New Radiator overheating - Help idiot on the loose

[KdkGrizz]

Hey everyone, So recently I changed the radiator out in my 82 Waggy to a PRC alumium crossflow. Installed is flawless kudos to PRC !! Anyhow, I also replaced the OEM cooling lines with steel braided lines. I ran the pressure to a B&M transcooler then out to the upper connection on the transcooling in the radiator, and the return line from the bottom fitting on the trans cooler on the ratiator. My particular Waggy did not come with an overflow bottel or recovery tank so I have installed a smal (YES I WENT CHEAP) overflow bottle.

Ok heres the issue. Before the new raditor, I rarely went above 200 degrees on the engine, and 155-160 on the trans. Now even short trips (No wheeling, just running around town) My engine temp is getting up to 222-225, and the other day the trans temp was nearing 210 which of course freaked me out. I have a large investment in that trans and do now want to fry it. I lost about a pint of fluid when I changed the lines, and radiator. I topped the trans off in case that was the issue.

What I am wondering I am running a 16psi radiator cap. Should I be running something more like an 18 to maybe 22psi cap? also should I be using a resevour vs an overflow bottle. Oh forgot to mention I am running a Derale dual speed electric fan. I have or had many plans this summer for the Old Waggy. Please any thoughts or suggestions. Maybe I am missing something that is right in front of my face......

[wiley-moeracing]

A couple of things, first is airflow through the radiator, aftermarket electric fans rarely pull enough air through a radiator, you can test this by running it with a large box fan in front blowing air into the radiator and see if that helps. I would suggest putting the factory fan set up with the shroud back on with a severe duty fan clutch. Just because it is a new radiator does not mean it is not clogged up internally from the factory, a temp gun would help diag. this. Then pull the thermostat and test it in a pan of water and see if it opens properly when heating up.

[KdkGrizz]

A couple of things, first is airflow through the radiator, aftermarket electric fans rarely pull enough air through a radiator, you can test this by running it with a large box fan in front blowing air into the radiator and see if that helps. I would suggest putting the factory fan set up with the shroud back on with a severe duty fan clutch. Just because it is a new radiator does not mean it is not clogged up internally from the factory, a temp gun would help diag. this. Then pull the thermostat and test it in a pan of water and see if it opens properly when heating up.

Sounds like a good plan, except I recently gave away my factory shroud ugh. In changing the thermostat should change to a different temperature range as well?

[Full Size Jeeper]

Are you sure the electric fan is not running backwards. Also if you had to reverse the fan, you also have to take the fan blade off, and flip it around on some models. Read the directions. I'am not trying to be a jerk, good luck.

[Kaiserjeeps]

What Wiley said. If you have the factory fan put it back on. If you don't have one then go to Summit and take your pick. Nice 7 blade fans of all sizes. Electric fans contrary to popular belief are not the shizzle. They just don't move the same air as a big ole fan.

[Ristow]

yeah,the electric fans gotta go. the radiators on these are small from a surface area point of view. the fan needs to be making a low pressure zone behind it at all times.



changing the radiator cap pressure rating will do nothing.

[letank]

X2 as above, electric fan do not do well with V8, even BMW and Benz V8s are running mechanical fan with fan clutch.

Even without a shroud it should be fine. You can test in and out temp at the radiator to check a proper temperature drop with a non contact thermometer

[rocklaurence]

Check the fan direction by putting a piece of paper up to the radiator [weather the paper is sucked in or pushed out will tell you]. Also, make sure that your lower suction hose isnt collapsing. There should be a large spring in the bottom hose to support it.

[KdkGrizz]

First thing, I checked. and did not take your comment as being a jerk. I appreciate all comments.

[Tanker]

Block flush,heater core flush both ways. Small hole in thermostat to help get air out.

[KdkGrizz]

Went back to the mechanical fan and burped the system went to 16 psi cap and drove it hard for about an hour. Never went above 195 even with a/c on. Trans temp did get up to 170. When I pulled back in to the driveway, and I let it sit and idle, engine temp stayed steady at 195-200. But trans went up to 180 can’t figure that out. Trans is fresh, new radiator with integrated cooler, and a separate trans cooler up front. Used the temp gun on cooling lines 155 on both lines. My trans temp sending unit is on the trans not an inline type. This one has me scratching my head.

[rapom]

Put your transmission in neutral and check the temp. 727 don’t circulate fluid in park.

[KdkGrizz]

Put your transmission in neutral and check the temp. 727 don’t circulate fluid in park.

Thanks. Yep that’s what I did. I am thinking that the sensor being on the rear servo test port might be the issue. Considering putting a second sensor on the cooling line to the trans.

[rocklaurence]

I run all my Trans fluid through an Aux cooler without going through the radiator. They run approx 160-180 temp'. Dont be concerned unless the trans temp reaches 220+.