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Do you have a radiator shroud on? Coolant to water ratio? Just trying to establish the basics. Maybe also remove the Tstat and put in a pot of water, bring to boil and verify its opening all the way?
I know they would run these cars pretty hot from the factory... up around 220 IIRC. But running that hot with a 185 Tstat seems like something is off.
I found after my rebuild that the cooling chambers in the block and rebuilt heads released a lot of brown gunk. It took three changes to get most of it out. That stuff clogged up my radiator which apparently was already weak. I flushed the radiator out that helped a lot but car still gets too hot. I just got a better one and am waiting to put it in.
The other thing is to make sure you bled the cooling system. Though it sounds like you ran it for a while without the cap, so you may have already done that.
What's your timing? Retarded timing will cause it to run hot.
What's your idle speed and approximate air fuel ratio?
You sure the fan clutch is good?
220 is basically normal operating temp. How sure are you that this aftermarket gauge is correct? If you are seeing 215 with a laser temp gun - that would be normal.
I highly doubt that dual electric setup would move significantly more air than the shrouded mechanical fan. At any rate if it's overheating with the mechanical then moving more air probably isn't going to entirely fix the situation.
What's the coolant look like? Does it look like chunky diarrhea?
I think you will like the results after you install those electric fans, my new duals made a world of difference over the stock single electric fan. I just got home from a 90 minutes cruise around town and the temp stayed around 195-200 in stop and go traffic. Check back after you install them.
The other thing is to make sure you bled the cooling system. Though it sounds like you ran it for a while without the cap, so you may have already done that.
How hot does it get when driving at speed?
Originally Posted by Jonnydepp
Ok guys, took Tstat out and it opened up nice and full in boiling water.
wanted to see if it would be any different driving without a tstat and it stayed cooler for longer but still eventually got hot.
looking at a set of electric fans/rad from some guy parting out his third gen
how much would this help drop temp?
Shrouds like that can defeat the purpose of a shroud. Fans find it easier to pull air from those slots than through the radiator...
Yeah - it should be solid and you should block off the sides of the radiator with some foam, etc. The fans can pull air from the engine bay around the sides of the radiator instead of from under the front of the car where the air is cooler.
The question of what temperature the engine runs at while driving at speed didn't seem to get answered. This could help determine whether we're dealing with an airflow problem or a cooling system problem.
40* temp drop across radiator at idle looks real decent-seems some sort of coolant flow bollox with the new heads and intake could be causing a hot spot right where the gauge sender is.Fan shroud is not 3rd gen-looks like it may be a B or G body part
How far away are the blades from the inner diameter of the shroud? Hard to tell from the photo, but it looks like there's quite a big gap. Too big a gap will result in reduced suction ability for the fan to pull air through the radiator. I don't know what the right number really is, but intuivitely I would think I wouldn't want more than 1/2" from blade tip to shroud. On my Ford Taurus electric fan that I put on my 2nd gen, the blade is about 1/4" away... but I'm running a stock water pump, 180F thermostat, a radiator that most would call a "cheap reman" (aluminum 2 row with plastic tanks) and it has absolutely no problem cooling a ~400 hp small block in 100F weather in traffic with the A/C on... in those conditions it'll get to 190 sometimes, but the high speed will come on and knock that back down in pretty quickly.
Instead, get a truck (18-wheeler) mud flap. It'll be somewhat foamy rubber about 3/8" thick. You can find em at any 18-wheeler truck stop along any major freeway. Looks like for you it'll be the 95, 87, or 40. Just hit the road and look for a Blue Beacon, Fruehauf, etc. that caters to commercial traffic. If they don't have it they'll know RIGHT WHERE to send you that does. Cut off a strip a few inches longer than the full length of your radiator lower core support, and wide enough that it comes within an inch or 2 of the ground. Bolt it to the core support with a piece of about 1" aluminum angle and about 6 bolts w/ BIG washers holding the rubber to the angle, and the angle bolted to the car with all of the factory hardware.
It's thick enough to hold its shape under any kind of realistic air pressure, but flexible enough to bend out of the way when you smack a parking lot bumper or driveway ramp, WITHOUT destroying itself. And best of all, YOU can DO THIS, for less than $25 and a half-hour.
Yep. No bottom half of shroud, and no air dam, either. Double whammy right there. Get them on there and you will be good to go. I bought a new GM air dam from Amazon for $65 + shipping.
08-15-2020, 11:17 AM
