1MZ-FE oil leak around filter seal, help!

[AlexLemond]

Hi everybody---new guy here with a problem that I couldn't find by searching the forum (although there's lots of other great stuff here...). I have had a 2002 Camry with the 3.0 V6 (1MZ-FE) for a few months, and just changed the oil for the first time. I'm no stranger to oil changes, having done them myself for many years on a variety of cars. Never had a problem with it before. But no matter what I do I cannot get the filter on the Camry to seat right and seal. It leaks from the driver's side of the filter and drips straight down onto the exhaust (and smells just lovely). The leak is such that before I realized what was happening, the car was leaving a quart a week on the ground.

I've tried a couple different filters, thinking I maybe had some defective ones with a bad seal. But I get exactly the same results with both OEM Denso filters (the blue ones) and factory ones from a Toyota dealer.

I am quite sure that I did not leave the old filter gasket on the engine before putting the new filter on. The only thing I can think of is that maybe I am consistently overtightening the filter. I've never had a car that was fussy about that before, so I'm usually pretty casual about it---just follow the rule of "turn it by hand until you feel the gasket hit the block, then give it a turn with the wrench." But the filter on this car is so hard to reach from below that I was pretty much doing it by feel. (I only just discovered that you can do it from above if you remove the upper shield from around the exhaust manifold---that was how I got a clear enough view of that side of the block to be sure where the oil was coming out.)

Thanks for any help or suggestions anyone can give. I am really scratching my head over this one---it is pretty frustrating to be stuck on something so basic!

[gdanaher]

This is almost always the result of having an old seal stuck in there, so even though you have checked, check again, thoroughly, using a good light and a mirror if needed to look at it. Second, the Toyota filters use a sort of o-ring seal. Try a Fram that uses a squared seal. Beyond that, take it to the dealer for another oil change and see if they can get it to not leak.

[AlexLemond]

I'm not a big fan of Fram---prefer Purolator at the low end, Wix at the high end (for most cars that I care about), and usually Denso for Japanese cars---but I see what you mean about the gasket shape. Now that I have the heat shield off I have a better view of the mounting surface, so I'll take the filter off and take a closer look at it to see if I left the old gasket on there as you suggest.

Any other possibilities, if I do have the right number of gaskets? I had a wild idea that maybe the leak could be caused by the wrong weight oil, if it's too thin when hot for the filter gasket to hold in. I was using Mobil1 synthetic 0W30, but when the leak started and I began messing around with different filters I switched to Valvoline conventional 5W30, not wanting the Mobil1 to be going down the drain, so to speak, at $7 a quart. Another possibility that occurred to me, if I cross-threaded the filter from below when I couldn't get a good view or grip on it, could I have damaged the threads on the block? If so does the threaded unit come out as with some engines or would the threads need to be cleaned up with a special die? I'm just brainstorming here since this situation is so baffling to me.

[JohnGD]

Also, if you don't mind using a larger filter, Motorcraft FL400S at Walmart should do. Or Purolator PL20195. After gasket contact an additional 3/4-1 turn. I'm not a fan of Denso filters.

Originally Posted by AlexLemond

Hi everybody---new guy here with a problem that I couldn't find by searching the forum (although there's lots of other great stuff here...). I have had a 2002 Camry with the 3.0 V6 (1MZ-FE) for a few months, and just changed the oil for the first time. I'm no stranger to oil changes, having done them myself for many years on a variety of cars. Never had a problem with it before. But no matter what I do I cannot get the filter on the Camry to seat right and seal. It leaks from the driver's side of the filter and drips straight down onto the exhaust (and smells just lovely). The leak is such that before I realized what was happening, the car was leaving a quart a week on the ground.

I've tried a couple different filters, thinking I maybe had some defective ones with a bad seal. But I get exactly the same results with both OEM Denso filters (the blue ones) and factory ones from a Toyota dealer.

I am quite sure that I did not leave the old filter gasket on the engine before putting the new filter on. The only thing I can think of is that maybe I am consistently overtightening the filter. I've never had a car that was fussy about that before, so I'm usually pretty casual about it---just follow the rule of "turn it by hand until you feel the gasket hit the block, then give it a turn with the wrench." But the filter on this car is so hard to reach from below that I was pretty much doing it by feel. (I only just discovered that you can do it from above if you remove the upper shield from around the exhaust manifold---that was how I got a clear enough view of that side of the block to be sure where the oil was coming out.)

Thanks for any help or suggestions anyone can give. I am really scratching my head over this one---it is pretty frustrating to be stuck on something so basic!

[AlexLemond]

Still leaking oil, still going crazy!

I have tried three different kinds of filters now---Toyota OE, Denso which looks exactly the same as the Toyota one except for the color, and a Wix filter from NAPA that is larger and has a seal that is square in cross-section instead of round (that is, with a wide, flat sealing surface). Have tried a couiple of each, tightening them different amounts in case I am over/under-tightening the filter. No matter what I do, I get the same leak from the low side of the filter where the seal contacts the block.

I was able to reduce the leak to a very slow ooze, not even a trickle, with the Wix filter, tightened much less than I would normally have done it--- I turned it until the seal BARELY contacted the block and then hand-tightened it 1/2 turn beyond that. It could have gone a lot farther had I used the wrench, but it was just barely past snug doing it by hand---I'd guesstimate I put about 10 ft/lb of torque on it at the very most. But that little ooze is not really satisfying, because I'm quite sure there was no leakage whatsoever with the filter that was on the car when I bought it, before I entered my own private Oil Change Hell. (Of course I didn't save that filter so I could see what kind it was---maybe it was the only kind that will seal right! I haven't tried a Fram yet as suggested.)

I'm absolutely sure that a previous filter's seal is not still on the block. The threads that the filter screws on to are clean and I'm not cross-threading it. The sealing surface on the block is clean and smooth---I even polished it with a light oil and bronze wool, then cleaned it with brake cleaner followed by compressed air.

Help! What is going on here? I can't possibly be the first person to have had this problem, can I?

[csaxon]

Was the original filter you removed a toyota filter and did you replace it with the same filter?
Check the union (the threaded piece the filter screws onto) and tighten it up. It may have unthreaded enough to prevent sealing when you took the filter off.

[Yazovets]

I had a leak around the filter seal once, too and my mechanic found out that some round seal in fact had cracked/ripper. Once he replaced it, the problem never returned.

[JohnGD]

That's a great suggestion. You may need a hex socket to tighten it.

http://www.harborfreight.com/cpi/cta...emnumber=98229

Originally Posted by csaxon

Check the union (the threaded piece the filter screws onto) and tighten it up. It may have unthreaded enough to prevent sealing when you took the filter off.

[AlexLemond]

Well, turned out I had two separate issues. One is a slow oil leak from either the valve cover gasket (no big deal) or the head gasket (, but at least it's on the front cylinder bank), dripping down onto the exhaust manifold.

The other was, as I originally suspected, fussy oil filters. At no point did I accidentally double up filter gaskets, and the mounting boss was always good and tight. Through the process of trying a few different filters and varying my tightening technique, I finally worked out, by trial and error, that the official white Toyota filters and the identical Denso OEM item work the best, and that exactly one turn with the filter wrench after the gasket barely contacts the block gets them just right---not too tight, not too loose. No leakage from the filter now, after 3K+ mi.

I am still really surprised that nobody else here has encountered this problem. Like I said in my first post, I've never seen another engine that was so sensitive to the filter being tightened "just right" a la Goldilocks. I have a theory that the leakage I was seeing happens because the filter is right next to the first-stage catalytic converter on the radiator side of cylinder bank 2, which gets really hot. The block is a better heat sink than the filter, so the two expand and contract at different rates with overall changes in engine temperature. The seal can't handle all this expansion and contraction, and ends up leaking. It's similar to the phenomenon by which engines with iron blocks and aluminum heads often develop head gasket leaks, because the two metals expand at different rates as the engine heats up to operating temperature. (I'm looking at you, Mercedes OM603...)

I consider this a serious (and easily avoidable) design flaw on Toyota's part. There's no reason for the oil filter to be located where it is, in basically the hottest place under the hood. For that matter, there's no reason for catalytic converters to be located under the hood! Lots of carmakers tried that in the early days of emissions controls (the late '70s and early '80s) and quickly found that the problem of dealing with waste heat from the cats more than offset the emissions benefit of having them as close as possible to the exhaust valves. Cats belong under the car, farther down in the exhaust system, where the airflow under the car can cool them and keep them from cooking the engine and passengers.

[zythr]

As good a carmaker as Toyota is, they do make mistakes, even deeign oriented ones.

[JohnGD]

The oil filter mounting union is tightened to the block using a hex socket. If this came loose then you can experience oil leaks. So the next time you remove the filter, try tightening the center tube mounting union with a hex socket. See if it's loose.

Originally Posted by AlexLemond

The other was, as I originally suspected, fussy oil filters. At no point did I accidentally double up filter gaskets, and the mounting boss was always good and tight. Through the process of trying a few different filters and varying my tightening technique, I finally worked out, by trial and error, that the official white Toyota filters and the identical Denso OEM item work the best, and that exactly one turn with the filter wrench after the gasket barely contacts the block gets them just right---not too tight, not too loose. No leakage from the filter now, after 3K+ mi.

[AlexLemond]

Originally Posted by JohnGD

The oil filter mounting union is tightened to the block using a hex socket. If this came loose then you can experience oil leaks. So the next time you remove the filter, try tightening the center tube mounting union with a hex socket. See if it's loose.

Nope, it was always plenty tight. I did remove it hoping to find a deteriorated o-ring, but there was no room for one.

It was definitely the oil filter seal... there's just nohing else it could have been. After figuring out that the car only likes OE or OEM filters and is very fussy about the tightening procedure, I'm not getting any oil at all around the edge of the filter.

[PRINCESS PEACH]

when tightening the oil filter, should you not tighten it all the way?

[RickF]

Originally Posted by PRINCESS PEACH

when tightening the oil filter, should you not tighten it all the way?

I've always heard that the oil-filter wrench IS ONLY for loosening the filter - not tightening it. Isn't it true to only hand tighten?

Glad to read you got your leak stopped.

[AlexLemond]

Originally Posted by PRINCESS PEACH

when tightening the oil filter, should you not tighten it all the way?

Depends. "All the way" is way too vague, unfortunately---it would change depending on how strong you are, what kind of filter wrench you have, etc.

IIRC it says on the Denso and Toyota filters to tighten them 3/4 turn after contact with the block (as on many filters for other cars), but as I wrote a couple of messages back, I found that 1 full turn, no more, no less, was the way to get it to stop leaking.

"Contact with the block" is more complicated than it sounds, too---you have to develop a feel for it. When you start the filter, turn it slowly down the mounting shaft by hand. It should go on at first very easily, unless you have cross-threaded it (in which case back off immediately before you ruin the mounting boss.) Wait for the resistance to increase gradually---that's the gasket hitting the block and starting to compress. Just at the start of that increased resistance is where you want to start measuring the full turn (or 3/4 turn, or whatever). Hint: watch the printing on the filter, or put a dot on it with a Sharpie and watch for it to come around again as you turn it.

No matter what, you DON'T want to tighten the filter as hard as you can---that will almost certainly crush the gasket and press the metal filter shell hard against the block, resulting in major leakage.