Product Claims to Reduce Engine Pings
Question: I have a 1982 Volvo in excellent condition with only 25,000 miles on it. But even with 91-octane gasoline, it pings. Is there anything I should do for it or does this mean a poor future for the car? --A.B.
Answer: Since you have accumulated so few miles over such a long period of time, it sounds as though you make only infrequent trips and very short ones. This is exactly the type of usage that creates engine deposits, which can cause engine ping or knock. It is the uncontrolled detonation of the fuel that makes the noise.
Engine deposits can contribute to ping in two ways. If you burn leaded fuel, the sheer volume of carbon deposits that build up inside your combustion chamber can raise the compression ratio of the engine. When that happens, the engine effectively needs a higher octane gasoline, and if it doesn’t get it, then it will start to ping.
Since the introduction of unleaded fuel, however, engines are not developing nearly as many deposits, because the fuel burns cleaner. But motorists are still finding that their engines develop ping. The reason for this is that even small engine deposits can insulate areas of the combustion chamber and thereby create hot spots. These spots can create uncontrolled burning of the fuel.
One way of addressing this problem is to constantly buy higher-octane gasoline, but this is not practical. At some point, the engine will need a higher-octane rating on the gasoline than is available. It is also needlessly expensive.
The only other alternative is to get rid of the deposits. They can be cleaned out of the combustion chamber manually, but this is very costly, because it requires partial disassembly of the engine.
There are a number of commercial brands of engine-deposit cleaner available on the market. Many motorists are skeptical of these products, and rightly so. But a new product has recently come on the market that has at least some scientific backup to its claims.
It is Pro-Care Cleanup, produced by Chevron. The product contains the firm’s proprietary chemical Techron, which is added to the company’s gasoline at much lower concentrations. Chevron product specialist Fred Peterson makes the claim that a single treatment of Pro-Care Cleanup can reduce combustion chamber deposits enough to decrease the engine’s octane requirement by two to three points.
That means if you need a mid-grade fuel of about 89 octane, you could get by with a regular fuel with a rating of 87 octane.
Those claims are backed up in several scientific papers submitted and published by the Society of Automotive Engineers. Chevron does not know why Techron works but asserts that there is significant evidence that it removes carbon deposits on a molecule-by-molecule basis.
The company conducted several tests of fleets of 30 cars, measuring the ability of the product to reduce combustion-chamber deposits and fuel-injector deposits. It found reductions of deposits in 83% of the cars tested. It was even effective in eliminating deposits from intake valves, which are particularly difficult to remove.
The additive is not cheap, though. A single treatment costs $5.99. A related product called Stay Clean, which contains a lower concentration of Techron, costs $5.49. And Fuel Injector Cleaner costs $4.99.
I am running my own informal test, in which a number of people with ping problems in their cars are using the Chevron product.
Audi, which has had a problem with engine deposits in its Audi 5000 cars, has recommended Techron as an effective way to keep combustion chambers clean.
As for the reader’s Volvo, a moderate amount of ping is not necessarily harmful to a car and does not mean that the car is destined for an early demise.
Of course, if the car is not properly tuned, problems other than engine deposits may be causing it to ping.
