Vacuum leak I have an 05 chevy colorado 3.5 5cyl. I noticed a vacuum leak on the hose that goes from the valve cover to the intake manifold.Problem is that in order to fix the leak,the black plastic cover over the intake manifold needs to be removed or at least loosened.Any idea how this cover can be removed?

First check for an air intake leak or a vacuum leak from a vacuum hose causing more air to enter the intake manifold. Also make sure that there is not something that is keeping the throttle plate open. Maybe do an intake throttle cleaning.

if the intake manifold comes back over the rocker cover then you will most probably have to remove it as the cover has to be lifted up over the rockers and cam shaft. IT will facilitate a good job with a proper sealing gasket.

Big breather from valve cover to air cleaner, the small vac line runs from there to the FPR.



These next are standing in front of the car:

Intake manifold lower outer runs to EZL

Intake manifold lower inner (right side) goes to switchover vac valve on driver fender. The other side of this vac valve goes to the throttle body

Intake manifold lower inner (left side) goes to switchover vac valves on passenger side fender. These then go back to the EGR valve once making a loop under the distributor cap for whatever reason.

Intake manifold rear runs to a 'three' way valve (or 'Y' connector) on the secondary firewall. This is usually a vac leak.

Sorry I don't have the diagram, but I do have a diagram of the engine and component locations. Your vacuum system is fairly simple. You have a MAP sensor attached to the air cleaner. I have pasted a picture below. It has one electrical connector and one vacuum hose that goes to the intake manifold or the throttle body.
Behind the right headlight is your evap canister. This will have a hose or line running to the fuel tank. Then it will have another hose going to the purge valve. The purge valve should be close by and it has a connector plus another hose that goes to the intake manifold.
Then you have the PCV hose that goes from the PCV valve in the valve cover to the air cleaner or intake manifold. I think yours just has a hose from the air cleaner and the rest is internal.
There is one more vacuum hose, and that is the bog one that goes from the intake manifold (or throttle body--looks to me like there are a couple of vacuum ports on the back side of the throttle body, and there may be a "T" on one of the hoses) to the brake booster. It this one was off, the engine would not run, as the vacuum draw is large. Please let me know if you cannot figure it out from these instructions and provide a picture, if you can.

MAP sensor:


purge valve:

CHECK FOR VACUM LEAKS AT INTAKE MANIFOLD AND ECT TEMP READING COULD BE OFF,

Cylinder Head Removal & Installation SOHC To Remove:

1. Relieve fuel system pressure.
2. Remove timing belt cover. Camshaft timing marks
   
   
3. Turn crankshaft until timing mark on front housing and the arrow "2" on the camshaft pulley align.
4. Loosen lock bolt on tensioner.
5. Pry tensioner away from timing belt and tighten lock bolt to relieve tension on the timing belt.
6. Remove timing belt from camshaft pulley.
7. Disconnect battery negative cable.
8. Remove 3 bolts that secure accelerator cable and air intake hose to cylinder head cover.
9. Detach accelerator cable and place off to side.
10. Remove the following;
    • Air hose
    • Air ISC air hose
    • Breather hose
    • Vacuum hose from air intake hose
11. Disconnect mass air flow sensor electrical connector.
12. Remove air intake hose.
13. Remove PCV valve from cylinder head cover.
14. Remove ISC air hose from idle speed actuator.
15. Remove air hose from behind intake manifold.
16. Remove 2 screws from high tension wire protectors.
17. Detach wire loom from holder at rear of cylinder head cover.
18. Detach vacuum tube at rear of cylinder head cover.
19. Remove vacuum pipe. Cylinder Head Cover
    
    
20. Remove 7 cylinder head cover bolts.
21. Remove cylinder head cover and gasket.
22. Disconnect 2 ignition coil electrical connectors.
23. Disconnect 2 fuel injection electrical connectors at rear of cylinder head.
24. Disconnect the following electrical connectors;
    • Oxygen sensor
    • Throttle position sensor
    • Idle speed actuator
    • Oil pressure switch
    • EGR vacuum solenoid valve at intake manifold
25. Disconnect heater hose from elbow.
26. Disconnect brake booster vacuum hose and cruise control vacuum hose from surge tank.
27. Detach wire harness from rear of cylinder head.
28. Disconnect purge control solenoid vacuum hose from intake manifold.
29. Disconnect fuel hose from fuel connector assembly.
30. Remove grounding bracket.
31. Remove 4 bolts and intake manifold bracket.
32. Remove starter.
33. Detach water bypass hose from bypass pipe.
34. Disconnect water hoses from oil cooler.
35. Disconnect fuel hose from fuel pipe.
36. Remove exhaust manifold heat shield.
37. Remove exhaust flange nuts and front exhaust bracket bolt.
38. Lower exhaust system. Cylinder head bolt loosening sequence
    
    
39. Loosen cylinder head bolts in 3 steps in proper sequence.
40. Remove cylinder head bolts and washers.
41. Remove cylinder head, intake manifold and exhaust manifold as an assembly.

To Install:

1. Install NEW cylinder head gasket.
2. Install cylinder head, intake manifold and exhaust manifold as an assembly.
3. Tighten cylinder head bolts in 3 steps in reverse sequence that was used during removal. Tighten bolts to 62 ft lb (84 Nm).
4. Install front exhaust bracket bolt. Tighten bolt to 20 ft lb (27 Nm).
5. Install NEW lower exhaust flange gasket and 3 nuts. Tighten nuts to 24 ft lb (31 Nm).
6. Install exhaust manifold heat shield. Tighten nuts to 35 in lb (4 Nm).
7. Connect fuel hose to pipe.
8. Connect 2 hoses to oil cooler.
9. Attach water bypass hose to bypass pipe.
10. Install starter and bolts. Tighten bolts to 34 ft lb (46 Nm).
11. Install intake manifolds bracket and 4 bolts. Tighten bolts to 32 ft lb (45 Nm).
12. Install grounding bracket.
13. Connect fuel hose to fuel connector assembly.
14. Connect the following electrical connectors;
    • Oxygen sensor
    • Throttle position sensor
    • Idle speed actuator
    • Oil pressure switch
    • EGR vacuum solenoid valve at intake manifold
15. Connect purge control solenoid vacuum hose to intake manifold.
16. Attach wire harness from rear of cylinder head.
17. Connect brake booster vacuum hose and cruise control vacuum hose to surge tank.
18. Connect heater hose to elbow.
19. Connect 2 fuel injection electrical connectors at rear of cylinder head.
20. Connect 2 ignition coil electrical connectors.
21. Install cylinder head cover.
22. Install 7 cylinder head cover bolts. Tighten bolts to 60 in lb (7 Nm).
23. Install vacuum pipe and 2 bolts at rear of cylinder head cover. Tighten bolts to 60 in lb (7 Nm).
24. Connect vacuum tube to pipe.
25. Connect loom holder to rear of cylinder head cover.
26. Install 2 screws to high tension wire protectors.
27. Install air hose to behind intake manifold.
28. Install ISC air hose to idle speed actuator.
29. Install PCV valve to cylinder head cover.
30. Install air intake hose.
31. Connect mass air flow sensor electrical connector.
32. Install the following;
    • Air hose
    • Air ISC air hose
    • Breather hose
    • Vacuum hose from air intake hose
33. Attach accelerator cable.
34. Install 3 bolts that secure accelerator cable and air intake hose to cylinder head cover. Timing belt pulley timing marks
    
    NOTE: Timing belt pulley timing mark and timing mark must be aligned.
    Camshaft timing marks
    
    NOTE: The arrow at "2" on camshaft pulley must be aligned with timing mark on front housing.
    
35. Install timing belt.
36. Install timing belt cover.
37. Pressurize fuel system.
38. Start engine and check ignition timing.

The best thing to do is run a trouble code check on it.
Other than that check for a vaccum leak, the EGR valve, or the idle air control valve.

P0302 is random misfire on cylinder #2.

Most comment cause is vacuum leak at the intake manifold and vacuum hose.

If you valve cover is leaking oil on then DO THE HOLD JOB.

Remove valve cover to gain access the intake manifold.

Change the intake gasket and valve cover gasket.

remove oil cap steam an it should just lift off

plastic cover must come off to repair hose< hope you have a garage friend he will help you if not post it again i will ask my mechinic.