Intermittent Fault - Maybe Spark Plugs?

shane3265 · December 11, 2012

Hi All,

Im sweating over this....

The car sometimes judders, almost feels like a misfire but no engine management light comes on. Seems to happen when the car is ‘under load’, ie low speed, uphill, and in 2^nd for example.

If the revs are kept high then the judder feeling doesn’t occur and the car is its usual smooth self. Its definitely not trying to stall; it feels different to that, although I must admit the conditions are very similar.

The problem started after I got a full service done by a random independent garage (never again!).

The car almost feels reluctant sometimes now, but maybe thats just me being paranoid, and maybe the cold weather has an effect.

Either way I know there’s something not quite right with the car and frankly Im really worried!

Because its very intermittent and difficult to replicate I cant think of what could be causing it - if it was a spark plug issue surely it would happen under normal driving conditions, same goes for coil packs (I guess). I would actually feel better about it if the engine management light came on, least then I could get the code form it and diagnose a misfire in theory.

Anyone ever experienced something like this?

Any thoughts or suggestions are more than welcome

Thanks guys

Shane

ChrisIS200SportTTE · December 11, 2012

Wierd! If it were me I'd look at throttle body, air filter and what fuel I was using.

Hope you get to the bottom of it :)

shane3265 · December 11, 2012

Thanks for the reply Chris, I tried changing the petrol station I usually fill up at and I also gave the car a tank of Shell V power to see if that had an impact but sadly no.

To my great shame I dont know enough about these things to diagnose the problem and fix it myself - even if I did I dont have the tools to check some of the basic parts!

Ive looked for a decent independent around Edinburgh but couldnt find any. Guess I will have to go to Lexus Edinburgh and get charged a fortune for someone to investigate. I suppose it will be worth it if they find the problem but I just dont know if they will - dont want to be out of pocket with no result!

Thanks again for the reply

sjrainsford · December 11, 2012

It's worth finding out what they did when they did the service first. Could be as simple as a plug not quite plugged in correctly. If they changed your spark plugs they may not have fitted the correct ones. A slight miss often points to the coil packs on these otherwise. But it's hard to tell without first getting the fault light come on, unless the system has logged a code. That may be worth checking.

CLONESCOWBOY · December 11, 2012

It could be a slight misfire, check it on OBD. mine turned out to be that but it was caused by the mechanic sparking the plugs of the head for timing check and he blew the driver in the ecu for injector 4, now im running lean, so now i have an ecu problem to sort out. but do check for misfire....

shane3265 · December 12, 2012

Thanks for all the replies guys, much appreciated. I just tried to PM a member here called Ormi who I hear works in Edinburgh but my message never got through for some reason. I was hoping he would be interested in pricing up some investigation work as he works for Toyota.

If there's anyone else around the Edinburgh area or further afield and you're interested in this then please contact me.

Ive got a big road trip coming up so want to get this sorted by next week. Looks like I will have to bite the bullet and go to Toyota in Newbridge, Edinburgh.

Thanks all