Keepitgoin

Hello. New member here.
I removed the cap from my radiator and the bottom plastic piece broke off and fell into the radiator. This part is maybe the size of a dime. The broken part scooted out of way and doesn't seem can directly retrieve it.

Should I be worried about this? Worried enough that I should remove radiator and try to flush it out?
I've not started cat yet...

​​​​​​97 4 cyl EX Auto
​​​​​​Thanks for advice!
Paul

lothian

Your call. I get your concern with this sort of thing: A sufficiently small piece of plastic could finding it's way to—and block—a port in the jacket. Who knows if that would ever happen; who knows if it'd actually cause problems if it did. There are no assurances to be offered here.

The upshot is... yanking a radiator from an Accord is not a difficult job at all. And with that thing out you can easily evaluate the condition of your coolant hoses and A/C lines, inspect the fan motors and misc. plastics; inspect for oil seepage; and consider adding an external transmission filter (advisable) and replacing the front engine mount (if necessary); and flush/refill the engine with fresh coolant nummies.

The downside is... despite your exertions you risk damaging the radiator with all the jostling, and the plastic detritus might not be retrievable.

Keepitgoin

Thanks, Lothian.
Good point that the old car (but under 100k miles) would benefit from going over the cooling system.
And today I took distributor out to change seals due to oil leak and found a bubble in water hose beneath so will be opening the cooling.
(I'm also going to post on distributor problem.)

I think all parts are original. What do people normally replace in a cooling system refresh?

Is the a DYI on upgrading to the in line transmission filter?

Paul

​​​​​​

lothian

Folks pretty much replace just the coolant during a routine cooling system refresh, and the Honda Service Manual (HSM) specs changing it every 75k miles. The HSM also sez to check hoses every 45k. The water pump isn't a specifically scheduled item, though prudent folks replace it when performing a 'timing belt job' at 105k. Thermostat and temp sensor typically get replaced if/when the car starts consistently running above normal engine operating temp—~195° on a 4cyl, I think. And that's pretty much the inventory of coolant system whatnots. BTW... Failure to purge the coolant system of trapped air during a refill may cause engine idle problems (i.e., hunting a/o surging) so it's worth doing this job correctlyusing the tool specifically made for it. A handful of YouTube videos demonstrate the process.

Installing an external transmission filter is definitely within the scope of a DIY job. The filter lives in the space at the bottom of the radiator for ease of access, and gets cut into the transmission-to-radiator ATF cooler hose. I replace the filter at the 40k-miles-three-quart-AFT-fluid-drain. A handful of YouTube videos demonstrate the installation process.

Fitz Williams

iTrader: (1)

A word on transmission coolers. I have used a number over the years, all Hayden ones. I have used this:

And this:

And, finally, this:
Actually, one of the smaller ones, but as large as I could fit in front of the radiator. This type worked much better than the first two and is easier to mount. I threw the other two away.

nicolaselias

Honestly any cooler is better than no cooler. But yes the bar and plate ones are superior.

I use the magnefine in-line trans filters (3/8") and have done so for years. Been great on my older vehicles

Keepitgoin

Tech I talked to at my Honda dealer also thought having small piece loose in radiator was bad idea.
So I did pull the radiator, turned it upside down and washed out the problem plastic. I will feel happier in any case.

I will install a raybestos magnetic tranny filter. I didn't see Magnafine product for comparison. Tranny fluid, partially changed two years ago was not a pretty red. so sounds smart.

I wasn't necessarily planning on putting in a auxiliary tranny cooler as the car isn't run very hard. But I'll certainly consider if that is current wisdom...

And will replace top rad hose and "Hose A, Water Inlet - Honda (79721-SV4-000)" which was damaged by oil from distributor leak. 25 year old bottom hose looks fine.

Lothian, I will give the front engine mount a close look for cracks. Job doesn't seem to me to improve access to other mounts

nicolaselias

As far as I understand it, the raybestos and others were replicas of the original magnefine. Any filter is better than none for sure, so go for it.

Re trans cooler, if you are easy on the vehicle you dont NEED one but you should make sure your radiator is in good condition

Re top hose, i changed mine the other day using the gates replacement I think.

Fitz Williams

iTrader: (1)

I have a temp gauge to measure the trans fluid temperature. It seems that the more shifting the trans does, the more it heats up. Around town in heavy traffic is bad, but the mountains are worse.. At least the way I drive.

nicolaselias

Your assumption is correct fitz, shifts do generate more heat, as does torque converter slip. The main thing is finding a sweet spot where you are not lugging the engine but the trans is happy to be in one gear as much as possible for whatever type of conditions you are driving in.

Keepitgoin

Thanks for the input. I guess while I have all apart, I will put in a transmission cooler as well as the filter.

This looks like the cooler discussed above, which is size Hayden seems to recommend for sedans. Or could go with these bigger one.


Any advice -or picture- on how to fasten it in place?