Cobalt Tom
Platinum Member
I did not originally write this:
NOTE: I WROTE THIS UP FOR ECOTEC CAVALIERS but seeing as the engines are all but identical this will work on cobalts, they have only made very small minor changes.
Anyways, my original write up....
"There is allot of info going around about cam installs on an ecotec so I wrote up a step by step from beginning to end. There is a faster way to do a cam install then this but its not worth the risk, a couple people have had the valves hit pistons and I think everyone has messed up the cam timing and had to redo it. If you do it this way your timing will be right and there will be no valve to piston contact. I suggest you read this all the through beginning to end before attempting it and post if you have any questions. It is not hard to do it is just time consuming. These instructions will also be useful for anyone who messed up there cam timing. Again if your gonna do the install yourself do it this way.
Signs of the timing being wrong- check engine lights, loss of power, no difference in power, excessively rough idle, cold misfires, misfires... this is not true in all cases, it does vary. So far it seems like the more modded Ecotec's tend to have sporadic multiple cylinder misfire codes and bank 1 system to rich codes. The misfire codes are from pahntom knock, lobey idle makes the knock sensor think the car smisfiring, if its an ongoing problem simple pull off the started remove the knock sesor and put a hard plstic or rubber washer inbetween the nock sensor and the block, it was desensatize it but you also need to run higher octane fuel to avoid detontaion, since the knock sensor wont pick up and small knock it wont do anythign about it but higher octane gas will help prevent it.
Instructions
First from in the engine bay. Disconnect the battery, then remove the 2 nuts that hold the fuel lines to the valve cover on the drivers side of the engine, gently pull the fuel line away and over the studs, then remove the studs which hold on a ground strap and the throttle cable holder. From there unplug the IDI cover and remove the 4 bolts that hold it in and the IDI cover itself. Once that is off remove all 4 of the spark plugs and the valve cover itself. Do not pry it off once the bolts are off because you could destroy the gasket, it will most likely stick if it does use a rubber mallet or a block of wood and GENTLY tap it off
Now from underneath the car. Raise the car and get the plastic cover in between the wheel and the engine off, its a couple push rivets and a few 7mm bolts I think it is. Take the serpentine belt off, use a 3/8 drive ratchet there is a spot to put it in the tensioner, have the ratchet set to off and pull the tensioner back and it will release tension from the belt, then just slide the belt off. Next step is to remove the crank pulley, I forget what size bolt it is but either use an impact to take it off, or stick a screwdriver through one of the pulley holes to keep it from spinning. If your trying to remove it without air tools its easier with the spark plugs still in the car, another way you could try is using the belt as a strap wrench around the pulley to keep the crank from spinning while your loosening the bolt, once its loose just slide a screw driver under it and it will pop/slide right off (you do not need a pulley puller to get it off, it is not pressed on). Put the crank pulley bolt NOT the pulley itself just the bolt back in the crank.
Now set the engine to TDC compression, spin the crank by using the bolt that hold the pulley on. Since the spark plugs are out you can use a long screw driver or something like it to stick in the #1 spark plug hole, DO NOT USE SOMETHING THAT CAN FIT ALL THE WAY IN THE CYLINDER!!! now with he screw driver in the spark plug hole slowly turn over the engine until the screw driver is at its highest point, since its resting on the piston top the piston will push it up. When the screw driver is at its highest point look at the marks on the cam gears. The Triangle shape on the exhaust cam should be aimed somewhere close to 10 o'clock position and the diamond on the intake should be facing close to the 2 o'clock position. If the piston is up and the marks aren't near there rotate the crank 1 full turn and then the marks should be were they are supposed to. They do not need to be 100% exact, just close.
The next step from here is to remove the power steering pump which locks into the intake cam, there are 2 bolts for it pull them out and just push the pump aside. Then remove the upper chain guide in between the cam gears.
Now from underneath the car again. Remove the belt tensioner, its a pain in the ass, you need to use a wrench because you can't fit a ratchet, take out the 1 bolt thats on the tensioner and it will fall right off. There is a dowel pin the tensioner drops into when you have it sitting there right so you can't reinstall it wrong. The next step is to remove the engine side cover, its a bunch of 10 MM bolts, they go around the outside of the cover and there is one that isn't on the outside edge, its towards the top left (firewall side) The little small cover on the cover with 4 bolts holding it on by the top left , leave it alone. There is a chain tensioner bolt for the balance shaft chain thats on the left, its a 10 MM hex head, remove that to, once those are out, pry up on and edge of it, its not gonna come off without a fight but be careful of the gasket, once it pops off make sure you do no try to remove the gasket, the gasket goes up under the upper motor mount so it wont come off, leave the gasket on the block. Put the crank pulley bolt NOT the pulley itself just the bolt back in the crank.
Once you are to this step go back up top and loosen up but don't remove the cam gear bolts on both cams. Now pull the timing chain tensioner bolt completely out. Its located on the passenger firewall side of the engine, its a big 1 1/4 inch bolt, remove it completely but be careful and do not drop it, you don't want it to come apart.
Go back under and find the chain tensioner itself, upper left from the crank, its the one that runs up the side of the engine, its long and is only actually attached with one bolt. Remove that one bolt that it pivots on, and push the tensioner out of the way away from the chain. There should be quite a bit of slack in the chain now.
Now go up top again and use something to hold the chain up, just so it doesn't fall all the way through to the bottom when you remove a cam gear, bungee the chain to the hood, slide a ruler or something under the chain in between the chain and area where the valve cover sits. Take a look and note where the lobes on the cams are facing for the #1 cylinder. Now start with one cam, you can remove the bearing caps, do these little by little, like 1/2 a turn on each bolt, then go back around and another half a turn on each bolt again until you can un thread them by hand. The one by the power steering pump will need to be tapped lose to same way as the valve cover. KEEP ALL CAPS IN THE SAME POSITION FACING THE SAME DIRECTION, they need to go on EXACTLY how they came off keep all the caps and bolts in EXACT order and replace in EXACT same position. The caps are numbered and have arrows on them so its not rocket science. Once you get the caps off remove the cam gear, its should only be hand tight at this time. you can let the chain hang but not let it fall in. Now remove the cam itself, you might have to tap it upwards for it to pop loose, be sure when you put the new cam in, to prelube the bearing surfaces of the caps and the head. Lay the the cam in so it is close having the lobes line up with where the stock cams lobes were, once the cam is in position torque them down in 3 steps ending with 89 in/lbs READ THAT CORRECTLY INCH POUNDS NOT FOOT POUNDS. The cap at the end of the intake cam by the power steering pump is 19 ft/lbs. Once the cam is on and tightened to spec put the cam gear back on, there is an off-centered key-way so it only fits on one way and do the other cam. When your done the chain will not be attached to anything up top at this point, just being held from falling using whatever method you rigged up earlier.
Now look at the chain itself, there will be 3 colored links, from what I've heard the color is different from year to year but there are 3 colored links. You need to line up the 3 colored links with the marks on the cams and crank and since the chain is loose you can freely rotate it to the position to make the markings like up. There will be a white dot on one of the teeth on the crank, one link to that tooth, one colored link to the triangle on the exhaust cam and the 3rd colored link to the diamond on the intake cam. You will most likely have to rotate one or both of the cams to get the marks to line up. Once all three colored links are lined up with the 3 timing marks turn the crank just a little bit to get all of the slack from the chain to the tensioner side of the engine. Reinstall the 10MM that holds the bottom of the tensioner chain guide then put the top tensioner bolt back in the big 1 1/4 inch one. Make sure all the marks still line up right, then spin the engine over by hand a few times to make sure nothing is hitting. If nothing is hitting then your done.
Reinstall everything you took up, I recommend putting the top back together first just in case you drop something down in the side cover it will still be off. The valve cover and IDI cover also get torqued to 89 in/lbs again INCH POUNDS. Remember to put the upper chain guide back on and the ground strap that goes to the cam cover stud. Then reinstall the bottom last in reverse order of disassembly. Once everything is back together reconnect the battery and start it up."
NOTE: I WROTE THIS UP FOR ECOTEC CAVALIERS but seeing as the engines are all but identical this will work on cobalts, they have only made very small minor changes.
Anyways, my original write up....
"There is allot of info going around about cam installs on an ecotec so I wrote up a step by step from beginning to end. There is a faster way to do a cam install then this but its not worth the risk, a couple people have had the valves hit pistons and I think everyone has messed up the cam timing and had to redo it. If you do it this way your timing will be right and there will be no valve to piston contact. I suggest you read this all the through beginning to end before attempting it and post if you have any questions. It is not hard to do it is just time consuming. These instructions will also be useful for anyone who messed up there cam timing. Again if your gonna do the install yourself do it this way.
Signs of the timing being wrong- check engine lights, loss of power, no difference in power, excessively rough idle, cold misfires, misfires... this is not true in all cases, it does vary. So far it seems like the more modded Ecotec's tend to have sporadic multiple cylinder misfire codes and bank 1 system to rich codes. The misfire codes are from pahntom knock, lobey idle makes the knock sensor think the car smisfiring, if its an ongoing problem simple pull off the started remove the knock sesor and put a hard plstic or rubber washer inbetween the nock sensor and the block, it was desensatize it but you also need to run higher octane fuel to avoid detontaion, since the knock sensor wont pick up and small knock it wont do anythign about it but higher octane gas will help prevent it.
Instructions
First from in the engine bay. Disconnect the battery, then remove the 2 nuts that hold the fuel lines to the valve cover on the drivers side of the engine, gently pull the fuel line away and over the studs, then remove the studs which hold on a ground strap and the throttle cable holder. From there unplug the IDI cover and remove the 4 bolts that hold it in and the IDI cover itself. Once that is off remove all 4 of the spark plugs and the valve cover itself. Do not pry it off once the bolts are off because you could destroy the gasket, it will most likely stick if it does use a rubber mallet or a block of wood and GENTLY tap it off
Now from underneath the car. Raise the car and get the plastic cover in between the wheel and the engine off, its a couple push rivets and a few 7mm bolts I think it is. Take the serpentine belt off, use a 3/8 drive ratchet there is a spot to put it in the tensioner, have the ratchet set to off and pull the tensioner back and it will release tension from the belt, then just slide the belt off. Next step is to remove the crank pulley, I forget what size bolt it is but either use an impact to take it off, or stick a screwdriver through one of the pulley holes to keep it from spinning. If your trying to remove it without air tools its easier with the spark plugs still in the car, another way you could try is using the belt as a strap wrench around the pulley to keep the crank from spinning while your loosening the bolt, once its loose just slide a screw driver under it and it will pop/slide right off (you do not need a pulley puller to get it off, it is not pressed on). Put the crank pulley bolt NOT the pulley itself just the bolt back in the crank.
Now set the engine to TDC compression, spin the crank by using the bolt that hold the pulley on. Since the spark plugs are out you can use a long screw driver or something like it to stick in the #1 spark plug hole, DO NOT USE SOMETHING THAT CAN FIT ALL THE WAY IN THE CYLINDER!!! now with he screw driver in the spark plug hole slowly turn over the engine until the screw driver is at its highest point, since its resting on the piston top the piston will push it up. When the screw driver is at its highest point look at the marks on the cam gears. The Triangle shape on the exhaust cam should be aimed somewhere close to 10 o'clock position and the diamond on the intake should be facing close to the 2 o'clock position. If the piston is up and the marks aren't near there rotate the crank 1 full turn and then the marks should be were they are supposed to. They do not need to be 100% exact, just close.
The next step from here is to remove the power steering pump which locks into the intake cam, there are 2 bolts for it pull them out and just push the pump aside. Then remove the upper chain guide in between the cam gears.
Now from underneath the car again. Remove the belt tensioner, its a pain in the ass, you need to use a wrench because you can't fit a ratchet, take out the 1 bolt thats on the tensioner and it will fall right off. There is a dowel pin the tensioner drops into when you have it sitting there right so you can't reinstall it wrong. The next step is to remove the engine side cover, its a bunch of 10 MM bolts, they go around the outside of the cover and there is one that isn't on the outside edge, its towards the top left (firewall side) The little small cover on the cover with 4 bolts holding it on by the top left , leave it alone. There is a chain tensioner bolt for the balance shaft chain thats on the left, its a 10 MM hex head, remove that to, once those are out, pry up on and edge of it, its not gonna come off without a fight but be careful of the gasket, once it pops off make sure you do no try to remove the gasket, the gasket goes up under the upper motor mount so it wont come off, leave the gasket on the block. Put the crank pulley bolt NOT the pulley itself just the bolt back in the crank.
Once you are to this step go back up top and loosen up but don't remove the cam gear bolts on both cams. Now pull the timing chain tensioner bolt completely out. Its located on the passenger firewall side of the engine, its a big 1 1/4 inch bolt, remove it completely but be careful and do not drop it, you don't want it to come apart.
Go back under and find the chain tensioner itself, upper left from the crank, its the one that runs up the side of the engine, its long and is only actually attached with one bolt. Remove that one bolt that it pivots on, and push the tensioner out of the way away from the chain. There should be quite a bit of slack in the chain now.
Now go up top again and use something to hold the chain up, just so it doesn't fall all the way through to the bottom when you remove a cam gear, bungee the chain to the hood, slide a ruler or something under the chain in between the chain and area where the valve cover sits. Take a look and note where the lobes on the cams are facing for the #1 cylinder. Now start with one cam, you can remove the bearing caps, do these little by little, like 1/2 a turn on each bolt, then go back around and another half a turn on each bolt again until you can un thread them by hand. The one by the power steering pump will need to be tapped lose to same way as the valve cover. KEEP ALL CAPS IN THE SAME POSITION FACING THE SAME DIRECTION, they need to go on EXACTLY how they came off keep all the caps and bolts in EXACT order and replace in EXACT same position. The caps are numbered and have arrows on them so its not rocket science. Once you get the caps off remove the cam gear, its should only be hand tight at this time. you can let the chain hang but not let it fall in. Now remove the cam itself, you might have to tap it upwards for it to pop loose, be sure when you put the new cam in, to prelube the bearing surfaces of the caps and the head. Lay the the cam in so it is close having the lobes line up with where the stock cams lobes were, once the cam is in position torque them down in 3 steps ending with 89 in/lbs READ THAT CORRECTLY INCH POUNDS NOT FOOT POUNDS. The cap at the end of the intake cam by the power steering pump is 19 ft/lbs. Once the cam is on and tightened to spec put the cam gear back on, there is an off-centered key-way so it only fits on one way and do the other cam. When your done the chain will not be attached to anything up top at this point, just being held from falling using whatever method you rigged up earlier.
Now look at the chain itself, there will be 3 colored links, from what I've heard the color is different from year to year but there are 3 colored links. You need to line up the 3 colored links with the marks on the cams and crank and since the chain is loose you can freely rotate it to the position to make the markings like up. There will be a white dot on one of the teeth on the crank, one link to that tooth, one colored link to the triangle on the exhaust cam and the 3rd colored link to the diamond on the intake cam. You will most likely have to rotate one or both of the cams to get the marks to line up. Once all three colored links are lined up with the 3 timing marks turn the crank just a little bit to get all of the slack from the chain to the tensioner side of the engine. Reinstall the 10MM that holds the bottom of the tensioner chain guide then put the top tensioner bolt back in the big 1 1/4 inch one. Make sure all the marks still line up right, then spin the engine over by hand a few times to make sure nothing is hitting. If nothing is hitting then your done.
Reinstall everything you took up, I recommend putting the top back together first just in case you drop something down in the side cover it will still be off. The valve cover and IDI cover also get torqued to 89 in/lbs again INCH POUNDS. Remember to put the upper chain guide back on and the ground strap that goes to the cam cover stud. Then reinstall the bottom last in reverse order of disassembly. Once everything is back together reconnect the battery and start it up."
