Jeep Grand Cherokee P0308

Had a engine code come on in Jeep and engine began running a little rough – especially under load.  Now the Jeeps all have a way to check engine codes built into them!  All cars should… also can check all gauges and lamps as well.

So first a tip:  To test lamps and gauges – press and hold trip reset button with ignition turned.  While holding trip reset in, turn ignition on (just to first click).  All gauges will go to top, all lights will illuminate and digits such as odometer will count through all numbers possible.  To check codes.. turn ignition off.. then turn to first position only.. turn back off.. turn back on to first position.. turn back off.. turn back on to first position only.  Any codes will display – ending in the word done.

So I found I had a P0308 – which is a cylinder misfire on cylinder number 8.

Well there are several things which would cause an cylinder misfire and misfire – it did seem to run fairly smoothly but a bit rough when normal – but go really rough under higher speeds or load.  So.. first test is the easiest and is coil replacement.  Now cylinder 8 is the most difficult one to get to — but not too bad on the Jeep.  So I picked one up – I often simply swap them and see if it moves – but if you can get one replacement is an easy route as well as they are not terribly expensive.

Pulled it out – put in new and tested it out.  Good as new – or so it seems – a few miles will tell for sure.

Now some ask why the Jeep – well there are a few Chimney Sweeps around the country who use a Jeep for service.  Some use vans – I did have one – but the Jeep is far more functional for most things.  Tow a trailer when I need more with me… but take the trailer along or drop it.. the Jeep can get into roadways in Muskoka that no van would go.  There really is no other realistic option for a Chimney Sweep who is working in some of the area I cover.  Unplowed or semi-plowed roadways – 2 wheel drive vans just don’t cut it.. the Jeep goes through without blinking an eye!   When it comes to getting in and back out – the Jeep is hard to beat.

Author: Chimney Sweep

WETT Certified Advanced Chimney Sweep - Loving It Every Day