Slinging oil
Thread Starter
Registered User
Joined: Sep 2019
Posts: 58
Slinging oil
Theres a significant oil leak on the front of my LT1, I'm thinking its the timing chain cover gasket. Oil is slinging everywhere in front of the engine and some has even gotten into the throttle body and all around the water pump and optispark. So, I'll be inspecting the optispark for moisture damage to decide if not to replace the whole distributor or just clean it well. Could the leak be anything else?
Administrator
Joined: Nov 1998
Posts: 71,086
From: Hell was full so they sent me to NJ
Re: Slinging oil
There are three oil seals in the timing cover - water pump drive shaft, Opti cam pin drive, and crankshaft. Any one of those would be more likely to “sling” oil than the timing cover gasket.
http://shbox.com/ci/front_cover.jpg
On a 96, there is also the possibility of the crank position sensor leaking, but that would drip, rather than sling.
http://shbox.com/ci/front_cover.jpg
On a 96, there is also the possibility of the crank position sensor leaking, but that would drip, rather than sling.
Registered User
Joined: Jun 2003
Posts: 1,112
Re: Slinging oil
OP
of the front timing cover seals/gaskets...the WP drive seal is the most common and prone to leak. You need some form of "tool" to install one but otherwise not a difficult job.
if your opti is a AC Delco DO NOT get rid of it. Just remove cap, rotor and metal wheel and carefully clean the inside of it if, very likely, oil did get inside the opti. Use blue loc tite on the rotor screws
of the front timing cover seals/gaskets...the WP drive seal is the most common and prone to leak. You need some form of "tool" to install one but otherwise not a difficult job.
if your opti is a AC Delco DO NOT get rid of it. Just remove cap, rotor and metal wheel and carefully clean the inside of it if, very likely, oil did get inside the opti. Use blue loc tite on the rotor screws
Thread Starter
Registered User
Joined: Sep 2019
Posts: 58
Re: Slinging oil
I've seen various tools used, like a highlighter pen, to properly install the water pump drive seal. So, if I were to purchase a full front engine gasket set (3 drive seals, 2 water pump gaskets, and a timing cover gasket), that should cover the typical leaks, right? Should I be concerned about the small oil deposits that I found at the front of the throttle body?
Administrator
Joined: Nov 1998
Posts: 71,086
From: Hell was full so they sent me to NJ
Re: Slinging oil
Check the PCV valve to make sure it isn’t plugged up, or that the vacuum line is not missing or damaged.
Courtesy of Shoebox:
http://shbox.com/1/pcv_pipe.jpg
Check for excessive piston ring blowby. That overloads the PCV system, and the pressure build up is relieved be crankcase vapor flowing into the passenger side valve cover, and exiting through the plastic elbow at the rear of the valve cover, into the line that runs to the throttle body. That vapor, often with oil entrained, exits from a hole in the throttle body, in front of the blades. Check the line from the valve cover to the TB for oil buildup. Also, look under the TB top cover for a puddle of oil. With the engine idling, take the oil fill cap off, and listen at the oil fill tube for a “chuffing” sound, indication of possible piston ring blowby.
All these leaks could be caused by excessive pressure buildup in the crankcase, forcing oil through seals and the PCV system.
Courtesy of Shoebox:
http://shbox.com/1/pcv_pipe.jpg
Check for excessive piston ring blowby. That overloads the PCV system, and the pressure build up is relieved be crankcase vapor flowing into the passenger side valve cover, and exiting through the plastic elbow at the rear of the valve cover, into the line that runs to the throttle body. That vapor, often with oil entrained, exits from a hole in the throttle body, in front of the blades. Check the line from the valve cover to the TB for oil buildup. Also, look under the TB top cover for a puddle of oil. With the engine idling, take the oil fill cap off, and listen at the oil fill tube for a “chuffing” sound, indication of possible piston ring blowby.
All these leaks could be caused by excessive pressure buildup in the crankcase, forcing oil through seals and the PCV system.
Registered User
Joined: Jun 2003
Posts: 1,112
Re: Slinging oil
OP
+1 on checking PCV system also. Given the amount of oil you describe it could be from a few places. The WP drive seal is more prone to the others on the TC. Rarely is the TC gasket itself bad and does require dropping the front of the pan to replace...which can then lead to a compromised pan to TC seal so I would hesitate greatly before replacing that gasket.
The WP drive and Opti seals are PTFE seals meaning they must be installed dry (read don't oil them). The crank seal can be oiled but both crank & Opti seals generally don't leak. Since you have to pull Opti to remove/replace WP drive seal than replacing Opti seal is simple
Your serpentine belt and damper can sling oil everywhere making it appear in places the leak is not coming from so IMHO it is best to confirm source of leak before replacing a bunch of seals. Your front intake can be leaking which could present oil under TB or as Fred notes it is purging from your PCV system on hose going into PS of TB
It would be a good idea to clean the front of the motor and then drive to see if you can better determine where leak source is. oil dye kits come in handy here. WP drive seal is hard to determine visually with all the stuff on the motor to see but is a typical "front" engine leak source
The FelPro TC gasket/seal kit will have everything, and more, you need to replace TC gaskets/seals. The "tool" is available on ebay usually for about $20 or you can use a home made version. The coupler itself can be used if cleaned well but the real thing of a "tool" is to have a leading tapered edge so the seal slides on easily so the inner lip does not fold under as if it does you will have a immediate leak
Given the oil you note on front of motor the opti has likely gotten some inside so just clean it carefully when you pull that apart. I have done that a few times. Q tips & TP work well
+1 on checking PCV system also. Given the amount of oil you describe it could be from a few places. The WP drive seal is more prone to the others on the TC. Rarely is the TC gasket itself bad and does require dropping the front of the pan to replace...which can then lead to a compromised pan to TC seal so I would hesitate greatly before replacing that gasket.
The WP drive and Opti seals are PTFE seals meaning they must be installed dry (read don't oil them). The crank seal can be oiled but both crank & Opti seals generally don't leak. Since you have to pull Opti to remove/replace WP drive seal than replacing Opti seal is simple
Your serpentine belt and damper can sling oil everywhere making it appear in places the leak is not coming from so IMHO it is best to confirm source of leak before replacing a bunch of seals. Your front intake can be leaking which could present oil under TB or as Fred notes it is purging from your PCV system on hose going into PS of TB
It would be a good idea to clean the front of the motor and then drive to see if you can better determine where leak source is. oil dye kits come in handy here. WP drive seal is hard to determine visually with all the stuff on the motor to see but is a typical "front" engine leak source
The FelPro TC gasket/seal kit will have everything, and more, you need to replace TC gaskets/seals. The "tool" is available on ebay usually for about $20 or you can use a home made version. The coupler itself can be used if cleaned well but the real thing of a "tool" is to have a leading tapered edge so the seal slides on easily so the inner lip does not fold under as if it does you will have a immediate leak
Given the oil you note on front of motor the opti has likely gotten some inside so just clean it carefully when you pull that apart. I have done that a few times. Q tips & TP work well
Thread
Thread Starter
Forum
Replies
Last Post