New oil leak under car. Under passenger side that seems to be around oil pan. Replaced oil sender for second time this week and replaced intake manifold gaskets becauze there was oil all in there from the previous oil sender leak. As far as i can tell there is no oil around the sender this time around, however, the oil pan is pretty well coated with it and it is actually making larger piles of oil than it was before repair. Any and ALL HELP is vastly appreciated. I do not want to lose hope for this car after only 6 months. Oil levels on dipstick still within healthy range. Drove it about 100 miles yesterday after the repair and it drove great.

 

Suggest inspecting the oil pan gaskets. At my yearly C5 '04 maintenance with my go to mechanic, my lower oil pan gasket was found to be leaking and fixed. All is good now.

 

I would suggest to jack up the front (jack stands) and look closely around the Harmonic Balancer, it is very common for the seal on the front cover to leak over time (often earlier on cars that drag race, HPDE, Autocross, etc.) and requires the steering to be removed to replace. Numerous write ups and instruction on the "How To".

 

I will check these both today. If it eas rear main seal gasket wouldnt it be mostly lower on the car ?? And coulf it be pcv valve? What is an obvious sign of rear gasket leak? I will look for harmonic balancer as well thank you.

 

Drip does seem to be coming from lower end of pan. I know this was before becauae of oil sender leak being swept across pan. Could a rear main seal cover entirety of the pan like this??

 

The pictures show where the oil leak is end up on, if it was a rear main leak it would show up on the trans and rear drive shaft, if it is from the front cover seal it will flow to the oil pan at speed. If you had a hard track day, it would accumulate (puddle) under the HB when the car sat for some time

 

based on the pictures what would your best guess be?

 

I have a similar leak on my '99 vert with 153k miles on it. My oil pan looks just like yours plus there is oil on my front spring, mostly on the left side. It appeared to be coming from the front of the engine so I changed the harmonic balancer and front seal. Upon disassembly there was no visible active oil leak at the front seal or balancer but I replaced them anyway due to caked and dry oil/dirt residue on the front cover. I'll keep chasing this leak down and post if I find the real culprit.

 

Get under there with some cardboard and a couple cans of brake clean. Once you clean up that mess, you will be able to see where the leak is comming from.

 

Check your power steering pump and hoses. I had leak on left side and it was power steering pump and a leaky high pressure hose.

 

I to have a C5 '04 which had a similar issue. Lower oil pan gasket was one of my issues, the other was due to modifications on the car.

 

Please Do! And is there any way to inspect the harmoniv balancer and seal for leak without actually removing it? I was to eliminate as much witch hunting work as i possibly can. And on that seal replacement how much did that run you?

 

Well guys, just had a shop take care of my oil leaks on my '03 Coupe with 144K miles on it. JUst a few spots everytime I parked it but being an old mechanic , also too worn out, lack of proper equipment and respect for myy 76 yr old body had them do it. Liked the shop , it's cleanest and attitude of the mechanics. After a week they called me to come get it as it was done and tested. I asked the mechanic where most of the oil was coming from. " Everywhere " was his answer but I pretty much knew that. Pan gaskets, front and rear seals and plate gaskets, valve cover gaskets , new pulley and bolt, cleaned the engine and refreshed the fluids and 2316 bucks later I'm a happy camper.

 

Actually $2300 is pretty reasonable for that amount of work. Just doing rear seal and oil pan gaskets could easily run $2500 alone.

 

I was very happy with the price. 1500 bucks for labor was amazing with all the work. I had brought 2 gallons of Mobil ! oil and told him to keep the what he didn't use for the great work.

 

Thank you for returning to update! I have been checking daily for that haha. I am glad you got it all sorted out and hope you are enjoying your leak free vette. I HOPE mine is not nearly as expensive or as much work as yours, but I have decided that I will pay it regardless because if not WHY ELSE DID THE BUY THE CAR?? I am going to team up with a mechanic friend tomorrow around noon and utilize his lift to find out where this leak is coming from and troubleshoot. I have the UV dye ready as well. He seems to suspect a leaking oil filter or loose pan bolts since it started after a long road trip where there bumpy dirt roads etc. Plus we JUST replaced the oil sender for second time AND the intake manifold gaskets and at that time didn't see any valve gasket issues or any indications of rear main seal leaks. I am praying for the best, but prepared for the worst. Whenever I cringe about the cost basis for getting this up and running again, I just imagine the feeling I get from driving it and it makes it worth while. Ive already put around $1300 into it in first 6 months which is unusual for me as my other vehicles have never ran me over about $250 (outside of regular maintenance) over 3-5 year periods. But for the $1300 I did get :
1) New battery
2) New Brake pads
3) Electrical issue resolved (striped shorting wires re taped and separated. This required the alternator to be replaced twice I troubleshooting but the original was kept since it wasn't issue) 1-3 combined cost: $815.00

4) New oil sender (twice)
5 )Intake manifold gasket replacement
6) PCV valve and tube as well some other vacuum lines replaced. 4-6 combined cost: $535

Does this sound fair?

 

Sounds good to me. Love that you have a friend with a lift to check things out. Wish I would just bought a 2 post lift instead of the quick jacks a few years back. Think I'll put the quick jack set up for sale and get a 2 post lift next year.
And the wife loves that my want for Corvettes has developed enough to finally buy one in the summer of '16 for 5000 bucks, put about another 1000 in it and sold it when I found my present car not far from me in the colors and interior and set up I wanted. Oh yea, sold a 17 foot Nitro boat with a 90 Merc also and bought my '03 Coupe.
But the real reason she was happy is that it cut into my motorcycle time big time. ;-)

 

Added uv dye to the oil and let it idle for a few min at a sloght incline. No leaks no drops at all. I turned off the engine and lowered the car and now there are a few drops in dif spots on the cardboard box but NONE of them have ANY dye in them?! Does this make sense? Any thoughts? Thanks

 

the dye hasn’t worked it’s way through the motor yet. You should probably pressure wash the bottom of the motor and let it dry. Wipe everything clean. And reevaluate for dye after 250 miles of driving.

or your leak isn’t motor oil. It’s steering fluid.

 

i had no idea it took so long for the dye to work through the system!! Power steering fluid is same color but dif consistency right?