Do diesels tend loosen up oil filters?

[The motor guy]

This last time I changed my oil I noticed the oil filter could have almost been removed by hand, maybe I didn't have it tightened enough i'm not sure, but I noticed a drop of black oil hanging off the bottom of the filter, and that's the first time I've noticed that EVER on this engine. This is my 6.7 cummins. Usually I tighten as much as I can with my hands then give it another 1/4-1/2 of a turn with the wrench depending on how good of a grip I had and never have issues getting the filter off the next time around. I've been changing the oil in this truck for 12 years now. What I have noticed is inconsistency with how tight they are the next time I go to change them. Sometimes they're good and snug, but in no way was it difficult to remove, then other times i'm like wow that thing was barely tight enough.

 

[BrianF]

I crank mine on by hand as tight as it will go and it stays nice and tight for the full index. No issues yet.

 

[The motor guy]

Btw I'm just a skinny guy so that's why I go the little extra with the wrench cause I know any other guy would have it tighter.

 

[billt460]

I never go by that silly "rule", "Only tighten 1/2 to 3/4 of a turn after the gasket makes contact". That's asking for trouble... On ANY engine. I always oil up the gasket good, then tighten until it feels good and tight. That might be 3/4 turn... Or it might be 1 full turn, or even more. The point being, go by torque. Not by how far it turns.

You wouldn't dare employ that "rule" with your lug nuts or cylinder head bolts. So it only stands to reason, why would you with your oil filter?

 

[Neely97]

My 6.7 never does that.
I have calibrated my arm to the exact torque required.

 

[compratio10_5]

I change oil and filters for my vehicles and those of friends and family and this apparent loosening of oil filters happens on gasoline vehicles too. I often find filters that seem too easy to remove but thankfully have not seen any noticeable oil leaks. But it does motivate me to install the new filters as tight as I can get them by hand. I only use a wrench to tighten a little more if I can not get a good grip on the filter.

 

[JC1]

Do you go off-roading with the truck? Any additional vibrations that could cause the filter to become loose? Maybe you forgot to do that extra tightening step on the last OC......

 

[wings&wheels]

Over the years I've noticed that certain filters' gaskets seem to stick to the filter head more than others. Not so much now that I tend to only use Mann, Hengst or Mahle, they all seem consistent.

Did you use a different filter?

My 2.5NA is a primitive, rough running diesel that doesn't seem to loosen filters, I tighten to the filter's' "tighten to gasket contact + 3/4turn" spec.

 

[Job]

They have thicker base plates, bigger mounting threads, and about the same oil pressure. So they should stay as tight or tighter than lesser filters IMO. Flat gaskets if over tightened go beyond a yield point and the seal is weakened. More tightening becomes less sealing. Go by turns written on the can as that is compression distance, not torque, and the most accurate.

On a 16 thread for example, one turn is about .063 inch. So 1/2-3/4 turn is appx. .031 to .047 inches compression. not very much. I have a hunch you are over tightening and spoiling the gasket with the extra turning. Sometimes it gets by, sometimes not, but it isn't the engine.

 

[xxch4osxx]

I have never had one loosen, but they sometimes seem to get tighter. Never had a filter get loose on the engines on the trucks at work either.

 

[ZeeOSix]

Originally Posted by xxch4osxx
I have never had one loosen, but they sometimes seem to get tighter. Never had a filter get loose on the engines on the trucks at work either.


+1 ... I've never had any oil filter on any vehicle (car, truck, motorcycle) come off easier than it went on.

 

[The motor guy]

I don't really like the fram ultra gaskets. The gasket is almost flush with the metal area on the filter.

 

[geeman789]

Originally Posted by ZeeOSix


+1 ... I've never had any oil filter on any vehicle (car, truck, motorcycle) come off easier than it went on.



Not my experience. MOST of my oil filters seem to self tighten to some extent, needing a wrench to remove after being hand tightened on installation. But more than once, a filter seems to have loosened on its own. I now give the filter a quick twist before any long road trip, just because ... 9 out of 10 won't budge, but a couple have taken a good half turn or more to tighten again.

Gasket over compressed, or a warm filter installed on a cold engine ... who knows ?

 

[ZeeOSix]

Originally Posted by geeman789
Gasket over compressed, or a warm filter installed on a cold engine ... who knows ?


Or maybe a cold filter installed on a warm engine. I always install the filter when the engine is basically room temperature.

 

[CarbonSteel]

I never had that issue on my Ford 6.7L. I would always lube the gasket and tighten as much as I could by hand and was always tight when I removed it.

 

[JohnnyJohnson]

I've been changing filters on two diesel truck over the last 24 years Its never been a issue with either truck. I never do anything but hand tighten my filters.

 

[compratio10_5]

Originally Posted by ZeeOSix
Originally Posted by geeman789
Gasket over compressed, or a warm filter installed on a cold engine ... who knows ?


Or maybe a cold filter installed on a warm engine. I always install the filter when the engine is basically room temperature.


Now that is an idea that I had not considered. What happens to the gasket compression when a cold filter with a hard elastomer gasket is initially compressed against a warm engine block? Then when it is removed both the engine block, the filter and the gasket are at the same temperature (hot). I think that I will start warming up cold filters before they are installed and see if that makes a difference. Thanks for the discussion and ideas.

 

[CR94]

Originally Posted by compratio10_5
... I think that I will start warming up cold filters before they are installed and see if that makes a difference. Thanks for the discussion and ideas.
How 'bout simply checking to be sure it's still tight after the first post-change trip?

 

[geeman789]

For winter oil changes, I always bring the oil and filter inside the house, usually overnight. Warm oil pours easier. However, I wonder if that warm oil filter gasket might shrink slightly after it is installed and allowed to cool down to winter temps, in some cases causing a loose filter ?

Would it better to install a cold oil filter on to a warm engine, and allow the cold gasket to heat and expand slightly, maybe tightening the seal / filter in the process ?

Or are oil filter gaskets sensitive to heat and cold at all ... ?

 

[compratio10_5]

Bringing the oil inside in cold weather is good and I do, but I had not considered the filter. In my mind, I am not so concerned with the elastomer gasket expanding or contracting as I am about softening or hardening (remember the hardened viton o-rings on the space shuttle Challenger at freezing temperature) I am going to experiment by warming the filters in cold weather and see how the gasket responds and as suggested check the tightness after warming the engine. Thanks for the discussion, it seems there is always something to learn.