Can seal conditioners damage an engine?

[hunter2929]

Can they damage an engine? I have a 40 year old car with 15k original miles. It has a small crank leak.

Was thinking of giving a high mileage oil a try.

Opinions please, thanks

 

[maraakate]

They'll be too dried out for any kind of conditioner or stop leak to help. You'll need to replace the seals. Low mileage and vintage almost always means leaky seals. I'd rather have a higher mileage engine for a vintage car that had good services records over a very low mileage engine for this exact reason.

 

[kschachn]

Can they damage an engine? I have a 40 year old car with 15k original miles. It has a small crank leak.

Was thinking of giving a high mileage oil a try.

Opinions please, thanks

They have an API license, do you think the API would allow a licensed oil to damage an engine?

 

[hunter2929]

Why not, the FDA allows HFCS to damage millions of people.

When I say damage I mean can it make a leak worse in the long run, how many times can you swell a seal or keep it swelled. Something along those lines is what Im getting at.

 

[spackard]

One recommended on here is AT-205. I used it. It seemed to help for about 5 years then the leak came back, and seal replacement fixed it.

 

[JavierH19]

High mileage oils aren't aggressive compared to additives so give it a try. i've never heard of a high mileage oil damaging seals/gaskets only the additive bottles or a combination. Use pennzoil high mileage 10w-40. HD sells it locally. Valvoline maxlife is a good option too available at walmart.

 

[Lubener]

Can they damage an engine? I have a 40 year old car with 15k original miles. It has a small crank leak.

Was thinking of giving a high mileage oil a try.

Opinions please, thanks

I doubt High Mileage oil is going to recondition a leaky 40 year old seal for the long term. It will take several change intervals to see if High Mileage oil will work. I doubt it will make it worse and it's worth a try.

 

[billt460]

My 1991 F-150 developed a rear main oil leak about 20+ years ago. It's not a heavy leak, so I bought a couple of those big drip pans, and just lived with it. A few years back, (maybe a bit longer than that), I switched from regular Mobil 1 10w40, to High Mileage Mobil 1 of the same weight.

I can say it has greatly reduced the leak. It has not eliminated it. But it most definitely leaks far less than it did before. So I'll continue to use the product. Since then I have read that it's not a bad idea to use these type of oils if you have a newer vehicle that gets low mileage due to infrequent use.

This i'm not sure about, so I'm hesitant to try it in my newer vehicles that get driven very little. Besides, neither one of them leak a drop. But I would like to keep the seals properly conditioned so they don't start leaking.

 

[OilStainedNapkin]

Why not, the FDA allows HFCS to damage millions of people.

When I say damage I mean can it make a leak worse in the long run, how many times can you swell a seal or keep it swelled. Something along those lines is what Im getting at.

Lol wow

 

[NibbanaBanana]

My 1991 F-150 developed a rear main oil leak about 20+ years ago. It's not a heavy leak, so I bought a couple of those big drip pans, and just lived with it. A few years back, (maybe a bit longer than that), I switched from regular Mobil 1 10w40, to High Mileage Mobil 1 of the same weight.

I can say it has greatly reduced the leak. It has not eliminated it. But it most definitely leaks far less than it did before. So I'll continue to use the product. Since then I have read that it's not a bad idea to use these type of oils if you have a newer vehicle that gets low mileage due to infrequent use.

This i'm not sure about, so I'm hesitant to try it in my newer vehicles that get driven very little. Besides, neither one of them leak a drop. But I would like to keep the seals properly conditioned so they don't start leaking.

I worry about that too. I have a lot of vehicles and don't put many miles on any of them any more. Sometimes I won't get a chance to drive one for over a month but I try to keep it to that as a worst case scenario. I don't think I ever change oil more frequently than once a year any more. And usually more like every 2 or 3 years. Just can't find a good reason to dump out perfectly good Mobil 1 with only 1500 miles on it. Haven't ever gotten anything but high mileage out of engines despite this "neglect". Never, ever have had a lubrication related issue. Most of my vehicles go 7500 mile OCI and never do I add a drop of oil between changes in the engines I have had from new. I don't use the water thin, dinosaur wizz oils though. Almost exclusively good old Mobil 1 5w-30.

New Mitsubishi Mirage with it's tiny 3 quart sump will not go 7500 mile OCI's nor will new Toyota Tacoma with it's 2.4L turbo go 10,000 mile OCI's.

I've never read anything on any label of high mileage oil that would indicate that you couldn't use it in a new engine.

 

[billt460]

I worry about that too. I have a lot of vehicles and don't put many miles on any of them any more. Sometimes I won't get a chance to drive one for over a month but I try to keep it to that as a worst case scenario. I don't think I ever change oil more frequently than once a year any more. And usually more like every 2 or 3 years. Just can't find a good reason to dump out perfectly good Mobil 1 with only 1500 miles on it. Haven't ever gotten anything but high mileage out of engines despite this "neglect". Never, ever have had a lubrication related issue. Most of my vehicles go 7500 mile OCI and never do I add a drop of oil between changes in the engines I have had from new. I don't use the water thin, dinosaur wizz oils though. Almost exclusively good old Mobil 1 5w-30.

New Mitsubishi Mirage with it's tiny 3 quart sump will not go 7500 mile OCI's nor will new Toyota Tacoma with it's 2.4L turbo go 10,000 mile OCI's.

I've never read anything on any label of high mileage oil that would indicate that you couldn't use it in a new engine.

I have gone to once a year oil and filter changes as well. I just did all 3 vehicles earlier this week. I also could have gone longer, but once a year works for me. I like doing all 3, one after the other. That way I only have to drag out all the tools and ramps once.

I have a big 5 gallon plastic container all the old oil fits in. So after I'm done I run it over to Autozone and they dump it for me. I try never letting a vehicle sit for more than a week. And when I do run it, I do it long enough to get everything up to operating temperature.

 

[hunter2929]

Thanks guys!! It's a small leak so maybe I'll get lucky, worth a try.

 

[SC Maintenance]

What oil are you currently running - synthetic or conventional?

I have no idea how much extra seal conditioner is in the the High Mileage oils - anyone know? I doubt it would hurt, also doubt it would help. I would probably just run conventional if your not already. That is what those seals were designed for, and there a natural seal sweller.

 

[hunter2929]

I was running 5w30 full syn. I think that was a mistake as it took 2000 miles to start leaking over five years.

This is a 1986 car, I was going to run a High Mileage synthetic blend 10w30 thinking it is mostly conventional oil.

It that a reasonable choice or should I just run 10w30 conventional?

It's a summer car only.

 

[GMBoy]

I am not a fan of stop leak products however I will say that BLUE DEVIL products are safe and work. They have an oil stop leak and a rear main seal stop leak. They work by conditioning the seals to attempt to make them softer and pliable to seal again vs swelling them up. We always offer this option 1st for our customers with rear main seal leaks because that repair is expensive and worth the $20 risk to try a stop leak. Blue Devil has a 80% success rate in our experience. It stops many leaks and slows down the larger leaks enough that it's bearable. I would, in your case, try the REAR MAIN seal product. Be sure to wash off all the oil mess well so you can verify the product is working.

 

[hunter2929]

Mine is leaking at the balancer , does that matter?

 

[PWMDMD]

Why not, the FDA allows HFCS to damage millions of people.

When I say damage I mean can it make a leak worse in the long run, how many times can you swell a seal or keep it swelled. Something along those lines is what Im getting at.

Fun fact...sucrose (table sugar) is a disaccharide composed of 50% glucose and 50% fructose. HFCS comes in both a 42% and 55% fructose versions with the rest of it being made of water and glucose - so same components make up both but HFCS is a mixture of two monosaccharides while sucrose is a disaccharide made of the same monosaccharides as HFCS. Sucrose and HFCS have the same sugars with just slightly different ratios. The first part of carbohydrate digestion happens in the small intestine where a disaccharidase (Sucrase) splits sucrose into individual glucose and fructose molecules and they get absorbed. When you eat HFCS, you simply skip the disaccharidase and it get's absorbed. What I'm saying is fundamentally, outside of a slightly different ratio of glucose to fructose, table sugar and HFCS are essentially the same. It's the total amount of sugar, regardless of the whether or not it's table sugar or HFCS that is the issue. The AHA, CDC and WHO make no distinction between HFCS and sucrose and instead recommend keeping both below 5-10% of calories.

Here is a 2022 meta analysis that states that compared with sucrose, HFCS did not significantly differ on weight, BMI, waist circumference, blood pressure, total cholesterol, LDL, HDL, or triglycerides in the included trials. My point here isn't a defense of HFCS and I'm not saying it isn't bad for you. I'm saying that above a certain level ALL sugar is bad for you and table sugar and HFCS should both be limited in the diet because they both cause equally bad harm. The problem with demonizing HFCS alone is people actually think sucrose in the same amounts as HFCS is somehow healthier...it's not!

I'll make the same argument against taking collagen or any other specific source of protein for any specific reason - all the protein in collagen is digested into individual amino acids and physiologically these AA are no different than if you ate a steak or chicken or greek yogurt. Ok...the ratios of AA differ but in a normal diet with complete protein sources with all the essential AAs it's a non-issue. It's just marketing hype.

https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1013310/full

 

[SC Maintenance]

Mine is leaking at the balancer , does that matter?

Front main seal - likely dried up and no pour in is likely to fix it completely. How much of a leak?

What engine? Generally much easier repair than rear main?

I would try conventional 10W-30 or 10W-40 and see if either helps at all.

 

[hunter2929]

It's a 2.8 pontiac , it's very slow, enough to wet the area but not really drip on the ground.

 

[hunter2929]

Don't want an argument but HFCS is banned around the world. I used it as an example, just like they still sold lead paint at one time knowing the danger..

Can we stay on subject now.