'90 Honda Civic cooling problem, DIY radiator installation questions

OK, here’s the story.
About a month ago, I noticed that my 1990 Honda Civic DX (with automatic transmission and A/C and ~75,000 miles) started getting hot
within 5 minutes after starting out. Almost to the red line on the gauge. I was stuck in traffic when I noticed this. I immediately tried to pull off a freeway exit. As soon as I got off the exit, I noticed the temperature drop almost instantly on the gauge from the line below the red to midway on the gauge. But then a couple of minutes later through town, the temp went back up again, only to drop back down later when going back onto the freeway. It did this on the remainder of my freeway trip and ever since then. Doesn’t matter when or where I start out (morning/noon/night, freeway/town), this pattern is consistent. It continues this same pattern: a couple of minutes after starting it would go to almost the red line on the gauge, a couple of minutes later back down to midway on the temp gauge, back up to almost the red line, back down, etc. etc. etc. Never overheated to where steam was pillowing through the hood. As it happened during the Christmas holiday season, I passed it off for fixing until after the holidays, driving it all the while. I would put on the A/C just to keep the fan blowing on the radiator.
I did a little research and concluded (rightly or wrongly) that my thermostat was stuck. So I went to Honda last week to get a thermostat. However, as soon as I was about to replace it, I saw the cooling fins on my radiator were bad. They were disintegrating, crumbling. Whether the thermostat is the root of the problem or not, the radiator will most definitely need to be replaced (I intend to keep the car for at least a couple of years). So I decided that I will go ahead and have the radiator replaced.
My questions to you folk:
Do you think that the radiator is the root of the problem with the symptoms I am having? Initially, I was hesitant to think the radiator was the problem because if the radiator was that bad, wouldn’t it lead to the car always running hot (i.e., not cool and hot like it's running now)?
OK, more importantly, I am thinking that I will attempt to replace the radiator myself and have some questions regarding this. I normally would send the car to Honda, but right now I am trying to pinch pennies as I just bought a new home and have a new child in the family. BTW, I am not a mechanic, but I consider myself fairly handy as I do regular maintenance on the car (tune-ups, oil changes, etc.) and have done slightly more significant repairs to my previous car, a ’83 Honda Civic (water pump replacement, muffler replacement, starter replacement, etc.).
1)    Is the work involved too much for a “backyard mechanic”? 2)    Do I need any special tools the average “backyard mechanic” would not have access to? 3)    How much will a new radiator be (price range)? 4)    Should I purchase a Honda radiator? I know that many times buying genuine Honda parts, although more expensive, is always better in the long run. However, I understand that Honda radiators are plastic and am thinking maybe another type of replacement radiator (i.e., metal) would be better in the end. 5)    Can I do the job in a day? Will I need more than myself to do it? 6)    Any other advice you can give regarding the specifics about radiator replacement in Honda Civics of this vintage. As I understand it, I need to undo all the hoses (coolant, A/C and auto trans.) and fans (I think there’s two?) and brackets to get the old one out. Seems pretty straightforward. And then just reversing what I did. I also plan to put into a new upper and lower radiator hose and a new thermostat at the same time.
Thanks for your time, Chris
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From your description it sounds like the car is cooling down when you are going fast and heating up when stopped or in stop and go traffic. If that is the case, most likely your radiator fan does not run, either because the fan is bad or because the thermoswitch that turns on the fan is bad. Do you ever hear the fan turn on?
Seven wrote:

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No, the temp going up and down is not related to speed. It can heat up when I am going down a major hill out of the mountains. That's why I suspect it's the thermostat. Also, fan comes on and stays on when I put the A/C on. Even with the fan running, however, the temp gauge can still head north, just to come down a few minutes later. Again, I am thinking the thermostat is sticking and the coolant can't get back to the radiator to cool. Thus my quest to see if this could be the case from the gurus...
I do want to replace the radiator as well so there are no surprises later...
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On 11 Jan 2004 23:18:52 -0800, snipped-for-privacy@aloha.net (Seven) wrote:

When I had a few fins missing (areas about the size of the palm of my hand in each half) and disintegration in progress ('92 Integra), I ran the car for a month in 70-80 degree weather without any signs of overheating. I guess it depends on how many fins you have left but I'd tend to say: no, that should not cause the oscillations in temp you are seeing.

It's not that difficult - the difficulty is in figuring how to get things out in the right order without interference with other parts.

Check www.hondaautomotiveparts.com and www.radiators.com

I got a Honda/Acura one though others have reported success with aftermarket. Before you buy, check the make of radiator you have - Toyo or Denso (should be scripted on the top) and specify that - I know that Honda has two different parts because the fan shrouds have different mount points between the two. The Honda radiators come with a new cap.

Yes and no respectively, though having a 2nd person to assist, for actually dropping in the new one, can be handy to avoid gouging/damaging it. With the radiator out, you'll also have access to many areas you'll want to clean up for dirt & corrosion.

You shouldn't have to disconnect any A/C lines - once the top brackets are off, they should push out of the way and allow removal of the radiator with the main fan shroud still attached; the A/C fan shroud, I found, was better detached before removing the radiator and left dangling - no clearance for it.
Coupla tips: the electrical connectors can get stiff with age - a spritz of silicone spray before wiggling, helps to get them off. Before you put the new one in, cut pieces of the cardboard box it came in, which just fit in the radiator frame and cover up all the fins - avoids gouges as you maneuver it into place. This is especially important if you attach the new bottom hose before installation, which *may* be necessary - the bottom hose clip location is often inaccessible with the radiator installed... without more, boring disassembly. Getting the new radiator into place while trying to route the bottom hose is where that 2nd person helps.
Good luck.
Rgds, George Macdonald
"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??
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    I have also found that it is also easier to remove the lower radiator hose where it attaches to the engine, and wait till the radiator is on the bench to remove the hose from the bottom of the radiator. bob
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You should check if your radiator fan and itsswitch are working fine. Never changed a radiator on a Honda but did it on a Ford and a Nissan no problem. It is easier than several other things you have done.I didn't buy new radiators with my old cars. I bought refurbished ones instead. And you should change the thermostat at the same time since you're not sure. You might also want to plus a garden hose into the system and rinse everything clean since you'll be changing the coolant anyway. They sell an adaptor that you can easily install on one of the hoses and plug a garden hose to rinse the system.
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snipped-for-privacy@aloha.net (Seven) wrote:

Chris, I won't be able to answer all of your questions but can offer some advice since I had a defective radiator on my car when I was a poor college student. I compared the price of a new radiator at the car dealership and a new radiator that was sold by a radiator repair shop located in that town. Needless to say, the radiator at the radiator shop cost about half as much as the radiator that the car dealership wanted to sell me. I also shopped at a junk yard but did not find any cars at the junk yard that had a decent looking radiator that would fit in my car. I ended up buying the radiator at the radiator shop. I could have easily installed it myself but the radiator shop owner installed it for about $20.00. He also installed a new thermostat. I also advise you to replace the water pump at the same time that you replace the radiator. The junk yards are now on a computer net work and might be able to get you a really great radiator for a low price. Some junk yards even provide a free guarantee on any products they sell--they just replace any defective product.
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snipped-for-privacy@nospamhotmail.com (Tom Wilson) wrote in message

Sorry, forgot to mention I had the timing belt and water pump changed July 2002 at Honda and only put about 12,000 miles on it since then, so I don't feel a need to change the water pump.
Thanks, Chris
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snipped-for-privacy@aloha.net (Seven) spake unto the masses in

<snip>
This does not sound like a rad problem at all. How's the coolant level? Has it been bled properly using the bleed bolt on the upper rad hose?
Do you notice the reservoir level mysteriously going UP?
If the coolant level is fine, it sounds more like something electrical, Like maybe the TW switch being bad, its wiring corroded or something else electrical.
--
TeGGeR

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I never checked this. I was going to after the new radiator installation because, like I said earlier, the damn radiator fins are disintegrating! So regardless of what's causing the problem, I need to replace the radiator. Just wondering if it could possibly be the thermostat that's really the cause of the problem. I guess it could be the TW switch, so I will check that after the radiator is replaced. Any tips on checking that?
Thanks, Chris
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snipped-for-privacy@aloha.net (Seven) wrote:
message

Chris, I am now wandering what made the fins on the radiator go bad. Do you live in a state that receives lots of snow? If so, I wander if the salt used on the road to melt the snow and ice managed to get on your radiator. Did you drive into some standing water on the road and did the water coat the front of your car? If so, that could explain why your radiator fins are now in bad condition. If that did not happen--it could be a factory defect. You might want to talk to the service manager at the local Honda dealership to determine whether or not there have been in recalls on your vehicle. You may be able to find that sort of information on the internet. Try this site http://www.alldata.com / also www.recalldata.org
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snipped-for-privacy@nospamhotmail.com (Tom Wilson) spake unto the masses in

This is normal. If you live in an area that gets snow, it's only a matter of time before the fins corrode away. Very common up here.
You have to lose a good chunk of the fins before cooling is noticeably affected, like a third of them. Usually you get a hole in the middle bottom of the rad that goes dusty and falls out. It's that "bottom-feeder" grille that does it.
--
TeGGeR

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snipped-for-privacy@nospamhotmail.com (Tom Wilson) wrote in message

I live in Hawaii, where there is salt in the air, as well as humidity. Could that be a reason for the corrosion?
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snipped-for-privacy@aloha.net (Seven) spake unto the masses in

Yup. When I was there in '85, it rained pretty much every day, usually at night. I was also surprised at the amount of rust on the cars there, until I realized it had to do with the salt sea air.
--
TeGGeR

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Well, you must have been on the windward side of some island. The west (lee)sides of the islands here are pretty arid/hot. Those who live further west and away from the ocean actually have nice, older cars. You'd be surprised at the number of "vintage" cars in really nice shape (for those that take care of their rides).
Chris
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snipped-for-privacy@aloha.net (Seven) spake unto the masses in

It's been years, so I don't remeber where I saw the rust, Must have been the windward side. We rented a Jeep and went around Oahu a few times sightseeing. I had never before seen such Hollywood-style waves until I saw the windward side of Oahu.

Yes. We stayed in Honolulu like most tourists. Saw lots of older Japanese cars especially, including a jacked-up Toyota pickup with the notation "Hawaii's Own Poi Pounder" in giant letters on the side (that one might have been on the big island...).
--
TeGGeR

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i agree with TeGGeR, this sounds like a low coolant problem, i had a very similar expierence, i would suggest topping off yuour coolant level and reserve tank before doing anything major.
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Hi,
Yes the coolant was low. Very rusty colored, too. I checked it yesterday before doing anything else. However, I still decided to go and replace the radiator and thermostat. I wanted to replace the radiator now as like I said, the whole front of it was pretty bad, all the fins had disintegrated. And I'd rather not get stuck someplace when it eventually goes bad. I put in a new thermostat as well, being that I was in there, as well as new hoses.
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|Do you think that the radiator is the root of the problem with the |symptoms I am having?
Sounds more like a cooling fan isn't coming on. Could be the fan, or the switch that controls it. May also be a relay in the circuit.
|1)    Is the work involved too much for a backyard |mechanic
No. relatively straightforward.
|2)    Do I need any special tools the average backyard |mechanic would not have access to?
A varied vocabulary is probably useful. Bandaids.
|3)    How much will a new radiator be (price range)?
Should be able to get it for under $100 Call around, prices vary wildly and it's a competitive market.
|4)    Should I purchase a Honda radiator?
There are only a few manufacturers, all are of good quality.
|5)    Can I do the job in a day? Will I need more than myself to do it?
One day should be easy. Do the hoses and anything else - fan motors? - at the same time.
|6)    Any other advice you can give regarding the specifics about |radiator replacement in Honda Civics of this vintage.
Use the steps listed in the shop manual or a Haynes. Proper sequence will keep you from doing something twice, orhaving to force one thing past another. see "vocabulary", above.
Good luck :) Rex in Fort Worth
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snipped-for-privacy@REMOVEtxol.net (Rex B) wrote in message

Nope, fans come on. See above.

Ain't that the truth, I got nice and cut up putting the damn thing in!

Took me 12 hours to do it, including chasing down the parts, lunch/dinner breaks, flushing and refilling. Damn tiring. My legs/lower back hurt from stooping over the fenders and front end working in the engine compartment!

I had a Haynes manual, which was just OK. I could have done the work without it, I think. I'd much rather like an official Honda manual, though don't know where to get one.
The damn A/C line hose got in the way of me putting in the driver's side fan. I scratched up the fins a bit getting this fan in with the tight clearances between the exhaust manifold, A/C line hose(s) and the radiator. This shouldn't affect the functionality of the radiator, should it? I also noticed that the A/C line hose is brushed up against the shield on the exhaust manifold. The A/C line hose has a plastic shield around it I am thinking that acts as a shield from the somewhat hot manifold shield. I didn't notice the proximity of the hose to the shield before, so I don't know if this is OK or not. Also, I didn't notice/smell anything burning when I drove the car to work this morning, so I have to assume it's OK. Thoughts on this?
So the car is running cool now, the temp gauge is 1/3, solid. It does not move at all. Awesome! Stop-and-go or straight on the freeway, everything's "cool". The fans are not coming on at all, 'though I don't know if I hooked them up incorrectly or if the engine is not hot enough for them to come on.
Thanks, Chris
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