Before I hit the road for Radwood NorCal a few weeks back, I successfully swapped a brand-new Nissens radiator into my 1997 Land Rover Discovery. Everything went off without any kind of substantial hitch, though there were still some mild hiccups. Here’s how it went.

Since I got the Landy, I’d been experienced some frightening coolant temperatures. Even while cruising around on dreary, overcast, 60 degree days. Nothing’s worse than being stuck in traffic on one of Los Angeles’ worst freeways and having to blast the heat with all the windows down, just to keep the needle from moving up toward the red. This most likely meant it’s high time I swap out my Discovery 1’s original radiator in favor of something brand-new and for sure un-clogged (apparently, the factory ones clog up really easily).

I have a record of the previous owner doing the water pump, thermostat, and a coolant flush, so I knew those weren’t the culprit. I was convinced it was the radiator.

Making the Right Choice

Though, was it the right choice? The one I received a few days after ordering it from was indeed a Nissens, but it was something like 30% plastic. Turns out this is the Nissens that we Rover owners get these days.

After doing my research, I determined the best bang for my buck would be a Nissens unit. I knew the name, and everyone on forums seemed to be recommending it. I also found it for a decent price: 309 of my hard-earned dollars. Well, I wasn’t too stoked on this price, but considering the alternatives were cheap aluminum units of questionable quality and fitment on eBay, or paying an arm and a leg for an OEM unit, I figured take everyone’s advice and just buy the Nissens.

Welp, if people say it’s a good unit, it must be fine.

Tearing Into It

Fresh O-rings on the oil and ATF cooler lines. Image: Peter Nelson

I prepped for the big job by also buying new O-rings for the oil and ATF coolers (they’re integrated into the radiator; neat huh?) and all-new coolant hoses. My God am I glad I bought new hoses; just like the original radiator, all of the coolant hoses were original, and mostly needed to be cut off.

Pulling the oil and ATF hard lines was easy, and draining the coolant was much easier and less of a mess than I thought it would be. Luckily I had a massive drain pan to catch it all. Besides having to blast the crud off some of the connectors with brake cleaner, I was moving right along at a slow, methodical pace.

The original radiator had developed some small leaks up in the corners; whether replacing it would to solve my cooling issue or not, I know I didn’t want it leaking. I’m certain it had never been serviced before, either… I don’t want to think about the amount of sludge that was in it.

It’s out! Image: Peter Nelson

A minor pain in the ass happened with I went to remove the old expansion tank. I should’ve bought a new one, in fact, commenters on my last post recommended I do so, but I figured it’d be fine. Sure enough, I broke a connector that linked it to the top of the radiator. Joy. At least I don’t have to rely on the Rover for daily transportation. I quickly bought a new one from eBay which arrived two days later. A little peek inside the old one did reveal a ton of coppery sludge, though, so I’m glad I was forced to change it out.

Then, while connecting the oil cooler lines to the new radiator, I broke the plastic connector that goes from the radiator to the throttle body. This happened in 90-degree-or-so, ultra-humid heat. Remember when I mentioned the heat wave? You could say I was displeased.

That’s a Mulligan

I could’ve contacted AutoHausAZ and sought a warranty claim, or said the damage was not my fault. But I knocked it off with my own bare hands and I’m an honest gent, so I determined JB Weld was the way to go. Plus, I needed to get this beast road-worthy for Radwood NorCal, 425 miles away.

I needed to go to O’Reilly’s to buy more coolant, some hose clamps, and other various things anyway.

After three-whole-layers of brazing the plastic connector with thick wonder-sludge, it ended up holding very tight. Plus, this was the coolant feed to the throttle body (I made sure the passage wasn’t blocked), so I’m assuming it doesn’t experience a whole lot of pressure. After connecting everything else, which was a breeze, and filling/burping the system, everything seemed to hold tight just fine.

JB Weld slathered. I also had to lightly trim the lower radiator hose. Image: Peter Nelson


I sealed the system, let it heat up, and cycle the fan, and still, no leaks! Well, one tiny exception: the connector I didn’t break was leaking ever so slightly. No big deal though, I tightened it a bit more and chalked it up to “keep an eye on it, keep extra coolant in the car.” After two 20-or-so mile journeys, the connector wasn’t leaking anymore, and no leaks sprung up elsewhere.

This included some revving out and generally just doing everything I could to get it really hot. But alas, my OBDII reader indicated that the system refused to go above 185 degrees Fahrenheit! This included idling at stoplights and cruising at different speeds/RPMs! For the love of God, what a freaking relief.

The truck in general just ran more smoothly, too. A truck that stays cool is apparently a much happier truck than one that’s gotta be nursed away from overheating. Who knew?

All buttoned up. Well, except for the top cover… I’ll throw that on when I can confirm after a few hundred miles that all’s well. Image: Peter Nelson

What’s Next

Post swap, there’s a little less noise going on under the hood. I’m not sure if it’s because I swapped in fresh Rotella 15W-40 right before I did the radiator, and maybe all the Seafoam I’d been running in the previous oil melted away a bunch of crap, but ticking has gone down significantly. Or, because the engine was staying consistently cool, it was indeed just really happy.

As I mentioned in a previous blog, I can lightly rest on my laurels now that I’ve got over 850 miles of solid reliability.

I did get a Check Engine light before I started the radiator job. A quick scan a few days later revealed it to be P0430: “Catalyst System Efficiency Below Threshold (Bank 2).” Could this be a leak at the exhaust manifold that resembles valvetrain tick? Though, again, the ticking noise went down post-radiator job…

I also noticed a small leak coming from the master cylinder reservoir while wrenching.

Sigh, never a dull day when trying to make a Land Rover as reliable and leak-free as possible.