Blow-by blow-back


SPONSORED CONTENT: Engine blow-by problems can be simply fixed using cost effective maintenance strategies

Engine blow-by, smoke and oil use are related issues that, if ignored, can turn into very expensive repairs. Fortunately, more than 80 per cent of engine blow-by cases can be corrected at low cost, and without any downtime.

Typically, blow-by is cylinder pressure leaking past the piston rings into the crankcase. Commonly, it starts as cylinder glazing or carbon forming in the top ring grooves, both of which allow cylinder leak down, and some oil burning. Oil burning produces further ring deposits, and more blow-by. And of course, more internal engine stress.

According to Brid Walker, of Cost Effective Maintenance, "There’s a big window of opportunity to fully correct blow-by problems, before serious engine wear occurs.

"Most drivers can easily tell when thing aren’t quite right, for example , the engine is getting a bit tired or starting to breath heavy, it’s using more oil than usual or there’s a fair bit of smoke out the exhaust."

Walker says using Cost Effective Maintenance’s "Truckies Blow-by Pack" is the logical solution, because it directly addresses the root cause of blow-by.

"It does this by enhancing combustion to burn off cylinder glaze and carbon (particularly from the top ring grooves).

"To do this, FTC Decarbonizer is added to the diesel at each fill, and you literally just drive the engine clean! The decarbonizing process is gentle and progressive, but efficient, even cleaning turbos and DPFs."

Walker adds that most engines will also need cleaning from the oil side to restore full cleanliness to the lower piston rings as well. This involves running flushing oil concentrate through the engine. It uses detergents to target hard, baked-on deposits and persistent sludge, and according to the manufacturers, restores "as new clean" throughout.

"The longer blow-by is ignored, the more carbon accumulates in the engine. Black smoke increases, and oil soot increase. Performance and fuel efficiency deteriorate. Excessive carbon on pistons can cause rapid wear. Most broken piston rings are the result of carbon accumulating in the ring grooves.

"By cleaning the engine up, and more importantly, keeping it clean, the risk of engine failure is greatly reduced," he says.

 

Real Life Examples

The photos below are examples from a Caterpillar D11R dozers operating in Queensland’s Bowen Basin a decade ago.

Caterpillar 3508 (8,000 hours): Bad blow-by, bad wear and major carbon build up

Recommended rebuild life was about 11,000 hours. There were many failures due to severe carbon build up, some with only 3,000-4,000 hours. Typical rebuild intervals were 8,000-10,000 hours.

One 10-piece fleet using FTC Decarbonizer stood out! The first engine was stripped down at 15,000 hours, and was found to be in excellent condition. After a while they settled on 18,000-hour rebuild intervals.

Caterpillar 3508 engine (15,000 hours): No blow-by, little wear and little carbon with FTC Decarbonizer

Increased exhaust soot fouls turbochargers, EGR valves and diesel particulate filters. Increased oil soot chews out turbo seals. Many catastrophic failures result from neglecting blowby.

But by correcting blow-by issues, engines operate with much reduced stress, more efficiently and much longer. The key to getting long life from Euro V emission controlled engines is burning the fuel clean for low exhaust soot, and maintaining low oil soot levels.

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