Detergent Oil

[Doug&Deb]

I believe detergent oils were introduced in the 50’s due to the rise of ohv engines. I’m sure they were marketed as a wonder product for engines. I’m curious about how many prematurely failed because of sludge migrating to places it shouldn’t have. 

[martybose]

When I bought my first car (a 1958 Volvo 444) I had no idea that it had been run on non-detergent oil, so I promptly changed the oil and filter with detergent oil.  I was back three days later wondering why my oil pressure had dropped; they showed me the plugged oil filter.  So for the next couple of months as soon as I saw the oil pressure starting to drop I would replace the oil filter and top off the oil.  I must have changed it 6-8 times before it stopped plugging up.  But I think that the sludge must have been holding the rings in place, because it soon started burning oil.  I eventually had to put a fresh engine in.

[joecoozie]

On 9/28/2021 at 7:50 PM, martybose said:

When I bought my first car (a 1958 Volvo 444) I had no idea that it had been run on non-detergent oil, so I promptly changed the oil and filter with detergent oil.  I was back three days later wondering why my oil pressure had dropped; they showed me the plugged oil filter.  So for the next couple of months as soon as I saw the oil pressure starting to drop I would replace the oil filter and top off the oil.  I must have changed it 6-8 times before it stopped plugging up.  But I think that the sludge must have been holding the rings in place, because it soon started burning oil.  I eventually had to put a fresh engine in.

I have always gone by the rule that if a car has been run with non-detergent oil from new for many years, and the engine has never been rebuilt, that non-detergent oil should be used. I always, at the very least, drop the oil pan, clean out the oil filter housing and remove the valve covers in order to remove all the sludge that has accumulated over the years. But ALL of the sludge/particles can never be removed unless the engine is dismantled and cleaned

When detergent oil is used in an engine that has only run on non-detergent oil, as martybose said, this could create issues with the sludge being circulated through the engine and/or the sludge being removed thereby creating issues such as smoking or ?????

[Doug&Deb]

I was wondering how many engines failed back in the day because owners bought the new type of oil. It was marketed as a wonder product for cleaning up the sludge in your engine.

[Bryan]

On 9/30/2021 at 5:47 AM, Doug&Deb said:

I was wondering how many engines failed back in the day because owners bought the new type of oil. It was marketed as a wonder product for cleaning up the sludge in your engine.

I wonder how many engines were ruined by knuckleheads like me flushing the oil with kerosene...

[Doug&Deb]

That’s not necessarily a bad thing. That cleans out the sludge. I used that method on my D24 before switching to detergent oil.

[blucarsdn]

I try to live by a rule that my father taught me over fifty years ago. "Don't Let The Directions On The Can Outsmart You"..

Detergent oil is one of the best inventions the engineers ever came up with for the internal combustion engines, along with thermostats and glycol bases   coolants. However, if the engine is not designed for detergent oil, ie; old engines with soft metal and babbit bearings.

Many years ago I had an employee that drove one of our company cars, a '79 GMC El Camino V8. Jim drove the car very day like it was his own, taking it home.

When the vehicle was due for service he would have the warehouse man sign him out five quarts of 20/50 GTX Castorl and a filter. Jim would take the oil, filter home with him and have a local service station service the vehicle. He would turn in the service ticket to the office for proof that the vehicle had been serviced.

When the vehicle had about 70k on it the engine seized up, the vehicle was towed to our normal repair shop. I received a call from the shop owner, he wanted me to stop by the shop. When I got to the shop I was taken into the shop area, where I was shown the engine out of the vehicle, the engine was a filthy black mess inside of the block, everything was plugged up with sludge. We called the oil dealer that we bought our oil from..

To make a long story short, the oil in the engine was not GTX 20/50 it was a cheap non-detergent oil. The employee confessed that he thought that the 20/50 GTX oil was to good for a company car so he bought non-detergent oil from a parts store to use in the GMC, using the GTX in his personal car.

We had a new engine put in the GMC and I fired the employee.

The moral of the story is, use the oil that the manufacture recommends for the engine, if the engine is a vintage engine that has been rebuilt to modern standards, use modern fluids in it, oil, coolant, etc. wm.