Drove the Vette to work and wouldn't you know, it still has a small leak. Seems I've made some progress but it's still not sealing completely. I would like to try a slightly thicker O-ring but not sure where to find one. We had a nice Parker O-ring assortment kit at my old job but no longer have access to it.

 

You can buy an assoment of o-rings from Summit for $10.00.
http://www.summitracing.com/parts/tt...FQPhQgodYRIAAQ
Or call Parker and see if they will send you a sample of what you are looking for. You will have to send it to your work address.

 

I believe the o-ring is a dash 113

Can you measure the inner diameter for us?

http://www.rocketseals.com/catalog/o...e-chart%3B8215

http://www.allorings.com/size_cross_...nce_framed.htm

http://www.grainger.com/product/O-Ring-1KFL1

 

I can measure the old O-ring, but it will have to be tomorrow or Sun. Thinking I should probably also measure the outside diameter of the sensor where the O-ring goes and order one that would be a snug fit. I'm assuming the buna-n material would be the best, but I'm not 100% sure abt that. There may something better out there I'm not aware of.

Another thought was to put something on the factory o-ring that would swell it slightly. Something like eng oil "stop leak". I'd never pour that stuff in my eng oil, but smearing a little on one troublesome O-ring might be worth a shot.

 

Got out to the shop today and measured the O-ring from my old cam sensor.

ID= ~ 0.566"
Thickness= 0.102"

Diameter of the cam sensor where the O-ring sits= 0.571

It does appear it is a -113.

Looks like a -207 is the next step up, but may be a bit hard to install.

A 14mm X 3mm might work even better.

 

Thx for the links Got uid0!

Contacted Rocket Seals today.
Got a variety of O-rings coming to try.

Ordered some 14mm X 3mm buna -n 70-durometer. They have a slightly thicker cross section than the factory -113's (2.62mm cross-section) and they are my main hope. Tried to get some with 50 durometer stiffness (softer), but they couldn't locate them on the shelf.

If that fails, got some -113 silicone o-rings coming too. I know they will swell slightly when exposed to eng oil.

If they both fail, got a -113 quad-ring to try.

Hopefully one of them will work.

 

following along with my own oil leak.

Good luck

 

No problem I need to fix mine too so let me know if a diff ring will work a bit better.

 

It's hard to believe the original O ring would not seal unless there's an issue with the sealing surface down inside the block. But how the H... could that get damaged down inside there. Very odd.

 

I belong to another forum, and posted a thread asking for help with this exact problem. Got no response. Did a Google search, and found this thread. I joined this forum specifically to say "THANK YOU!!!" for providing the information I so desperately needed. The photos are a tremendous help.

I was getting ready to pull the whole drivetrain out to get at the rear main seal of my 2000 Vette. It has 140K miles and is my daily driver. I will absolutely check the cam sensor O-ring before I do anything else. I have already replaced the oil pressure sensor about a year ago, but will give it a close inspection. I will continue to monitor this thread to see how it all turns out. ZZ28ZZ, I wish you the best of luck in getting that stubborn leak repaired.

I posted a link to this thread on the other forum, so that anyone having the same issue could come here and perhaps avoid unnecessary work and expense. If that is a problem, I will gladly remove the link from that forum.

Thanks again,
thundertruck

 

I don't have a problem linking the thread. Ultimately, I suppose that's up to the moderators.

I've received a tremendous amount of highly detailed and accurate info from this site. It's saved me thousands of dollars repairing my 2000 Vette.
I'm just happy to be able to give a little something back.

I'll be pulling the intake again tomorrow to try again.

 

I had been doing a lot of research on my suspected cam sensor being the culprit and i did not want to have to purchase a new cam sensor so that is how i stumbled across the O-ring information.

How many of you have a 2000 with this suspected failure point?

How many of you are using a Oil Catch Can with this suspected failure point?

zz28zz after the first replacement did you happen to siphon out the oil after removing the sensor?

 

No catch can here. I did replace the PCV valve, no help.

I did clean out the "chamber" just above where the O-ring is supposed to seal.
Reference post #14.
I've done that every time before I install the cam sensor.
Every time I remove the cam sensor, there's a new puddle of oil in the chamber.

Got uid0, is your Vette a 2000 model also?

 

The bad luck continues.
Found the packaging for my new seals scattered across the front yard. Apparently someones dog hates yellow envelopes sitting on my porch.

All I could find was the silicone -113 O-rings. The slightly oversized buna-n and the quad ring are nowhere to be found.

I placed a new silicone O-ring on top of my original cam sensor O-ring and they look identical (except the silicone is orange).

Pulled intake and cam sensor. Sensor was wet above the O-ring, so I know it was still leaking. Installed the modified cam sensor (ref post 14) to plug the hole leading to cam and washed out chamber again with solvent and dried.

Took one of the silicone o-rings and submerged it in eng oil. Went to parts store to get more intake gaskets. When I returned, I removed the silicone o-ring and compared it to another new silicone o-ring. It does not appear to have swollen, but it was only exposed to eng oil for abt 30 mins.

I re-installed the cam sensor with the silicone O-ring I had been soaking in eng oil.

Was just abt to re-install the intake and noticed the rubber coupler that connects the valve cover breather tubes with the PCV hose looked like it was folding over on itself. Hard to tell how much restriction it was causing but was surely causing some restriction.

Used an old 3/8" vacuum Tee I found in the tool box along with some 3/8 fuel line to replace the collapsed coupler.

Everything back together and bottom side cleaned up again. Not seeing any leaks, but I've been fooled before. I'll take it for a spin tomorrow and report back.

BTW, Rocket Seals charged me $18 for S&H for 7 O-rings. Damn! Really?!?

 

yes 150k

 

ZZ28ZZ, Some guys have all the luck... Then again, maybe the dog made the right choice for you. If not, you could always go looking for Labrador O-rings. (re Tommy Chong, "Up in Smoke")

It is possible that the restricted PCV line may have been causing excessive crankcase back pressure, and at least contributing to the oil leak problem. The PCV system causes the engine crankcase to run in a slight negative pressure, which should help keep the oil inside. On mine I found the elbow on the PCV line on the passenger's side at the rear of the head had split open. There was an accumulation of oily gunk there from the escaping vapors. I replaced it with a 3/8" vacuum line elbow. It did not stop the oil leak, but seems to have slowed it down a bit.

How long did it take you to replace the sensor O-ring? I was going to wait until the weekend to pull mine out. I need the car to go to work, but if it can be done in a couple hours, I may do it sooner.

It is hard to tell from the last picture, but it looks like there might be enough room in the O-ring groove to put a backer O-ring in there with the original one. The kind I am talking about is the hard plastic (PTFE) split ring . They are used in automatic transmissions as shaft seals, and in some diesel engines on the HEUI type injectors. Here is a link to one that might work.

http://www.grainger.com/product/O-Ri...OAPD&pbi=1KFL1

It would take up some of the slack in the groove, and force the O-ring tighter against the bore in the block.

Good Luck. and Keep us posted. I've gotta see how this ends.
thundertruck

 

I've been following this thread and am quite baffled at what you're experiencing. It doesn't make sense to me that a brand new sensor would leak. I have to ask; did you use an OEM or aftermarket sensor? You don't say in your posts. Is it snug when you slip it in place? Is it possible that the replacement sensor is slightly undersized?
I've never heard of someone having to change the o-ring on a new sensor because of a bad seal.

 

I have had a small leak on the passenger side from when my Z06 was new, which I think is coming from right in the back corner where the upper oil pan mates with the block... above where you photo points out.
It seems to be not so bad when the oil level is a little lower, so I have not bothered to fix it.

 

New cam sensor was bought at the Chevy dealership. $106!!

It does feel a little snug when installed. Once I feel the O-ring enter the hole, it goes down abt a 1/2" more..

 

Thunderstruck:
That's exactly what I was thinking when I saw the collapsed PCV line coupler (excessive crankcase press). The rubber PCV connector on the pass side valve cover near firewall was split on mine too. Used a piece of 3/8 hose to make another coupler. After I got everything back together and started eng, I pulled the hose off where the fresh/filtered air enters pass-side valve cover. Placed my finger over the nipple to see if I could feel any suction. I didn't feel any suction but I did hear a whistling sound when I removed my finger, so it seems to sucking in air OK.

I timed myself the last time I pulled the intake. Took 13 mins and I didn't have any tools staged. However I've done it at least 6 times over the last 4 weeks or so.

The sensor is a piece of cake once the intake is off. 1 elec connector and 1 bolt (10mm).

What slowed me down was the intake gaskets. I replaced them all the first time I removed the intake. Didn't use any sealant, just popped the new seals into the grooves (after cleaning with brake cleaner) and re-installed intake. The next few times I removed the intake, at least 1 of the seals would pop out of the groove. Once they get oily, they swell a bit and they don't wanna stay in the grooves. Had to clean the seal and groove with brake cleaner and apply sealant to hold them in. The last time I pulled the intake, I bought a new set of intake gaskets and just replaced the ones that wouldn't stay in their grooves. Soo, If I was you, I would buy a new set of intake gaskets and a can of brake cleaner. Oh yeah, don't forget to make a couple of split vacuum hose spacers for the rear intake bolts like prev mentioned in this thread.

Not sure if a O-ring backer would help or not. I discussed that with the sales rep at Rocket Seals and decided not to try it since there's no press to speak of.

I'm really starting to wonder if it is the O-ring that's actually leaking.
The top of the rear cover is really close to where the cam sensor cavity opens to the rear of the block.

Another thought is maybe the block has a porousity issue near the cam sensor.

One more thing I can try is to remove the cam sensor and install the "plug" I made (ref post#14) from my old cam sensor. Re-install the intake, snake my remote camera back into the cam sensor hole, start eng and see if I can tell exactly where the oil is coming from. It will be a real PITA, but may be the only way to tell for sure.

I understand the eng will run without the cam sensor, but may need to crank a few extra revolutions before the crank sensor figures out what stroke the cyls are on.

BTW, went for a quick drive the auto parts store to pick some brake pads for my daughters car. I didn't smell anything coming thru the vents, but did see a small puddle where I parked. Praying it was someones else's puddle, but it probably wasn't.