My 2002 CR-V recently developed a small coolant leak and I assumed it was the radiator since I think it's never been replaced so I bought a new OEM replacement from Honda. I dug into it last Saturday and discovered the thermostat gasket leaking and I know the previous owner had that replaced with an aftermarket unit (I have a lot of the maintenance records from the original owner and I am the second owner). I ordered the OEM Thermostat and well as the mating plastic block (unsure of the correct name) and plan to install them this weekend. My first question to all of you is this: should I install the OEM radiator anyway since I have to remove the existing one to replace the thermostat? Normally this is probably a no-brainer but I'm asking because the car spent the first 20 years of it's life in Texas and never saw salt and now it's up north in Michigan with me. If the original radiators are tough then maybe this one has a lot of life left in it since it never saw any salt until a couple years ago. I will probably install the new one anyway but I wanted to get some opinions from the experts here. My second question is this: the only radiator offered from Honda has the pipe extensions for the trans cooler…ie the same P/N radiator is listed for both automatic and manual transmission cars. Do I care? I assume just leave these capped, install it and move on with life, yes? Thanks in advance.

 

Many car manufacturers, including Honda, began installing radiators which have plastic sides. Over time the sides will crack and the radiator will leak. I've replaced mine with all aluminum TIG welded radiators whenever this happens, since all plastic replacements will eventually crack and leak and then have to be replaced. the replacements cost more but will last.

You should get a radiator pressure tester, available on Amazon for about $100. Pressure test the system; this will help you identify any leaks or other issues, such as a blown head gasket.

I don't know why you would have to remove the radiator to replace the thermostat - I have two Hondas and didn't have to remove the radiator on either to replace the thermostat.

Finally, good luck. You seem not to have much knowledge of or experience with car repair. You may be better off going to a trusted mechanic if you can find one. I heard there was one once, but I think he retired in 2019. Probably a made-up story anyway.

Oh, and by the way - expert car mechanics don't post on online forums. You're only gonna get opinions from DIY guys like me.

 

I've been working on my own vehicles for over 30 years but my question was directed at southern radiators. Up here in the north radiators often fail due to corrosion from road salt so I wasn't sure of the expected lifespan in a salt-free but extremely hot climate like Texas. If someone had responded "radiators last forever down here" then I would have left it alone.

Regarding the thermostat, I'm planning on replacing the thermostat housing at the same time because it's plastic and might be warped. Also, I'm a big guy with bigger hands and often I have to remove extra parts for adequate access.

 

Unless your thermostat is different than either of mine you have to replace the housing as the thermostat is built into it. In the hotter southern climate, plastic sided radiators usually last about five years or less.

Good luck with your repair.

 

Radiators usually fail from stiffening of the seals between the aluminum fin assembly and the plastic endcaps. Eventually, the stiffening prevents adequate sealing during the differential expansion and contraction of the materials. This is a function of age and heat, not salt exposure.

I would replace the radiator at that age if you have the system emptied and it is of that age.

 

Grade 50: that makes sense, I am replacing the radiator since I had to pull it up to access the thermostat housing.

pscarbror: to be specific, we're talking about the thermostat...which has it's own plastic housing...and also the actual thermostat housing that the thermostat bolts to (the plastic part with the brass inserts). Two of the brass inserts are spinning on the plastic so I have to replace this part as well. Not sure if this is a common problem with the Honda 2.4 engines?

 

Those inserts will hang or gall to the bolt, and when you loosen the bolt the insert comes loose and spins. I had this happen to me; I was able to replace the insert with a nut and bolt, but you may not be able to do that. Good luck removing that housing - I considered it but since you'll have to take half the engine apart to get it off, it won't be an easy fix.

Honda vehicles are generally reliable, but maintainability was not a design consideration.

 

I already have the radiator out so access to the thermostat housing was difficult but not impossible. I had the same experience as you: two of the three shoulder bolts were seized to the inserts. Question: is there any special consideration for torqueing the three shoulder bolts that go into the brass inserts? I can use a torque wrench but sometimes that's not sufficient on small fasteners that see so many heat cycles. I can add anti-seize but maybe it's best not to so they don't work loose. I'm a little hesitant to torque by feel because if over tightened they will spin in the plastic.

 

I use a 1/4 inch drive inch-lb torque wrench a lot on my Hondas. If you have a service manual it will give the correct torque. If you don't have a manual you can get one on E-Manuals or some similar source.

 

I do have a factory manual and don't have an In-Lb torque wrench but I can borrow one from work. I have good 3/8 and 1/2 inch torque wrenches but not an In-Lb one yet (it's on my list to buy).

Have you found that that the listed torque on these three shoulder bolts is sufficient? Normally I'd err on the tight side but I don't want to spin the inserts in the plastic. Did you lube the threads on yours or install them dry?

 

Honda nuts and bolts are fragile, and you must torque them to the exact specifications. Too loose and things leak; too tight and you'll break or strip something. I bought my inch-lb torque wrench to torque gun sight rings. I used it once for that, and now nearly every time I work on one of my Hondas.

 

I typically put anti-seize on on everything because everything rusts up here but that lowers the friction of the threads so you have to compensate on how the wrench is set.

In the past did you install these three bolts dry? If you live in a salt-free are did you oil the threads and then torque to spec or install them dry?

 

I installed mine dry. In general I think that anti-seize is a good idea but as you mentioned, the torque specs are based on dry components. You can always guess what the wet torque should be but you run the risk of it being too tight or too loose. I did mine dry and added a silent prayer that I'd never have to loosen those bolts again.

 

I will probably do the same thing...including the silent prayer. : )