Sometimes when you look under a machine, normally slightly older in age, you see smoke coming out a pipe. Have you ever wondered what that is?
You have red engine oil low pressure light which comes on when you have low oil pressure and you have a high coolant temperature and sometimes a gauge as well to tell you when your engine is running hot. If you have smoke coming out your breather just think of it as a warning to say that when the winter comes this engine is going to be a bugger to start.
Power is generated in an engine when the piston is nearly at the top of its stroke, the diesel is injected and basically a small explosion happens and all of that ‘explosion’ is supposed to be above the pistons driving them downwards. If you’ve got smoke coming out the breather and the engine is breathing harder than a pervert in a playground it means that either the cylinder bore or the piston rings are worn. Some of that explosion which is effectively exhaust smoke, by-passes the rings and ends up in the cylinder block, the only way out then is via the engine breather.
All engines must breathe because you always have a bit of crankcase compression to allow for displaced air beneath the pistons when they are going up and down the cylinder bore.
More modern engines don’t have the external breathers to meet emission regulations. For example, Yanmar TNV engines are internally breathed where the crankcase is connected to the air inlet, either through a pipe or through a valve in the rocker cover. This means with the Yanmar engine you never get the tell-tale smoke coming out the breather but if you were to take the engine filler cap off you see the smoke in there. Another sign is if the engine only has a small plastic dipstick you see it bobbing up and down in the block or dipstick tube as the pressure caused by the crankcase compression keeps lifting out of its seat.
So, if your Yanmar TNV engine is hard to start don’t start throwing money at it before you investigate properly. As the largest stockist of Yanmar TNV engines in the UK it a regular thing to have an enquiry from a customer whose engine is hard to start in the winter. They’ve normally put new glow plugs in it, had the injectors over-hauled and tried a host of over things all to no avail. When I tell them to get it running and then take the dipstick out they are amazed that there is more smoke coming out the Yanmar dipstick hole than there is out the silencer!!!! I then get them to check the air inlet side and normally there is a hole in it so its sucking dirty air in or, worse than that, the air filter is that clogged up it sucked itself inside out and generated a hole for dirty air to get sucked in. Its then new engine time as with all Japanese engines they are uneconomical to repair and have gone the way of the telly. For those of us of a certain age, years ago when your telly went wrong to took it to a man down the road who fixed it. These days that man is dead, the telly repair shop is closed and is now selling vapes so you chuck your telly in the bin and head off to Curry’s if you’re over 50 to buy a new one or, if under 50 go on-line and order one.
Before you start throwing good money after bad on your Yanmar engine when it won’t start, ring PES for some good old-fashioned advice and as the largest stockists of Yanmar TNV engines in the country we’ll supply a brand spanking new one for a lot less money and hassle than you think.
