Why Does My Car Splutter or Chug?
As someone who deals with cars day in and day out this is a question I get asked very often. If you Google the question you will find the widest (and wildest) selection of answers you ever wanted to see. So, I thought I might write a bit about it to give you my take on the answer.
All vehicles are different. They have all been through different experiences in their lives. Because of this there is no one correct answer to fit all cases. However, as a specialist contaminated fuel technician my first thought when someone tells me that their engine is chugging is “have they misfuelled it”. Attempting to drive a vehicle with contaminated fuel can cause the engine to splutter and chug. This is the easiest thing to check and it won’t cost you a thing: Simply take a look at your last few fuel receipts, or open the filler cap and take a sniff. Both petrol and diesel have distinctly different smells. If you don’t know the difference then get another vehicle that you know is fine and smell the fuel in it to compare.
Once you’ve checked this, find a diagnostic tool (or find a friend who has one) and find out what fault codes are reading. Other problems that can cause an engine to sputter include, but are not limited to:
– Faulty spark-plugs/coils
– Defective throttle body
– Mis-adjusted timing
– Blocked, clogged or worn fuel lines, filter or injectors
– etc
Get the diagnostic checks done before you send it into the shop or else risk building up a huge bill for “exploritory surgery” as the mechanic tries to fix all possible faults without finding the actual cause and just fixing that.

