Join Date: Dec 2012
Location: Tatamagouche Nova Scotia
Feedback Score: 0 reviews
Wrench light is, as I seem to recall, on 2005 and later vehicles only. they also had boost gauges, so if it's over-boost you should be able to see it on the dash gauge. Normal max boost is around 28 lbs, but if the turbo vanes stick you can see up to around 35 psi. That is enough to start to cause head gasket problems, hence the light. The more common reason is the oil cooler is clogged and your EGR cooler is about to fail due to overheating. The light comes on when the delta between coolant temp and oil temp exceeds 15 degrees under a certain set of load, usage, outside temp and probably a few other conditions. The normal test is to read the temps with a OBDII data reader (Scangauge II and others) while driving unloaded at 60 - 65 mph on a flat highway. If your temps creep up to show a difference of close to or more than 15 degrees, your oil cooler needs to be changed. As far as I know, there are indeed no codes for either condition, just the light.