Has only been 2 years since the radiator was last cleaned of road debris. Removing today to access the water pump which is going to be replaced due to a squeaky bearing. This car a great highway vacuum cleaner. Don’t know exactly but all the trash is from about 8,000 miles of driving.
I have opined before that the rad needs to come OUT about every other year, basically when the coolant is changed. There’s no good way to clean those fins without it coming out.
When you go back together, make sure to seal up the gap between the oil cooler and the A/C condenser. I believe that greatly reduces the crud buildup in those lower fins.
I bought an 89’ Rouge XJ-S a couple months ago.
After pulling the radiator out a few days ago to rod it out, I was horrified that such a low mileage car can look like Autumn even though its only spring.
See photos. Over 6 handfuls… I will be making another post about it in near future. 
When I first bought, I had changed the thermostats and coolant (even before rodding the 60% clogged radiator), and it still managed to stay around normal operating temperature.
Although during prolong running, the temperature crept past the N. (I knew radiator was due to be pulled)
I believe at a minimum these radiators should be pulled every 5 years if driven regularly and cleaned properly.
As Kirby mentioned, make sure to put rubber/foam within the gap between the AC condenser & oil cooler it will certainly stop full scale debris from getting it.
This is about as bad as I have ever seen honestly.
Also, at least for the face lift models I think having the spoiler tray installed makes a difference on how much trash is pulled up. Mine was missing when I got my car ten years ago, I made my own with the “muffin pan” mod and an aluminum sheet and that helped a lot. Now I have a new plastic tray and that area seems to be staying clean. I just put in a return hose temp sending unit and will drive it with and w/o the tray to see how much affect that has on cruising temp.
Wow! Thought mine was a mess. Glad you are cleaning it up. Suggest that while you have gone this far that the fan shroud be taken out and cleaned up and painted. See there is some rust on it and it would not take that much work to clean it up. Check the rubber flat while you’re there. Not to make you worry but see that the car has its’ original fan which some say can disintegrate and ruin your day. Changed mine to a black fan years ago.
Yeah, definitely replace that yellow fan.
I have a black fan to replace it with. It’s something I always do. I don’t trust the yellow ones either!
Don-I don’t have much in way of rust, the whole car is just about rust-free thankfully. It may look like it w the dirt.
Take a look at the debris I pulled out…!