Are Oil Additives A Good Idea?

[MolaKule]

Originally Posted By: OnlySon
I bought a 98 Dodge Dakota Sport in August. I've noticed what sounds like a knocking sound. I've repaired the passenger side exhaust manifold studs/bolts/nuts and added a gasket; these Mopars are known for broken exhaust manifold fasteners. I know that's not the source of the sound. I haven't inspected the valvetrain yet. I'm leaning toward thinking the valves/rocker arms need adjusting or it might be a worn timing chain tensioner. The noise seems quieter in humid weather. I'm wondering if I can add an oil treatment when I next change the oil/filter that will quiet this sound? I don't want to damage the engine with or without introducing a product to the engine. I've seen mixed advice on several forums about the use/effectiveness of oil treatments. Is there a safe, effective product on the market made to help this? The engine has 70K miles on it and it consumes about a half quart every 1K miles. Thanks.


Adding OTC Oil Additives on a regular basis, when oils today have so much better detergent packs, doesn't make economic sense.

I think there are certain additives that can be used on a one time basis or few times basis to attack specific problems.

Otherwise, you're wasting your money.

 

[rockydee]

For a problem like mention here its kind of tough to diagnose not being able to listen to her. On project cars I've built or worked on over the years I'd toss some Rislone, Marvel Oil, or Kreen at 'em. It could be some junk plugging up a lifter and you'll clean her right up. It could be something downstairs and you'll be SOL. If you're lucky the additive will save you a bunch of time and money before you start pulling engine apart in the dead of the winter. Once you get her all sorted out use a good synthetic oil and change at reasonable intervals and you won't need to put any additives in her anymore.-RD

 

[OnlySon]

I changed the oil a week or two after I bought it. Walmart had the best price on Mobil Super 10w-30 and a Mopar oil filter. I will try a bottle of Rislone and let it try to work its way through the engine; it's due for another change in 1.5K. Maybe it will loosen any sludge.

 

[demarpaint]

Originally Posted By: OnlySon
I changed the oil a week or two after I bought it. Walmart had the best price on Mobil Super 10w-30 and a Mopar oil filter. I will try a bottle of Rislone and let it try to work its way through the engine; it's due for another change in 1.5K. Maybe it will loosen any sludge.


I'd give it a try, as others mentioned you might get lucky and save some money in the process.

 

[krismoriah72]

since the octane didnt help you are looking for mechanical issues now. Most likely timing chain slap. There will be little or no noise on acceleration, all noise on deceleration.

Sitting for 5 years - possible the owner was told it needed an expensive fix and they couldnt afford it.. so now you have the burden.

 

[OnlySon]

I've heard the term "deceleration knock" before.

The sound happens mostly while accelerating between 45 - 55 mph and then goes away. If I let off the pedal it goes away immediiately.

 

[Chucksta]

It's interesting that it happens most noticeably at a particular road speed. I would take it that you're saying that the transmission is in top gear, and that the acceleration is not in a lower gear ( kick down ). If the noise you're hearing is related to load at a particular R.P.M., wouldn't you hear it in every gear, as the engine, under load, passed through that same R.P.M. rev range?

As far as your original question, "are oil additives a good idea?", is concerned, IMHO, there is, unfortunately, no right or wrong answer. "additives", covers a lot of territory, different manufacturers, different formulas, different applications. As many additives are application specific, it's imperative that the problem you wish to rectify is even addressable by an additive. If the noise you're hearing is caused by something being "stuck", or Gunked up", then, absolutely, an additive that specifically addresses that specific issue may well be an easy and, hopefully, long term solution. No additive will repair mechanical issues. I'm constantly amazed by people who try to fix what is probably an injector issue, by pouring something into the oil, or address a gunk in the engine problem, by pouring something blindly into the gas tank. Simply put, drive-ability is possibly within the scope of fuel additives, stuck and gummed up stuff IF it's the cause of the mystery noise, MAY be within the scope of an oil additive.

As the vehicle had some extensive periods of not being run, every time it had been started was absolutely brutal to it, in terms of wear. Every start was a "dry start", in terms of engine lubrication. If I had a "barn find" that had sat for years, I would have taken out the plugs, poured oil into every cylinder and let it sit for a week. Before I started it, I would have drained the fuel system, changed the oil, and turned it over until I could see oil in the rockers, .. THEN started it.

If the noise is "something stuck", or something that needs to be cleaned, I would doubt that an oil change would do much to rectify the problem. Good quality oil, should, when changed out on a regular basis, keep a motor clean. I doubt, however, that it would clean years of sludge at a noticeable pace.

That being said, personally, I'd throw in some cheap dino oil and a can of SeaFoam into the oil as per the instructions. Worst case scenario, you're out $40.00. It will dissolve anything that is gumming anything up. The only other additive that may quiet the noise would be something like Slick50, or something similar. That type of additive, theoretically, (PTFE), may coat something enough to stop it knocking audibly.

But seriously.. I'd be curious about why it was most noticeable at a certain road speed. An engine noise, presenting itself at a certain load and R.P.M. should be present at that point regardless of road speed. Just tossing this out there, but if you can, note the RPM at the speed you noticed it most prevalent at, now, duplicate those same conditions with a foot on the brake in first gear, to hold it in that same "zone". Same noise? If not... maybe it's not the engine.

 

[OnlySon]

Thanks to all who submitted advice.

In the past twenty-five years I've had several cars:

83 Regal V6 (used)
89 Accord 4 cylinder (new)
98 Maxima V6 (used)
02 Durango V8 (new)
03 CR-V 4 cylinder (used)
98 Dakota V6 (used)

I find it odd that the only vehicles that have had any engine noise have been the American-made v6s. The Nissan makes no unusual noises at all and it's got 180K on it; it still runs well. The USA made ones had/have less than half that. This may be my last V6 by an American automaker.

 

[Clevy]

Originally Posted By: OnlySon
Thanks to all who submitted advice.

In the past twenty-five years I've had several cars:

83 Regal V6 (used)
89 Accord 4 cylinder (new)
98 Maxima V6 (used)
02 Durango V8 (new)
03 CR-V 4 cylinder (used)
98 Dakota V6 (used)

I find it odd that the only vehicles that have had any engine noise have been the American-made v6s. The Nissan makes no unusual noises at all and it's got 180K on it; it still runs well. The USA made ones had/have less than half that. This may be my last V6 by an American automaker.


I suggest using a can of motor oil saver made by liqui-moly. It's an ester and it has boron. Should help clean the lifter without a solvent and help it pump up n
After 1000 miles add a can of mos2 made by liqui-moly. Should help the clatter

 

[vo_marz]

Originally Posted By: OnlySon
Thanks to all who submitted advice.

In the past twenty-five years I've had several cars:

83 Regal V6 (used)
89 Accord 4 cylinder (new)
98 Maxima V6 (used)
02 Durango V8 (new)
03 CR-V 4 cylinder (used)
98 Dakota V6 (used)

I find it odd that the only vehicles that have had any engine noise have been the American-made v6s. The Nissan makes no unusual noises at all and it's got 180K on it; it still runs well. The USA made ones had/have less than half that. This may be my last V6 by an American automaker.


V- type engines are inherently unbalanced FYI...

If you want a low upkeep reliable commuter of an engine...

the Inline / Boxer configuration is the way to go, preferably in even numbers for balance reasons(they usually fire in pairs to cancel out each other)

feeding a broken horse top grade hay wont make it less broken imho .

 

[OnlySon]

Thanks to all for the advice. I changed the oil in the truck about a week ago. This time I substituted one quart of oil for a quart of MMO. I am happy to say the sound appears to be gone. I guess it may have been a hydraulic lifter issue being plugged. Whatever it was appears to be gone. The engine sounds like it should now. Much quieter now upon accelerating and hill/grade climbing.

 

[jk_636]

Originally Posted By: OnlySon
Thanks to all for the advice. I changed the oil in the truck about a week ago. This time I substituted one quart of oil for a quart of MMO. I am happy to say the sound appears to be gone. I guess it may have been a hydraulic lifter issue being plugged. Whatever it was appears to be gone. The engine sounds like it should now. Much quieter now upon accelerating and hill/grade climbing.


Good decision. MMO is one of the few oil additives that consistently yields outstanding results. Enjoy your smooth new ride!

 

[OnlySon]

Thanks.

 

[Boss302fan]

Originally Posted By: Clevy
Originally Posted By: OnlySon
Thanks to all who submitted advice.

In the past twenty-five years I've had several cars:

83 Regal V6 (used)
89 Accord 4 cylinder (new)
98 Maxima V6 (used)
02 Durango V8 (new)
03 CR-V 4 cylinder (used)
98 Dakota V6 (used)

I find it odd that the only vehicles that have had any engine noise have been the American-made v6s. The Nissan makes no unusual noises at all and it's got 180K on it; it still runs well. The USA made ones had/have less than half that. This may be my last V6 by an American automaker.


I suggest using a can of motor oil saver made by liqui-moly. It's an ester and it has boron. Should help clean the lifter without a solvent and help it pump up n
After 1000 miles add a can of mos2 made by liqui-moly. Should help the clatter


I agree 100%... MOS is really a good additive and just might help the issue you are having. You need to drive the vehicle for 15-20 minutes each time you drive it to really heat it up. It may take up to 250-500 miles but MOS can quiet down/smooth out your engine.