Cylinder blowby (excessive crankcase pressure) is a common and worrying problem encountered by most truckies at some stage in their career. Concern is certainly justified, because it typically means an expensive engine rebuild is necessary, and most mechanics and dealers will recommend it.
But, according to Brisbane-based Cost Effective Maintenance, wear is not the most common cause of blowby. Piston ring deposits, sufficient to cause fouling in the ring groove, and/or cylinder glaze account for about 80 per cent of blowby issues.
As founder Brid Walker says: “When you’re faced with a possible rebuild, you need to ensure that your money is well spent.
“Our advice is always to get everything clean first. Then you know where you’re at,” he says.
“There’s a very simple, low-cost, DIY procedure almost anyone…
