I recently bought a 98 Disco as a second car/project in pretty good shape because I've always wanted one and I am finding myself with a lot more free time for hobbies during pandemic life. Unfortunately and predictably I have noticed a small coolant leak from the base of the radiator, dripping from both sides. No white smoke in exhaust, no coolant in the oil, but I have an OBDII reading for P1193 (downstream o2) and P0125 Insufficient Coolant Temp for closed loop fuel control. I've seen some competing advice on how to best attack this. Disco had a full radiator rebuild in 2016 from the maintenance records. Leak has only drained about 1/4"" from the overflow reservoir in 2 days of light driving. No overheating, if anything it's been running cooler than the midpoint, and the car's heat has been working fine with no antifreeze smell. I'm suspecting a bad gasket at the base of the radiator or a small crack but I was wondering what you guys think?

 

I'd forget the P1193 for now. The P0125 is probably a coolant temp sensor. part: ECT8496R not expensive and easy to replace.

As for the leaking coolant, that could be leaky hoses or a cracked radiator. No way to tell other than cleaning and close inspection. Looks for traces of liquid and white-ish residue.

I sound like a broken record, but if you don't have an OBD live data set up, get to it. It will save you hours of time and hundreds in shop fees. The ability to see exactly what the engine ECU is seeing is super helpful to track down bad sensors, and other ailments.

 

Appreciate the advice, my inclination was to avoid the o2 sensor issue until the next time I need to pass emissions.

I'll swap out the coolant temp sensor and hope it clears that up.

Would you have a recommendation for a good OBD live data setup? Seems like there is a pretty big disparity in price between some of the leading products.

 

just happened to go through it on another thread....

https://landroverforums.com/forum/di...74/#post763232

 

Thanks! I actually found this post the other day while browsing around. Appreciate it.

 

Yeah, all the stuff Walt said.
I would add this though. I just jammed an Ultragauge in the obd plug. It was simple and thou can watch in live time the ecm inputs. Relatively inexpensive.

Coolant leak I would hunt with a pressure tester. I have one so I don't know if the parts houses still rent them out.