Is it true that used up oil ruins seals and gaskets ?

[Yah-Tah-Hey]

"Used up" oil should be discarded at designated sites. I use Walmart but their auto center is not open so will take jerry can of drain oil to our city collection site. Hope someone there will assist 83+10mo dump it.

 

[NewtonPulsifer]

Extra plasticizer might help. 1/3 can/dose of Liqui Moly Oil Saver or ATP AT-205. Normally I just do a run of Valvoline HM but there isn't any 229.5 approved high mileage oils. The 2002 SLK320 very recently got a very light seep at the valve cover gasket, and 1/3 can of Liqui Moly Oil Saver fixed it.

I do 15k miles at 22-23 months per oil and filter change (yes I'm cheap). So 24k kilometers. 60% highway.

EDIT: Along with Archoil 9100 and/or Liqui Moly Ceratec.

 

[Trav]

Good points all and I’ll be happy to address them and this is pretty much across the board as I deal with all of the major manufacturers and this is a routine thing for an in depth lube audit and assessment and I do it frequently for compatibility with lubricants, environmentals and process fluids. Same thing applies to a lot of elastomers used in couplings.

Your question regarding chemical sensitivity is absolutely correct and must be diligently checked but also viewed in context with the whole.

All seals have a chemical tolerance chart by part # (you could DL either the SKF or Garlock manuals or see how deep this goes) and it will tell you pretty much everything. Then there is the engineering service to email for those unique ones.

If exposed to an incompatible fluid, no amount of additives is going to do anything but buy you a short amount of time. There is a very significant difference between a chemical attack against a polymer not rated for it and normal chemical degradation- the trick knows the difference. (It’s seldom obvious unless failure happens very quickly)

Seal analysis involves a battery of visual and physical tests, melt tests, durometer tests and chemical ones to determine failure modes- anyone who doesn’t do all these things is not capable of making an actual diagnosis as tow why a given seal did fail or be able to differentiate between a ‘failure” versus a normal “end of life’ event.

I will tell you who is doing all that testing (some in house- some outsourced)- both the oil companies and the seal companies. Neither one wants to introduce a product with unknown reactions nor neither wants to be on the business end of litigation resulting from such a negligent failure. They cooperate with each other too when asked.

I believe you will find the bulk of these “alleged’ seal failures due to the oil simply aren’t and probably 90% of the remainder that are are a direct result of the individual not doing the proper checking and mismatched them in the first place. ( not really a failure mode or mechanism that one can legitimately assign to the oil or seal as the human is supposed to think and check)

Great post!

 

[tiger862]

I have found heat is the killer of gaskets and seals. If you use a quality oil that does it's job then change according to manufacture the seals will have a happy life. If you over extended oil changes just after the viscosity starts to thicken then the heat of seals increase from oil is at the end of it's usefulness. If the coolant is incorrect for vehicle then other seals start failing pretty quickly. Overheating an engine you almost with certainty your engine will start leaking. Just some of the things I have seen in 30 years of automotive technician.

 

[Deamos]

Good points all and I’ll be happy to address them and this is pretty much across the board as I deal with all of the major manufacturers and this is a routine thing for an in depth lube audit and assessment and I do it frequently for compatibility with lubricants, environmentals and process fluids. Same thing applies to a lot of elastomers used in couplings.

(Snipped to keep the post size down)

This is an awesome post, thank you for taking the time to share your knowledge.

 

[buster]

Changes for GF-7

"Concerns around seal compatibility mean that seal test changes are also likely for the new specification, with upcoming decisions on whether to keep and/or replace ASTM D7216 – Standard Test Method for Determining Automotive Engine Oil Compatibility with Typical Seal Elastomer. Deegan noted the potential use of the SAE J2979 Compression Stress Relaxation (CSR) test which, he says, OEMs have used to reduce warranties. He also underlined a need to add new seal materials from hydrogenating acrylonitrile butadiene rubber (HNBR), fluro-elastomer (FKM-3), and polyacrylate rubber (ACM-2, AEM-2, AEM-3). In high volumes, ACM is an affordable alternative to HNBR and FKM seals."

 

[nomas]

Louis Altazan of Agco Automotive in Baton Rouge says they are seeing so many more engine repairs since car manufacturers started
increasing the OCI. Many more leaks. He says with the 3k-5K OCI it was very rare to see a car needing engine repairs.

I generally agree with him but I'm not buying this one . I don't think it's all about OCI's .