I am not a mechanic. Please only use this as a Guide. Take all necessary precautions when working on your car including gloves and eye wear protection. I undertook this repair with the help of a Gregorys Mechanic Book and generalised knowledge of my Ecotec Motor and components. If I could do it I am sure most others could as well. The repair by myself took a hard 6 hours of work. If you can't spare at least a day then I would leave this to a mechanic.
Things you will need:
Engine Oil, Oil flush (approx $35 bucks)
Coolant, coolant flush, new radiator cap (approx $50 bucks as I use genuine Castrol Coolant)
Thermostat, Thermostat Gasket (Ecotec Motor Tridon TTG46) (approx $24 bucks)
New Inlet Manifold Gasket Set, Instant Gasket Sealant RTV or equivalent (approx $140 bucks as I used a lifetime gasket set aluminium one)
A good set of Screw Drivers and Ratchets, a rubber mallet, Fuel Disconnect Tool
Turps/Petrol, Razor Blade tool
I would guess this job would cost 4 hours labour in a mechanics shop, the current going rate is about $100 bucks an hour. Plus your guaranteed a mechanic would be using cheap coolant, oils, the cheap plastic gasket set, not quality products like I have used. So assuming this the mechanics price would be around $500 - $600 bucks, could be wrong though maybe someone can assist with this. So easily I've saved $200 - $300 bucks doing it myself and now I've got more of an understanding of my engine from doing it.
Turn engine on. Open bonnet and remove Fuel Relay Fuse from Fuse boxs in engine bay. Check your diagram to confirm which fuse it is. Wait until engine stalls. Attempt to crank at least 10 times to try and reduce fuel in fuel lines and injector fuel rails.
Remove Battery. This is to prevent any unintended sparks from hitting a Positive lead in the Engine Bay which could potentially damage components or computer hardware.
Time to get dirty. Start by removing the air box and piping to the plenum. Don't forget to remove the Air Box Sensor and the MAF sensor.
Remove the Throttle Bracket which is attached by three bolts on the rear. Pry off the throttle cable from the nob with a screw driver or similar. If you have Cruise control there will be a second cable and nob to pry off. (Not %100 percent sure as I don't have Cruise Control).
Unbolt the EGR (Only for VT-VY). As I am aware VS does not have a EGR.
Remove your Engine belt. Unbolt your alternator. Theres two screws plus a ground screw underneath. Theres also a support bracket which needs to be unscrewed. At the rear is a another ground i think which is surrounded by rubber. Don't forget to unplug the clip at the rear of the alternator. If all bolts remove the alternator should slide up and out of the supporting metal brackets.
Ok now is the time to remove the coolant from the system. Undo the bottom radiator hose allowing coolant to come out. Have a tray underneath to catch the coolant to dispose of it. Remember Environment and dispose of coolant correctly. Remove the top radiator hose. Allow as much of the coolant to drain and then remove the thermostat housing by undoing the two bolts. Attached to the bottom of the housing will be the old paper gasket. Scrap this off using a razar or petrol/turps. Remove the thermostat, Discard if you have a new one. If reusing make sure thermostat still works. Test in boiling water. It should open up in Boiling water and close when cold.
Unplug all the injectors and fuel rail lines that enter the body on the drivers side using the fuel disconnect tool. Undo all the vacuum lines from the rear of the plenum. Not all of them need to be removed as one or to goes to the fuel lines which you disconnect which can go with the hole plenum when pulled off.
Time to remove the Tensior Pulley Assembly. undo bolts underneath. Undo the heater radiator pipes that connect to the metal pipe. Once all bolts undo slowly slide the metal cylinder out from the tensior pulley assembly and remove the whole assembly.
Attempt to remove any coolant left in the lower manifold. After this make a quick check around the engine bay making sure no bolts or cables are in the way for when you remove the plenum/lower manifold.
Remove the 12 bolts that attach the lower manifold to the engine. When reassembling the Torque range is between 12 - 16 NM which is quite weak. You may notice when undoing these bolts some will be extremely loose.
Ok if you have removed everything correctly the whole plenum/TPS/ICA and lower manifold should come free revealing the intake manifold gasket. This is were I could see I had a small leak near cylidner 1 - 3. Also a small leak at the rear of the block.
You need to clean the matting surfaces from which the gasket was sitting on. Do so using a razor, turps and or fuel until clean. Do the same on the bottom of the lower manifold. Be careful not to disturb the injector nozzels which poke through. While doing this step cover the engine compartment to prevent foreign objects getting into it. If you suspect anything has fallen in you need to flush your oil and replace the oil ASAP.
Once you are satisfied both matting surfaces are clean position the new gaskets. Place RTV Sealant or equivalent in the four corners to provide a seal and stop leaks. Apply librally as it won't hurt as long as you get it in the right place. RTV Sets in 10 minutes so be quick to replace the plenum/lower manifold back on the engine.
Bolt up 12 bolts on manifold to 12 - 16 NM Torque and let set for 2 hrs or longer if you have to spare.
Reverse of Steps 1 to 12 making sure you set thermostat correctly with new gasket. (I put in a cooler Thermostat the 81 Degrees one, The car runs cooler during highway driving and doesn't heat up as quickly during city stop and go, not really necessary as long as your cooling system is in A1 condition.)
Put in fresh coolant with correct water/coolant ratio 33% - 50%. Double check all plugs/wires/bolts are re attached and correct. Replace fuse relay and battery.
If you are satisfied everything is correct and back together start engine. Check for leaks in coolant system. and around manifold gaskets. After a week replace oil and coolant to remove any foreign objects. Then you are done.
Last edited by Hot-Rod; 05-02-2012 at 02:06 PM. Reason: Text never saved when first created
Pictures look good, but can you add more information? Like, a step by step process?
Unbelievable. I spent an hour typing up over 20 steps. Obviously it didn't work but the pictures did. I'll re type everything a little later.
#### man your engines noice and clean inside lol nice write up too
Yeah thanks. Without it being so clean I wouldn't have been able to spot the leak so easily. Big advantage to having engine/bay clean. Only takes a minute to clean it.
Perrrrfect! just what I was after, not sure i can do that myself and the boys not a car enthusiast like myself but theres only one way to learn!
Nice write up mate. What engine oil do you use? Just interested because the inside of your engine is so clean.
Is it worth replacing the thermostat even though mine doesn't appear to be defective? I know I still need to remove it and to replace the gasket.
Yeah, $24 doesn't seem bad at all, I was thinking the same thing... saves doing it in another 50,000kms or whatever it takes
I actually followed this tutorial and replaced those gaskets , helped so much rather big job but was worth it no oil leaks what so ever now !
ps ( be aware that diffrent series eco tec motors had diffrent valley cover gaskets)
Just curious as to any tell tale signs that your LIM gasket is gone. I cant see any visible leaks from the outside but the engine seems low on power and wondering if there's a vacuum leek. Clutch is gone which i think is just making me paranoid but would like to know anyway
This engine is super clean inside and out. Nice write up.
great job on the write up mate. did you get the alum gasket set from mace engineering or somewhere else in aus?
I have found it on an online parts place called zz engineering for $90 delivered but i was wondering if your stated price included the cost of the RTV you used there.
just wondering where you got the alum gasket set from and how much?
You Can Get them from here - Inlet Manifold Gaskets - Mace Engineering Group
G'day everyone. Yeah got the Gaskets from Mace. Engines clean because I do the Oil Service regularly by myself with decent oil. Also Low KMs.
At a minimum I would torque the top manifold bolts that hold the manifold to the engine as they are a weake torque and are prone to coming loose. Bolt up 12 bolts on manifold to 12 - 16 NM Torque. Hope this helps.
Just figured I'd add my 2 cents. I just did this job today, and started the engine up only to discover I had a coolant leak. Turned out I'd made the silly mistake of not checking the O-ring on the heater outlet pipe. Nearly put me into a panic attack thinking somehow I had a massive coolant leak out of the front of the new seal XD
So anyway, check your O-rings!! Especially that one! It had torn, fortunately I had a couple of spare ones which were the right size.
Thanks again for the write-up, I used it in conjunction with the workshop manual.
Great write up, only thing I would suggest is the need to be aware that with the inlet ports exposed it is possible to accidently drop or place foreign matter or object(s) into the inlet and unless retrieved serious engine damage could result.
I can also recommend that when you attempt this, to have decent tools. trying to loosen the bolt for the heater crossover pipe, my cheap'n'nasty spanner kept rounding the nut. Went and borrowed a mates Kincrome spanner and the nut came off straight away. I wasted an hour using the cheapo one.
Thanks for this thread save me asking the question. Looks like I have an inlet manifold to remove