Aftermarket bumpers and Engine/Transmission Temps

[thezentree]

I put an aftermarket winch bumper on my 4Runner early this year. I like the design because it tucks up really close to the front end and isn't super heavy. However, now that it's gotten into the hotter months, I've noticed that my coolant and ATF temps are higher than they used to be. Coolant not significantly higher, but ATF seems to have a hard time cooling once it gets to about 180 (it does fine at highway speeds). It's almost like my cooling system has a harder time dumping heat now.

Have those of you with aftermarket bumpers noticed a spike in engine and/or trans temps after installing the bumper? I am concerned that I'm just not getting enough airflow through the bottom half of my radiator.

A new radiator hasn't improved things and the fan clutch seems to lock up pretty well when it's hot, but I do think it's the original clutch. Am going to try an aux trans cooler when I have time to work on it ...in August.

 

[silver4est]

lets see this bumper

 

[apohl17]

So I noticed a definite increase in temps compared to stock, but I can't say I can narrow it down to when I installed my bumper. My satoshi is a pretty fine mesh, and I don't have the kind of airflow there anymore compared to what it was before. Just recently I replaced my thermostat and did a coolant flush, that put my coolant temps back down to perfectly normal (180-190) but if I'm pushing it up a long hill for an extended period of time without overdrive on, I'll see atf temps peak to 200-215 and once I get over, stabilize in the 190-200 range. It's significantly higher than the 160-170 range that is desired.

 

[JohnMc]

Well, that is blocking off roughly half the airflow to the radiator that the stock configuration has:

And there's definitely radiator down lower there that takes advantage of that airflow:

Not necessarily saying the truck can't cool itself through the grille opening alone - like most modern cars it's pretty overspecced in cooling compared to older marginal cars. But it's certainly possible that it's making it run a bit hotter.

 

[aontkos]

The Tacoma ARB that a lot of us run seems to cover a similar amount of the grill/radiator as your setup, and it doesn’t seem like many people have attributed increased operating temperatures because of it.

I’ll keep an eye on this thread. I have a newish (<30k miles) radiator, thermostat, water pump, hoses, etc. and I’ve noticed that my truck keeps wanting to run at 195-205F on the highway with the A/C on. Around town and without A/C it’s fine. I don’t remember it doing this last summer, but maybe it’s hotter this year and I’m doing longer drives more often.

 

[MStudt]

I'll start by saying this is NOT a problem with Coastal's bumper!

You reduced the air flow to the radiator when you switched your bumper. Given the trans cooler is in the bottom of the radiator, it'll heat up as the coolant does. The trans temp may also increase a bit more since it's now completely blocked from most of the air flow.

I didn't see a drop in mine at all, but I'm running an external cooler that hangs behind the grill.

Mike

 

[JohnMc]

I have a 4Xinnovations front bumper on mine. It has a couple of holes in the front part. Possibly for winch access(???) although in the case of my Zeon, they don't access anything of use on the winch. But it does allow some air in to the lower half of the radiator.
Before installing the winch:

It's a manual trans though, no trans cooler.

 

[nissanh]

Air flow to the bottom half of the radiator is quite covered with the aftermarket bumper. Any issue with your AC? You can add an external transmission cooler if you want to keep the bumper. How about making few openings in the bottom plate below the winch mounting plate?

Andrew White on 4Xoverland once showed how two massive front fog lights can change the engine coolant temperature.

 

[my92t4r]

i have the ARB and with an external cooler and my temp stay around 150F unloaded and goes up to 190 uphill or with a haul.....

I also mod a BMW brake air duct from those holes in the bumper to direct more air flow to the cooler :banana:

 

[thezentree]

I'll start by saying this is NOT a problem with Coastal's bumper!

You reduced the air flow to the radiator when you switched your bumper. Given the trans cooler is in the bottom of the radiator, it'll heat up as the coolant does. The trans temp may also increase a bit more since it's now completely blocked from most of the air flow.

I didn't see a drop in mine at all, but I'm running an external cooler that hangs behind the grill.

Mike

Yeah, agree. I didn't want to say who made my bumper since I think it's probably an issue with most, if not all, plate bumpers.

Did you plumb your ATF cooler on the hot side or cold side of the radiator? I've got a B&M supercooler sitting in a box on my workbench but I've got so much travel going on for work that I haven't had a chance to mess with it and won't for a while.

 

[thezentree]

Air flow to the bottom half of the radiator is quite covered with the aftermarket bumper. Any issue with your AC? You can add an external transmission cooler if you want to keep the bumper. How about making few openings in the bottom plate below the winch mounting plate?

Andrew White on 4Xoverland once showed how two massive front fog lights can change the engine coolant temperature.

AC seems to be working fine. I haven't noticed it not blowing as cold.

I did cut a few holes in the back of the bumper (the angled skid plate has space behind it where air can pass through) but it's not made much difference. I planned on cutting some holes in that angled plate, but I'd have to do it with a hole saw and a grinder cutoff wheel, and I don't think I could make it look as good as I would want it to.

 

[4Reak Show]

I have the exact same bumper on my 2nd gen. (Which has a SC'd 3.4 stuffed into it) and I was pretty concerned with airflow. I emailed the builder and was assured it has never been an issue... I don't know how much field research was done or whatever but that's the response. I still wanted to have piece of mind so I added a bunch of specific holes to the rear plate of the bumper to match 1) the holes in the very front of the frame crossmember and 2) the gaps between that piece and the one above it where the stock grille would have been open.

7 1" holes on the bottom and 2 1"X 4" slots above those.

I still have noticed a little more activity on my temp gauge but nothing in overly concerned with. And I've gone up some good hills in 80-90 degree heat. Mines also a manual so this entire post may be irrelevant

 

[MStudt]

Did you plumb your ATF cooler on the hot side or cold side of the radiator? I've got a B&M supercooler sitting in a box on my workbench but I've got so much travel going on for work that I haven't had a chance to mess with it and won't for a while.

I put mine on the cold side. It's pretty easy, and one less thing to worry about.

Mike

 

[mtbtim]

I have noticed higher coolant and trans temp running a CBI hybrid bumper and winch on my 98. It's pretty obvious the aftermarket bumper and winch does inhibit air flow through the cooling fins of the radiator and aftermarket trans cooler I have. As a result, I have seen higher temps with this rig compared to my 2000 which is pretty much stock. I also think the higher temps I see are due to the fact that my engine and trans are working harder because I'm carrying around approximately 700 extra pounds all the time with the bumpers, winch, rock rails, full belly armor and roof rack. The strain on the drivetrain is mostly evident when climbing grades and my rig struggles to maintain speed.

Due to the higher coolant temps, I decided to start running a Stant 170 degree thermostat at the recommendation of my friend Anwar. It was a good move because my coolant temps are now much better especially when climbing steep grades in high ambient heat.