that's the positive I tell myself. The car wanting to die past 40 mph is what has me wondering. Only way to really know is put the parts on and see what happens

[Tech II]

I know we are talking about a chain problem here, but could a secondary problem be a restricted exhaust?

By the way, did you ever hear a noise from the timing chain cover when you revved the engine?

[nonewcars]

The odb2 codes were p0016 and p0017. Timing chain is one of the causes. I don't think it's a restricted exhaust. The bottom line is until the chain and parts are installed I won't know. If I had a spare vehicle, I could diagnose this myself for a lot cheaper. As usual everything seems to be an emergency when you got 5 drivers in your family

[nonewcars]

Just realized I did not answer your question. The car has had a cold start rattle for a while. If I had addressed the issue sooner, probably would not be in this situation. Once the car would start the rattle subsided. Now after this last issue, when I gave the car gas you could hear the rattle clearly. So I imagine its gotten slowly worse over the last few months

[Tech II]

I worked for GM and there are good techs, and not so good techs, just like any shop....just a head's up to anyone going into any shop...ask the SM who his best engine/diagnostic guy is...if he says they are all good, repeat the question....then demand he works on your vehicle....one more thing, hate to say this, but it's true...if you are of the female persuation, have your boyfriend, husband, father, etc., go with you to do the talking....hate to say it, but females tend to get the short end of the stick.....


They should have heard the rattle on start up, and not wasted time on diagnosis....this problem kind of started on early 2000 Ecotec's...the problem back then was a restricted oil orifice, which did not allow the chain to get lubricated....the fix back then was replace the chain, tensioner, cam and crank sprockets, the orifice(larger opening), and if necessary, the guides.....

The rattle would progressively get worse, until the chain would break, and then you would have bent valves and other problems.....

In your case, at minimum, the chain and tensioner should be replaced, the rest inspected.....I'm sure there is a bulletin(TSB) out there for this problem....Just for ha-ha's, ask their S.M., if there was a tsb on this problem, by punching in the engine and codes set in a TSB search....also ask him to show you the labor op time for this job.....as I said before, there is diagnostic time, and part of the labor was used in taking the timing cover off.....this time should be subtracted from the labor op for the job......with that rattle present, there should have not been any more than 1 hour diagnostic's time.....their top engine/diagnostic guy should have picked this up......

[nonewcars]

Thanks Tech II. Ill keep you posted. Will hopefully know by Tuesday what the story is. Chevy guy said the engine had some sludge in it as well. Not sure why. We have kept the car serviced regularly ever 3K to 5K miles. I have the complete estimate if your interested and the parts they were going to order

[nonewcars]

Well looks like the gamble paid off. New timing chain kit, plugs, oil and filter plus labor $980. Compression is within specified limits and car appears to run fine. I'll drive it a few days to work before I give back to my daughter but hopefully bought a little more time for her. So the saga is replacing a timing chain was a TON of labor on this deal. The chevy dealer charged $430 for the diagnostic and the second place $980 for parts and labor. Total cost $1,410. This feels way over the top but at least the car is fixed.

[Tech II]

While the GM shop diagnosed this correctly, they charged too much in their diagnosis.....

My question is, did they put the car back together and you brought it to the other shop?

Or did they leave it apart, and you had it towed to another shop?

Final cost was within $100 of each other....

[GMCustomerService]

nonewcars,

I am glad to hear that your are satisfied with your repair. I am interested in the $430 diagnosis fee. Was the cost per hour?

Erica Tiffany
GM Customer Care

[GMCustomerService]

nonewcars,

I am glad to hear that your are satisfied with your repair. I am interested in the $430 diagnosis fee. Was the cost per hour?

Erica Tiffany
GM Customer Care

[nonewcars]

Originally Posted by Tech II

While the GM shop diagnosed this correctly, they charged too much in their diagnosis.....

My question is, did they put the car back together and you brought it to the other shop?

Or did they leave it apart, and you had it towed to another shop?

Final cost was within $100 of each other....

The dealer did not put it back together. The way they explained the quote to do the repair was 1300 in addition to the 430 diagnosis. It is possible I misunderstood.

If I had them put it back together, it would have been additional labor. I had to pay a $65 towing fee to get it to the other shop