[lamans71]

Well at the begining of the summer I had noticed a slight oil leak on the passinger side under the car. But as summer is when I put the car away untill nicer weather I did'nt worry much about it. Well this last week it was finally nice enough to pull her out and start looking into this. after a quick looksee I found that the oil was leaking around the oil filter(you can see the oil pooling ontop of the filter) and running down the filter onto the exhaust. Well I needed to change the oil anyway so I changed the filter and made sure it was well snugged down(yes I did coat the rubber seal prior to install) but alas when I started her up my leak was worse than ever. I ran it for a few miles and then rechecked that the filter was tight, again still leaking. So my question is has anyone experianced a problem with the part that bolts to the block that the filter spins onto? Cracking, warping, other issues that can cause this to leak?

Thanks
Chris

[mechanickeith]

It's possible that there is a problem with the filter mount. Could have a bad gasket between the mount & block. Could have a leaking oil pressure sender & have also seen the filter mount crack from the sender being tightened too tight.

[Greg Reid]

I'm betting on the sending unit. Pretty common spot to leak. Anyway, it's at least very easy to change and it's pretty cheap so it's worth a try.
Best course though to wash it all down and run it for a few minutes...see if you can tell where it's coming from before you spend any money.

[lamans71]

Ok thanks guys, I did make sure the sending unit was snug but it is a cheap part so I'll replace that and see if it makes any change.

Chris

[ta man]

I've replaced a few oil filter mounts that have developed a bit of a warp.

[mechanickeith]

Originally Posted by ta man

I've replaced a few oil filter mounts that have developed a bit of a warp.

I have fix'd a few that were warped & seeping. Used sandpaper on a piece of glass & worked them on the sandpaper till they were flat again.

[Greg Reid]

Originally Posted by lamans71

Ok thanks guys, I did make sure the sending unit was snug but it is a cheap part so I'll replace that and see if it makes any change.

Chris

Not saying that it is for sure the sender but just wanted to point out that when I've had them leak before, it wasn't because they weren't tight enough. They'll leak internally and seep out at the seam or where the plug goes into the body of the sender.
Plus, as stated by others, the housing can leak too...that's why they have a gasket.

[sts]

<that can cause this to leak?>

Yeah

<it was well snugged down>

You would think that a mechanic would know this, but you cannot judge a book by its cover. Also, mecanics aren't known for having an overflow of intellegence.

Have you ever tried installing one correctly?

Start with new filter because your's is trashed if installed it as you describe.

Spin the filter on until the filter touches the seat--that means just touching the oil housing seat. Tighten the filter ONE-HALF TURN. That means 180', shouldn't be that hard to understand, but there I go, thinking again.

Fire it up, and it shouldn't leak, not even a slight seep. Mine is alway bone dry. If you see a seep/leak, tighten it another quarter turn. If you tighten it more than 1/2 to 3/4 turn, it 100% guaranteerd to leak, anwhere from a ever so slight weep to a full blown flood.

If you cannot stand it, thinking it's too loose while looking at a dry lip, let it heat cycle one time, snatch the fliter, and take a feel at just how much effort it takes to remove it.

Or you could follow other mechanical advice; if you do, I wish you the best of luck.

[Pontirag]

leak could be at the mount, dont forget to look at hardware holes too. it could be at the sender where it threads into the filter mount or the plastic could have cracked in the sender causing a leak.

one time a customer came in with a small but steady leak after an oil change.

ended up the rubber o ring from the previous filter stuck to the housing and the mechanic (who me?) did not catch it befor screwing the new filter on.

Dow Corning makes a silicoln grease/lube that you smear a little bit on the o ring it never sticks and as long as you put the filter on hand tight it always comes off by hand.

[lamans71]

Ok so in the past another owner put in a mech oil pressure gage and it was the compression fitting for that was leaking. I put in a plug until I decide which way I'm going to go, use the factory gage or replace the aftermarket one. Thanks to almost everyone who responded for the info and tips.

[psw]

Hello Forum,

Thanks again for solving another one of my frustrating and long-term problems. Thanks to all the authors of this thread and other similar threads here.

My '66 GTO had a bad oil leak that appeared to be coming from the oil pan at the crankshaft seal for about two years. This leak was pretty bad, in that the bottom of the tranny was dripping, the back of the oil pan and the drain plug would have oil drops on it, the bottom of the oil filter would have drops on it and there would be oil on top of the filter, catching in that little lip there. If I cleaned it all up, I noticed that it would not leak again until I drove the car, but I never saw the leak itself with the motor running in the garage, just the deluge after a spirited run on the road.

At great effort (pulling the engine), I replaced the oil pan gasket with one of those very nice one-piece units, added those little steel oil pan brackets, and to my great disappointment did not really see any change. The rear main seal looked good when I had the engine out for the pan gasket replacement, but after the reinstall and the continued leak, I thought I had misjudged the rear main seal and would have to pull the engine again to get the oil leak fixed.

I started scouring the forum again and found this and the other threads on oil leaks associated with the filter housing. I had checked this out pretty good, and did not think that there was a leak from this area, or from the fittings associated with my mechanical oil pressure gauge or its tubing, but I had not actually taken any of these parts off the engine, I had just tried to observe a leak from these with the engine running and the car in the garage. I had even envisioned putting a Go-Pro camera down there to observe this area while driving the car. It turns out a good repop housing is available for quite a bit cheaper than a Go-Pro camera, so I said, why not, give it a try. Bought one and installed it thinking if this works, great, but not really thinking it would solve the problem.

The good news is that yes, this solved the problem! I am still not entirely sure where the leak was coming from. I found no visible cracks on the old filter mount. There were some scratches on the filter sealing surface, but they were pretty minor. There was a small ding on the lip of the old pressure fitting, where the tubing ferrule seats. Both of these things were really the only defects I found, unless there was an invisible crack on the housing that opened up when things got hot and under load. This solved the problem even though I never dreamed that a leak as bad as this, and one I could never see in action with the car running in the garage, could really come from the filter housing area.

Anyway, thanks forum, and if there is anyone out there chasing a leak like I was, consider the filter housing!

PSW

[Ben M.]

Originally Posted by psw

Anyway, thanks forum, and if there is anyone out there chasing a leak like I was, consider the filter housing!

I had one that the housing might still be fine, but somehow the gasket had a rip in it and it looked like it was weeping out (I replaced both). Also had an idiot light sending unit weeping from the crimp on the body recently. There's a lot of places there to leak!

[Txbobcat]

I had a crack in the housing on a chevy. Replaced it and good to go after several fixes.

[psw]

This is a photo-follow up to my earlier post (#11):

The sealing surface for the oil filter:



The little ding on the pressure fitting:



Finally, the housing-to-block sealing surface:


None of these things say "obvious leak" to me but as stated in post #11, replacing these parts fixed my fairly serious oil leak.

PSW

[Harry71GTO]

Where is a good place to buy the oil filter housing and sender/