* Engine Misfire: A misfire is when one or more cylinders aren't firing properly. This can cause shaking (especially at idle) and potentially smoke (depending on the severity and cause of the misfire – burnt oil, fuel). Causes can include bad spark plugs, wires, ignition coil, or even a problem with the fuel injectors.
* Worn or damaged engine mounts: These mounts isolate the engine from the chassis. If they're worn, the engine can vibrate excessively, causing shaking. While this alone wouldn't cause smoke, it could be a contributing factor if other problems are present.
* Low engine oil: Insufficient oil pressure can lead to excessive engine wear, misfires, and the potential for burning oil (resulting in blue or bluish-grey smoke).
* Failing transmission: Problems with the transmission can also cause vibrations. However, transmission problems generally don't cause smoke unless there's a significant internal failure leading to oil leaks.
* Exhaust system leak: A large exhaust leak before the catalytic converter can cause rough running and shaking. It generally doesn't cause smoke, unless the leak is near a leaking oil seal or another source of combustion.
* Clogged catalytic converter: A severely clogged catalytic converter can restrict exhaust flow, leading to a rough running engine and possibly smoke. The color of the smoke is important here. White smoke usually means coolant is leaking into the engine, while black smoke typically means excess fuel is being burnt.
* Head gasket failure: A blown head gasket can allow coolant to mix with oil or enter the combustion chamber. This usually leads to white smoke and overheating.
The smoke color is crucial:
* Blue/Grey Smoke: Usually indicates burning oil. This points towards worn piston rings, valve seals, or a leaking head gasket.
* Black Smoke: Often means a rich fuel mixture (too much fuel being injected). Could be a problem with the fuel injectors, mass airflow sensor, or other fuel system components.
* White Smoke: Typically indicates burning coolant. This is a serious issue and often points to a head gasket problem or a crack in the engine block or head.
What to do:
This is not something to ignore. Continued driving with these symptoms could cause significant engine damage. You should:
1. Don't drive the van extensively. Minimize driving until it's properly diagnosed.
2. Have a qualified mechanic inspect the vehicle immediately. They can diagnose the problem accurately and recommend the necessary repairs. Ignoring this could lead to costly repairs or even engine failure.
Ignoring these symptoms can lead to significant and costly damage. Professional diagnosis is essential.
