Po301 and ticking noise

Asked by Nov 04, 2018 at 07:45 AM about the 2007 Chevrolet Cobalt LT Coupe FWD

Question type: Maintenance & Repair

07 cobalt 2.2  suddenly died, was driving fine up to
that point. Battery was replaced along with
alternator a few months before. Changed plugs
finally started with horrible chain slap noise. Only
code was po301 and po171. Replaced timing chain
and components.  Replaced crankshaft tensioner,  
crankshaft chain looked fine. Note: timing chain
was slightly loose but not broken. Then had no
start no crank, found starter was gone replaced ed
starter, starts fine. Makes slight ticking noise, now
code po301 back again and really low on power.
Doing a compression check today but any other

3 Answers


Compression test will likely tell you #1 cylinder is down on compression. This may mean that one of the valves is bent. Just a guess though.

1 people found this helpful.

I did compression test, cyl 1 is 120, the rest is all 150. I continued to hear for tapping ticking noise and I definitely hear it under valve cover. Took it for a drive, no cel on, drove fine except for a little noise. This morning its rough and shaky. Could this be sticking valve, bent valve? Would replacing head cure problem?


If possible have a qualified mechanic evaluate it. It could even be a camshaft / valve lash issue. Pretty hard to figure out sitting behind this monitor.

Your Answer:


Looking for a Used Cobalt in your area?

CarGurus has 157 nationwide Cobalt listings starting at $4,500.

Postal Code:

Chevrolet Cobalt Experts

  • #1
  • #2
    John Carson
  • #3
View All

Find great deals from top-rated dealers


Related Models For Sale

Used Chevrolet Malibu
45 Great Deals out of 2,304 listings starting at $2,999
Used Honda Civic
189 Great Deals out of 5,890 listings starting at $1,495
Used Chevrolet Impala
55 Great Deals out of 874 listings starting at $1,995
Used Ford Mustang
70 Great Deals out of 1,839 listings starting at $4,700
Used Chevrolet Corvette
28 Great Deals out of 701 listings starting at $4,995
Used Ford Focus
88 Great Deals out of 2,079 listings starting at $1,970
Used Dodge Charger
40 Great Deals out of 907 listings starting at $3,944
Used Chevrolet Silverado 1500
134 Great Deals out of 12,518 listings starting at $3,995
Used Honda Accord
41 Great Deals out of 1,984 listings starting at $2,500
Used Ford Fusion
30 Great Deals out of 1,510 listings starting at $3,000
Used Toyota Corolla
191 Great Deals out of 6,917 listings starting at $995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.