I've got some leaks
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Joined: Jun 2012
Posts: 90
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From: The Villages, Florida
I've got some leaks
4 year c5 z06 owner here. I've got leaks from the front of the motor. I see drops coming down from the tip below the oil drain bolt. I Took it to a Corvette Mechanic in Orlando and I'm told that the front seal is leaking, along with the upper oil pan gasket. Some wobble from the harmonic balancer which, I understand would be taken care with the front seal replacement. The oil pressure sending unit wasn't mentioned, so I'm assuming no oil is coming from there.
I was also told the clutch slave cylinder is leaking, and I would have the rear seals replaced as well, along with a clutch potentially. I bought the car with 62k miles, and I don't know if the clutch is original. It totals up to about $4,500 in repairs (without an new clutch).
This isn't my first rodeo with a C5, I love the car, and I want this car to take me into my 70's...in short, repair cost be damned I'm keeping the car.
About the upper oil pan gasket...should I ask to have the bolts retorqued?
Another question I have is what could have caused the sudden engine oil leaks from potentially two locations? Should I investigate the PCV system? I also have an oil catch can...any potential for problems there?
Car has about 90k miles.
The car has Kooks headers, and a vararam CAI.
I was also told the clutch slave cylinder is leaking, and I would have the rear seals replaced as well, along with a clutch potentially. I bought the car with 62k miles, and I don't know if the clutch is original. It totals up to about $4,500 in repairs (without an new clutch).
This isn't my first rodeo with a C5, I love the car, and I want this car to take me into my 70's...in short, repair cost be damned I'm keeping the car.
About the upper oil pan gasket...should I ask to have the bolts retorqued?
Another question I have is what could have caused the sudden engine oil leaks from potentially two locations? Should I investigate the PCV system? I also have an oil catch can...any potential for problems there?
Car has about 90k miles.
The car has Kooks headers, and a vararam CAI.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
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From: Cape Coral, Florida
Yes, a clogged PCV valve may cause crankcase pressure to increase and cause oil leaks...take a look at your oil dipstick tube....is it popped out ??...that may be a symptom !!
Racer
Joined: Feb 2006
Posts: 489
Likes: 7
From: EUSTIS FL
I just did my front seal along with are new harmonic balancer these cars are getting old mine was pretty bad also the high pressure steering line gets over looked for leaks . The oil pressure sensor pegged so i did that too it was also leaking on the back side of the block .
Pro
Joined: Nov 2018
Posts: 674
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Unless there is excessive pressure in the crankcase or the bolts loosen up the pan gasket usually wont leak, the front and rear main will leak. I would have them check the torque on the pan bolts.
The wobbling harmonic balancer would be the issue that would knock out the front seal
after 90 k miles the pan bolts will loosen up
The wobbling harmonic balancer would be the issue that would knock out the front seal
after 90 k miles the pan bolts will loosen up
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Joined: Apr 2019
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Is the oil pan gasket issue an age thing or a mileage thing? I've had my C6 for 6 days. It's an '06 with 28,500 on the odo.....after a bit of a fiasco, my dealer is replacing the harmonic balancer at no cost to me since the symptoms started 2 days after I brought it home. Just talked to the Chevy dealer that will be doing the work next week and he noted that the oil pan gasket on these is a maintenance issue and that, while they have the car apart, they can replace the gasket for the bargain price of $800 instead of $1700 down the road.
The car doesn't leak and I am most likely going to pass on the offer (I've lived with an '84 that has leaked a bit of tranny fluid since 1999). So, I am wondering if the oil pan gasket (condition unknown right now) failure problem is more as the result of age or the result of how many miles are on the car. Thanks!
The car doesn't leak and I am most likely going to pass on the offer (I've lived with an '84 that has leaked a bit of tranny fluid since 1999). So, I am wondering if the oil pan gasket (condition unknown right now) failure problem is more as the result of age or the result of how many miles are on the car. Thanks!
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Joined: Dec 1999
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The upper pan gasket can usually be resolved by retorquing the bolts. NOTE!!! The threads of the bolts will be contaminated with engine oil. If you retorque to factory specs, you could end up stripping some of them out. especially the LONG ones at the back of the oil pan.
Clean the bottom side of the engine well and tighten up the pan bolts and see if that resolves the upper pan leak.
The front cover dampener seal is a well known issue. The seal gets hard and damages the sealing surface on the dampener snout. It cuts a groove into it and leaks like a sieve. If you have someone service it, have them replace it with a DAYCO/POWERBOND dampener.
Make SURE that they know the CORRECT procedure on installing and properly torqueing the OEM dampener bolt. IMHO, I use an aftermarket ARP Dampener bolt!
On higher mileage engines, its a good idea to replace the timing chain while the front cover is off.
Bill
Clean the bottom side of the engine well and tighten up the pan bolts and see if that resolves the upper pan leak.
The front cover dampener seal is a well known issue. The seal gets hard and damages the sealing surface on the dampener snout. It cuts a groove into it and leaks like a sieve. If you have someone service it, have them replace it with a DAYCO/POWERBOND dampener.
Make SURE that they know the CORRECT procedure on installing and properly torqueing the OEM dampener bolt. IMHO, I use an aftermarket ARP Dampener bolt!
On higher mileage engines, its a good idea to replace the timing chain while the front cover is off.
Bill
