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Discussion Starter #1
I own a 2007 Cobalt LS. I was attempting to change the plugs for the 100k check up (company car lots of travel). Plug #1 came out just fine. Plug #2 was seized. Plug #3 was fine and Plug #4 would not budge. I ended up breaking plug #2 (dam). I used#5 easy out screw to attempt to take out the broken plug. I could not believe that the torque broke the ratchet and the extension drive. This is after I let the plug soak in WD 40.
Last year I had to replace the radiator after a chunk of ice went through it. The motor over heated, but I was not sure for how long it ran HOT. The car got towed to a dealer and a new radiator was installed. The shop guys said everything else was fine. Now I am wondering if the Head is warped or the plug is “welded” into the head threads. I can take the head off and attempt to remove the ceased plugs but am wondering if it is worth the effort.
My questions are should I get a new Head and just replace the old one. Is there a way to tell if the head is warped in that area? (All the seals are good and therein e is no leakage). If the Head is salvageable what would be recommended to get the ceased plugs out?


Thank in advance
Scott in Vermont
 

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To be honest, I would replace the entire head, if its warped its a whole lot of trouble, and forcing of seized plugs could cause damage to the threads, If you can change it your self then so do, it will give you a chance to look at the inside of your engine and clean up a little. You should be able to find a used head for your engine pretty cheap, maybe about $200. The L61 engine is used in many models and should be easy to find. If you were to re use your one, it would cost about $100 to re-surface it then who knows how much to remove seized plugs or if you even can without damaging the thread on the head.
 

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Thank You RequestISO

Thanks for the advise. The least expensive Head I have found was $275. My next question is "how much of the engine do you have to tear down to remove and replace the Head. I know I will need to buy new bolts, and gaskets. When looking at the price of a "torque Angle tool " I about croked! Is 22 ft pounds good enough? If you have a site that would expidite this repair I would be most thankful.

Scott
 

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Torque angle tool? You should be able to use a torque wrench and be good, or does it call for an angle after torquing to spec?

The hardest part about replacing the head will be getting the timing back right, but if you're careful, it will be just fine. The intake manifold will need to be removed (along with most of the parts up to it), and the exhaust manifold will need to be unbolted from the head.

Let me print out what I see in the chilton manual.
 

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Here are the two files from the Chilton manual
 

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Thanks MP81

---------- Post added at 11:55 AM ---------- Previous post was at 11:26 AM ----------

MP81 about the torque angle. Yes it calls for a 155 degree angle (what ever that means), the tool is over $500. This does not show up in the Chilton book. So I guess it is not needed just 26 foot punnds.
 

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MP81 Thanks again:
I think I may be confusing everyone. What I was refering to as the "head cover", is really the COVER. Engine Valve Rocker & Camshaft. This looks like the part I need to replace. The spark plugs and Coil wires are on the back side of the cover (standing infront of the bumper looking at the engine. The cost is $96 give or take and a gasket kit of aprox $36. So the whole fix should be in the ballpark of $132. No need for the "angle" tool. After looking at the whole engine specs I thought that draining the coolent was a bit much for this fix. Sorry that the names of items like "valve covers" get so complecated these days.
So am I correct in thinking all I need to change is this "Cover, Engine Valve Rocker & Camshaft, and the gasket?

STJScott
 

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You're talking about this, right?



That's the valve cover.

The spark plugs thread into the cylinder head.
 

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I believe the valvecover can be removed without taking the plugs out. Just the coils come off.
 
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