Oil leaking into engine cylinder, burnt spark plug, smoke out of exhaust

Tiny
DKINGETH
  • MEMBER
  • 2008 CADILLAC STS
  • 4.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 108,000 MILES
Oil leaking into cylinder number three, burning the spark plug. Smoke coming out of exhaust (mostly on startup and accelerating), not losing coolant, not overheating, no oil in coolant, no coolant in oil.

Any idea what is could mean?
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Monday, August 27th, 2018 AT 7:23 PM

8 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi and thanks for using 2CarPros. Com.

It sounds like there is an issue with the valve seal in the cylinder. The engine valves are in the cylinder head above the cylinder. Often times, the seals will deteriorate allowing oil to bypass them and enter the cylinder through the valve. Additionally, there could be an issue with the valve guide itself. The result is blue smoke on start up and often times heavy acceleration. When driving at a normal pace, you will not see the oil being burned. I attached an exploded view of the cylinder head. Locate item number 324. That is the seal I am referring to. Here is the legend for all the parts listed in the picture:

300 - Left Cylinder Head
301 - Right Cylinder Head
302 - Left Cylinder Head Gasket
303 - Right Cylinder Head Gasket
310 - Cylinder Head Bolt - M11
311 - Cylinder Head Front Bolt - M6
312 - Cylinder Head Coolant Hole Expansion Plug
313 - Cylinder Head Coolant Hole Plug
314 - Cylinder Head Coolant Hole Plug Seal Ring
315 - Cylinder Head Oil Gallery Plug
315 - Cylinder Head Oil Gallery Plug
316 - Cylinder Head Oil Gallery Plug Ring
316 - Cylinder Head Oil Gallery Plug Ring
317 - Engine Oil Gallery Restrictor
317 - Engine Oil Gallery Restrictor
320 - Exhaust Valve
321 - Intake Valve
322 - Valve Rocker Arm Assembly
323 - Hydraulic Valve Lash Adjuster Assembly
324 - Valve Stem Oil Seal
325 - Valve Spring
326 - Valve Spring Cap
327 - Valve Stem Key
330 - Left Exhaust Camshaft
331 - Left Intake Camshaft
332 - Right Intake Camshaft
333 - Right Exhaust Camshaft
334 - Cylinder Head Front Camshaft Cap
335 - Cylinder Head Front Camshaft Cap
336 - Cylinder Head Camshaft Cap
337 - Cylinder Head Camshaft Cap Bolt
337 - Cylinder Head Camshaft Cap Bolt
337 - Cylinder Head Camshaft Cap Bolt
338 - Camshaft Sprocket Locating Pin
340 - Left Camshaft Position Actuator Housing
341 - Right Camshaft Position Actuator Housing
342 - Left Camshaft Position Actuator Housing Gasket
343 - Right Camshaft Position Actuator Housing Gasket
344 - Camshaft Position Actuator Housing Pin
345 - Camshaft Position Actuator Housing Stud - Short
345 - Camshaft Position Actuator Housing Stud - Short
346 - Camshaft Position Actuator Housing Stud - Long
346 - Camshaft Position Actuator Housing Stud - Long
347 - Camshaft Position Actuator Housing Bolt
625 - Cylinder Head Exhaust Manifold Stud
711 - Engine Coolant Temperature Sensor
725 - Camshaft Position Sensor
726 - Camshaft Position Sensor O-Ring
727 - Camshaft Position Sensor Bolt
735 - Camshaft Position Actuator Magnet
736 - Camshaft Position Actuator Magnet Bolt
737 - Camshaft Position Actuator Magnet Plug
738 - Camshaft Position Actuator Magnet Plug O-Ring

I hope this helps. Let me know if you have other questions.

Take care,
Joe
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Monday, August 27th, 2018 AT 7:36 PM
Tiny
DANNY L
  • EXPERT
Hello, I am Danny.

That usually means the o-rings sealing the spark plug tubes from the valve cover is leaking. Pretty common. I have attached a picture and circled in ted where the valve cover/spark plug tubes are leaking oil into the spark plugs. Would you like instructions how to fix yourself? Hope this helps and feel free to ask any questions if needed. Thanks for using CarPros.
Danny-
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Monday, August 27th, 2018 AT 7:42 PM
Tiny
DKINGETH
  • MEMBER
Please send instructions on how to fix. Thank you.
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Tuesday, August 28th, 2018 AT 3:42 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi again. Danny indicated there may be a leak in the spark plug tube due to an o-ring. That will not cause oil to come out of the exhaust. It will, however, allow oil to enter the tube and get on the outside of the plug. Danny, is that correct or am I missing something?
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Wednesday, August 29th, 2018 AT 6:13 PM
Tiny
DANNY L
  • EXPERT
Hello again.

Hey Joe. He is just noticing engine oil leaking into the spark plug tubes from the valve cover. It is a simple valve cover gasket replacement.
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Thursday, August 30th, 2018 AT 1:09 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Okay, I misunderstood. He said he gets smoke from the exhaust so I figured it was getting into the combustion chamber.

Regardless, here are the directions for replacing the valve cover gaskets. There are three separate sets of directions. The first and second show how the valve cover and gaskets are removed. (Left and right sides are separate) The third show how to take apart the valve cover and replace the spark plug port seal.
_________________________________

Camshaft Cover Replacement - Left Side The first 7 pictures correlate to these directions.

Removal Procedure
1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement (See: Fuel Injector > Removal and Replacement).
2. Disconnect the positive crankcase ventilation (PCV) fresh air tube from the left camshaft cover.
3. Remove the bank 2 ignition coils. Refer to Ignition Coil Replacement - Bank 2 (See: Ignition Coil > Removal and Replacement).
4. Remove the bolt connecting the ground strap to the left camshaft cover.
5. Remove the bolt securing the oil level indicator tube to the left cylinder head and reposition the tube away from the camshaft cover.
6. Remove the camshaft cover bolts.
7. Lift the camshaft drive end of the camshaft cover up.
8. Remove the camshaft cover.
9. Discard the camshaft cover gasket and spark plug port seals if there is any evidence of damage or if the seal comes out of the groove in the cover during removal.
10. Clean the gasket mating surface on the cylinder head.
11. Clean and inspect the camshaft cover.

Installation Procedure
1. Install a new camshaft cover gasket to the camshaft cover if necessary.
2. Place a small amount of sealant at the split line (1, 2) of the left cylinder head and the left camshaft position actuator housing. Refer to Adhesives, Fluids, Lubricants, and Sealers (See: Engine > Mechanical).

Important: Be careful to prevent the exposed section of the camshaft cover gasket from being damaged by the edge of the cylinder head casting.

3. Work the camshaft cover into position by pivoting the cover down and aligning the bolt holes.
Notice: Refer to Fastener Notice (See: Vehicle > Vehicle Damage Warnings > Fastener Notice).

4. Install the camshaft cover bolts.

Tighten the bolts to 10 N.M (89 lb in).
5. Install the bolt connecting the left camshaft cover ground strap to the left camshaft cover.

Tighten the bolt to 10 N.M (89 lb in).

6. Rotate the oil level indicator tube back into its original position and install the bolt securing the tube to the cylinder head.

Tighten the bolt to 10 N.M (89 lb in).

7. Install the bank 2 ignition coils. Refer to Ignition Coil Replacement - Bank 2 (See: Ignition Coil > Removal and Replacement).
8. Connect the PCV fresh air tube to the left camshaft cover.
9. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement

________________________________________________________________________________________

Right side (pictures 8 to 23 correlate with these directions)

Camshaft Cover Replacement - Right Side

Removal Procedure
1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement (See: Fuel Injector > Removal and Replacement).
2. Disconnect the positive crankcase ventilation (PCV) dirty air tube from the camshaft cover.
3. Remove the front air inlet housing panel. Refer to Air Inlet Housing Front Panel Replacement (See: Air Duct > Removal and Replacement > Air Inlet Housing Front Panel Replacement).
4. Remove the battery tray. Refer to Battery Tray Replacement (See: Battery Tray > Removal and Replacement > Battery Tray Replacement).
5. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (See: Maintenance > Service Intervals).
6. Remove the front air deflector. Refer to Front Air Deflector Replacement (See: Air Dam > Removal and Replacement > Front Air Deflector Replacement).
7. Remove the bolts securing the wire harness bracket to the cylinder head.
8. Lower the vehicle.
9. Remove the bank 1 ignition coils. Refer to Ignition Coil Replacement - Bank 1 (See: Ignition Coil > Removal and Replacement).
10. Disconnect the cable harness clips at the front of the camshaft cover and position the cable harness aside.
11. Remove the bolt connecting the ground strap to the right camshaft cover.
12. Remove the camshaft cover bolts.
13. Remove the camshaft cover.
14. Discard the camshaft cover gasket and spark plug port seals if there is any evidence of damage or if the seal comes out of the groove in the cover during removal.
15. Clean and inspect the camshaft cover. Refer to Camshaft Cover Cleaning and Inspection ().

Installation Procedure

Important: Be careful to prevent the exposed section of the camshaft cover seal from being damaged by the edge of the cylinder head casting.

1. Install the camshaft cover gasket as required.
2. Place a small amount of sealant at the split line (1, 2) of the right cylinder head and the right camshaft position actuator housing. Refer to Adhesives, Fluids, Lubricants, and Sealers (See: Engine > Mechanical).
3. Install the camshaft cover.
Notice: Refer to Fastener Notice (See: Vehicle > Vehicle Damage Warnings > Fastener Notice).

4. Install the camshaft cover bolts installing the ground strap to the camshaft cover.

Tighten the bolts to 10 N.M (89 lb in).

5. Install the bank 1 ignition coils. Refer to Ignition Coil Replacement - Bank 1 (See: Ignition Coil > Removal and Replacement).
6. Connect the cable harness clips to the front of the camshaft cover.
7. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (See: Maintenance > Service Intervals).
8. Install the bolts securing the wire harness bracket to the cylinder head.

Tighten the bolts to 45 N.M (33 lb ft).

9. Install the front air deflector. Refer to Front Air Deflector Replacement (See: Air Dam > Removal and Replacement > Front Air Deflector Replacement).
10. Lower the vehicle.
11. Install the battery tray. Refer to Battery Tray Replacement (See: Battery Tray > Removal and Replacement > Battery Tray Replacement).
12. Install the front air inlet housing panel. Refer to Air Inlet Housing Front Panel Replacement (See: Air Duct > Removal and Replacement > Air Inlet Housing Front Panel 13. Connect the PCV dirty air tube to the camshaft cover.
14. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement (See: Fuel Injector > Removal and Replacement).

_______________________________________________________________________________________

Valve cover disassembly ( the last three pictures correlate with these directions)
84. CAMSHAFT COVER DISASSEMBLE
Camshaft Cover Disassemble
1. Remove the left camshaft cover gasket and discard.
2. Remove the left spark plug port seals and discard.
3. Remove the right camshaft cover gasket and discard.
5. Remove the camshaft cover bolts.
6. Remove the camshaft cover bolt grommets.

_____________________________________________________________________________________

I hope this helps. Let us know if you have other questions.

Take care,
Joe
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Thursday, August 30th, 2018 AT 6:00 PM
Tiny
DKINGETH
  • MEMBER
Thank you so much for sending directions on how to replace valve cover gasket. However, after looking at them it may be too big of a job for me, but I appreciate you sending them. Thank you very much.
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Thursday, August 30th, 2018 AT 6:31 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Happy to help. The directions are long but it really is not that hard of a job. If you do it and run into any trouble, let me know and I can try to help from here. By the way. I am sorry if I confused you at first. I thought you were burning the oil and the smoke was coming out the exhaust at start up and under acceleration.

Regardless, have a good weekend and take care.

Joe
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Friday, August 31st, 2018 AT 5:28 PM

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