I've got engine oil leaking from the bottom left corner of my radiator. I assume the oil runs to a heat exchanger in the radiator. I can't find a separate part for that.

Does anyone know if I have to order a whole new radiator or if I can order this part separately?

Thanks,
Tony.

Are you sure it is oil and not trans fluid? A lot of transmission coolers use the radiator to drop temps.

If it is in fact your trans cooler or power steering cooler and it is an obvious leak caused by a cracked nipple or something that will not effect the integrity of the radiator. You could consider an auxiliary transmission cooler. They typically get attached to the radiator. Just omit the integrated heat exchanger and plumb into the auxiliary.

I have worked on several of these vehicles. I can't recall them using an engine oil cooler in the radiator. But it does have a transmission cooler in the condenser, in front of the radiator. (The refrigerant and trans fluid don't mix. If you look closely at the condenser, the tubes and fins for the two sections have different sizes and spacing.) These, I have seen leak. If it is just seeping, the otherwise dark red transmission fluid can pick up dirt and look more like oil.

Double check the fittings to be sure they are tight. That would be a cheap/free fix.
Otherwise it's probably the cooler itself.

A little follow up, and yes, it is transmission fluid. I guess a popular fix is simply to bypass the factory cooler and install an external one. I guess this is not and uncommon problem.

I guess we'll do as you suggest and hack the lines off where they are metal and tap into the system from there and route the lines to the new cooler. Maybe we can mount it in front of the old cooler.

Tony.

Might just be bad o-ring on the fitting, and be an easy fix.

I had that motor in my old Liberty. The radiators had plastic fittings and they are prone to cracking. Assuming its the same in the Commander, make sure you inspect or have all the hose connections inspected.

Todd

quote:

Originally posted by benny6:
A little follow up, and yes, it is transmission fluid. I guess a popular fix is simply to bypass the factory cooler and install an external one. I guess this is not and uncommon problem.

I guess we'll do as you suggest and hack the lines off where they are metal and tap into the system from there and route the lines to the new cooler. Maybe we can mount it in front of the old cooler.

Tony.

I think ALL problems with that era of Jeep non-wranglers are fairly common.

Totally bypassing the old cooler will overcool the transmission. In cold weather it may never get up to operating temperature.

Well we installed a new cooler after a 500 mile round trip where my original cooler was leaking. The swap went fairly trouble free but I was concerned because when we cut the lines, no fluid came out of the hoses at all. Maybe a few ounces.

I figured the transmission cooler must have really leaked a lot. So after installing the new cooler, I put in 2 quarts of fluid and we took it for a test drive.

After driving for 10 minutes, there was smoke coming from under the hood. There was no leaking from our work but there was transmission fluid all around the dipstick area. I guess I really overfilled it. I figured for all the transmission fluid I must have lost, plus a new empty transmission cooler, two quarts shouldn't have been too much. I guess I was wrong.

I The transmission worked fine. What is the likelihood that I damaged it? I'll crack the line in the morning and drain a quart and drive it for a little while and see what happens.

Tony.

quote:

Originally posted by egregore:
Totally bypassing the old cooler will overcool the transmission. In cold weather it may never get up to operating temperature.

I did not see this comment until just now.

Tony.

quote:

Originally posted by 220-9er:
Double check the fittings to be sure they are tight. That would be a cheap/free fix.
Otherwise it's probably the cooler itself.

There is no factory cooler. Aux radiator cooling systems for transmissions are usually installed on vehicles as part of a tow package.

Wash it thoroughly, run it, and identify the actual source of the leak.

Overservicing the transmission can damage or destroy the transmission, cause seal failure, etc. It's the reason that some manufacturers now remove the transmission dipstick. Oil shouldn't be added by the quart in a transmission; it shouldn't need any, but is usually added by the fluid ounce.

If there's no fluid in the cooler, then you may have a blockage, which should be investigated. If the transmission fluid level isn't low, don't add more. You could end up severely damaging the system, and if it's so overfilled that fluid is coming out the dipstick, immediately stop driving, drain the transmission, inspect your magnet and check the fluid for metal, and replace with fresh...in the proper quantity.

Bypassing a cooler won't cause a transmission fail to reach operating temperature or cause the engine to be overcooled. The cooler is what cools the oil. Bypassing a cooler prevents the cooler from cooling the fluid...bypassing doesn't cause fluid to get cooler.

Probably a leaking fitting or rusted pinhole in the line.

The cooler is inside the radiator end cap . So, if the cooler was leaking, you'd have fluid in the coolant. The nipples go through the plastic end caps, which are held in place by a couple of nuts. Then the lines connect directly to the cooler nipples. So if its leaking outside the radiator, it has to be a leaking fitting or rusted line.

The factory cooler was plastic and was leaking from the drivers side where there are no connections. The factory lines were leaking too but not at the connection points.

There are no more leaks in the system.

Tony

quote:

Originally posted by sns3guppy:

quote:

Originally posted by 220-9er:
Double check the fittings to be sure they are tight. That would be a cheap/free fix.
Otherwise it's probably the cooler itself.

Bypassing a cooler won't cause a transmission fail to reach operating temperature or cause the engine to be overcooled. The cooler is what cools the oil. Bypassing a cooler prevents the cooler from cooling the fluid...bypassing doesn't cause fluid to get cooler.

I think he meant bypassing a cooler by installing an external cooler.

Tony.

So I pulled the pan and I don't see any shavings. I last had the transmission serviced around 2013.

What do you think?




Tony.

Looks pretty typical to me. A little sludge-like (actually the ferrous metal elements of clutch packs) buildup on the magnet isn't a problem. An excessive amount, or pieces elsewhere in the pan, now that would be bad.

Thanks. I just finished it up. I put in 4.75 quarts as a starting point. Dipstick reads 35mm but I don't have the actual temperature. I only drove it about 5 minutes but let it idle for a long time. No more leaks so far.

I'll have to let the rest of the fluid that spewed all over the place burn off and keep an eye on it for a couple of weeks.

Tony.