2003 Ford Mondeo - Engine Troubles

Not sure it matters what kind of car it is, but this is a pretty classic "lost one or two cylinders" problem. You may have a bad spark plug, you may have bad/disconnected spark plug wires, you may have an oil leak into the cylinder causing fouling of the plug, or if this is not electronic ignition, you could have a distributor problem.

One way to tell is to go cylinder by cylinder and while the motor is OFF, disconnect one spark plug wire. Then, restart the engine.....if there is no change in performance, you have found the "weak" cylinder. If the disconnected wire DOES CHANGE THE PERFORMANCE, you've found a good cylinder. Obviously, if the disconnected wire DOES make a difference, reconnect it before going to the next cylinder. Remember to turn off the engine in between pulling spark plug wires or you will get a pretty bad shock from the 10-20,000 volts on the wire.

I am wondering whether a bad spark-plug wire or short in the coil supply couldnt also cause such a problem. It has been a long time since I repaired automobiles and ignition systems have changed a bit.

...pretty classic "lost one or two cylinders" problem?? I thought lost one or two cylinders is/are always ugy. And what's up with this classic (lost) stuff? Next people will be talking about iconic lost cylinders!

Anyhow, the problem is, most likely, not misfire...more likely electronic ignition. Problem is, the symptoms could have been better described. (Increasing fuel to an engine misfiring or missing on one or two cylinders will generally exacerbate, not alleviate, the symptoms. This car went in production (long after ignition points went away) when the TFI-IV ignition modules where in use by Fords...and the problems with those are well known.

UG

Thank you very much for the encouraging replies and advise. I have recently had the car serviced and the spark plugs, petrol and oil filters changed. Even the gear box transmission oil was changed. After the service the engine missing beat problem increased and one mechanic after checking all the distributor and plug wires quoted the wires with Kerosine oil. This has helped and the missing has reduced a lot. However a mechanic at the Ford gerage suggested that the car being totally electronic could be having a problem with the coil or CPC???? I am not very sure what this is but I believe it is computer related or some electronic component in the car that may need to be replaced.

Problem is the parts are very very expensive for a trial and error game and not worth spending on an 2003 model. I really do not know how to diagnose the problem without the trial and error method of spending unnecessarily on every expensive parts. It is a very good and strong car and I like it, but I need a simple and cheaper method to fix the problem.

Thanks to all for their help and guidence.

Best regards and have a good day.

With this one you're better off not to circumvent the Ford service department, but even at that you'll need to keep close eye and compel them to do the diagnostics completely...and that they know how to interpret the "scope-out" report...and how to perform the needed replacements or alignment. This is much more efficient than getting guesses and work based on guesses from mechanics; most reputable shops (and any mfr authorized service department) would have insisted on diagnostic test before any work or work authorization (except the diagnostic). Diagnostic tests are not that expensive...most likely between 80 and 150 dollars US. If it turns out to be more serious (that is, more expensive) than, say, an ignition module (at less than $500) you might want to consider entering a dispute and/or warranty claim process...to hopefully persuade/compel the manufacturer to extend pro-rata warranty coverage...that is, of course, provided the car has less than 100,000 miles (metric equivalent). Another thing, when discussing and authorizing work based on a diagnostic printout:

• Insist on a copy of the printout and ask for full explanation
• Inquire as to the assigned technicians experience level and qualifications...expecially electrical and computer system qualifications.
• Obtain guarantee preferably in writing or initialed service order to indicate that the recommended replacement/service WILL fix the problem...or they pay/re-repair...or that some certain number of repeated repair attempts will be sufficient to obtain service under manufacturer (implicit) warranty.