So my gf called me last week and told me she heard a loud pop under the hood. I went to go look at the car and noticed that the upper radiator hose looked like it was deflated and collapsed. But the weird thing was the coolant was like a milky thick texture I knew something was wrong. I started with the basics, I got a new upper radiator hose and replaced the thermostat at the same time since I was there. I flushed the system 3 times. Put new coolant in the car and kept an eye on it for couple days didn't noticed anything in the coolant. Last night gf comes out of walmart and notices that there is weird looking coolant underneath the car again. At this point I knew something was wrong and oil was getting into the coolant some how. I knew it wasn't a head gasket because compression was dead on and car was running great. I took it to a shop to have them diagnostic it. They told me that the transmission oil cooler needed to be replaced and they suggest replacing the heater core and radiator at the same time. But could get away with just replacing trans cooler. They told me they wanted $390 which I thought was extremely high. So I told them let me think about it and I call you back. I called Honda to see how much the part was and after looking they told me that the car didn't have a oil cooler. At this point I'm now thinking hmmmm, what the hell is going on here. After doing some poking around it appears that the US accords have the trans cooler built into the radiator. So I'm thinking the shop said for 390 they will replace the trans oil cooler but not the radiator. But the car dosen't have a external oil cooler so wth are they going to replace. I suggested to my gf that we replace the radiator flush it multiple times and make sure that the trans has the proper fluid level in it. What do you guys suggest before I start on this project?

 

What year Accord? Automatic I assume, because they're talking about the oil cooler?

Strange that they "suggested" replacing the radiator, because the ATF cooler is inside the radiator. When that line leaks, you get ATF mixing into the coolant. And vice-versa.

Wanna DIY?? Get a new radiator. Also get a pile of Honda ATF so you can flush the crud out of the transmission when you're done. Search for ATF flushing.

 

Def want a do it your self. Sorry it's a 2003 honda accord Ex V6 Automatic. Trans flush oh geez that sounds scary lol.

 

No the trans "drain and fill"/flush is the easy part of the whole thing.

New rad, might as well replace the upper and lower hoses, think about a new thermostat, IMHO get new trans cooler line - sold by the foot at a good parts store, do not use fuel line....must be rated for trans cooler use. About 6~9 quarts of Honda Trans fluid.

Please only use Honda trans fluid....either get it from the dealer or the only parts store I've seen it in is carquest.

Just me.....Once you have it all out...rad, hoses off, t-stat out....turn the key to on (not start) and set the heat to max heat - opens the heater core.

Garden hose into the t-stat housing - low pressure. Then switch to the other......want to see the water coming out "clean".

Get the cooling system all back together and then be sure to bleed the air out of it....Honda's don't like air in the cooling system....yes the refill with 50/50 still applies.

Verify no coolant leaks...top of coolant as needed.

Trans. Warm the trans/engine up, shut engine off. Remove the trans drain bolt, let it drain. Wipe off the drain bolt. Install drain bolt. Re-fill trans....take a short drive....~15 minutes? Repeat this at least one more time (that would be around 6 qts of trans fluid) or do another drain and fill ( add another ~3 qt's of Honda trans fluid)