Newbie to this Forum.. I have a problem which has plagued both me and my local dealer for the last two years. The car is an automatic 2006 C70 SE T5 with approximately 163K miles on the clock. The timing belt was changed at 110K. No other work has been done on the engine/transmission. Any help in diagnosis/resolution would be much appreciated.


Essentially when I am driving (at various speeds and loads) the engine effectively 'Hiccoughs' for no apparent reason (and on occasion will then die causing me to head for the side of the road !), on other occasions after hiccupping the engine will pick up as if nothing had happened. On some of these occurrences the car will display the <<Engine system service urgent>> on the display panel BUT fail to log an ODB2 code in the computer (helpful).


If the engine dies, then waiting 5 or so seconds seems to resolve whatever caused the problem and once again no meaningful diagnostics are left to follow up.


Any ideas anyone ??

 

Gotta have the codes read with a better scanner. There are codes stored, certainly.

 

Change all plugs and COPs. Get a good OBDII reader from Amazon.

 

Or you could waste a bunch of money and guess all the coils. That's not going to be the problem though.

 

I'd probably play a hunch and replace the fuel pump relay. relays have contact points that can get sticky and their behavior can change with temperature (whether from load or weather) - when you shut down the car, the relay can release and cool a bit and appear to be normal again. Any other symptoms - cold start/warm start stuff etc? Intermittents are a pain to diagnose particularly when they don't throw codes - you either need to trap the error or take educated guesses (starting with cheapest to fix and work your way up).

 

Change COPs only if not replaced in last 100k miles. I don't concern myself about the cost of me buying and installing the COPs on any of my cars. The benefit is worth the price when it comes to these electrical items that enable the vehicle to start/run correctly. That is why I replace all the plugs when 1 goes bad, they are all the same age and have the same use on them ! I don't go on the CHEAP, when I need to maintain any of my 5 vehicles, from the truck to the Meserati.

 

It all so might be a chaffed wire rubbing some where>check your wires.