Heater Core Shenanigans

[The_Bishop]

Once the weather turned cool, I noticed that my heater output has been... less than good. On really cold mornings, it was barely lukewarm. The hoses going to the heater core weren't particularly different in temperature, either.

On this particular morning I was headed to the gym. Decided to check the coolant level, make sure it's not low.

Coolant level is good. Now, as I'm looking in the engine bay I see the heater core lines at the water pump. Yeah, I'm going to the gym but right behind me on the shelf is one of those air/water flush guns. The hoses are right there... how hard could it be?

So, I stuck a pan under the car, pulled off the heater core hoses and jammed some stoppers into the water pump ports to keep from losing too much coolant. Set up the flush gun to reverse flush the core. Burped a little air through it to empty out the core, and looked in the pan. Some brown chunky stuff, not too much. Once I had the core essentially blown clear, I let the air flow and opened the water valve on the flush gun, which jams a lot of turbulent water and air through whatever you're flushing, hopefully clearing it out. Some of it even drained into the pan!

Checked the pan afterwards and had more chunky stuff that was pretty soft, but the water was really, really murky. The coolant in the radiator is pretty new and clean looking but apparently the heater core was moonlighting as a filter and caught all the 'stuff'. Back flushed it some more, then flushed it the 'correct' direction until it ran clear. I only got about 10-12 gallons of mucky water on my garage floor, so success?

Afterwards I put it back together and filled the radiator. Backed it out of the garage to survey my horrendous mess and also to let the car run and warm up. Kept topping up the radiator as the level dropped.

In short order I had hot air from the vents, awesome. As I squeegeed the puddles out of my garage I let the car run for a bit, to fully warm up and completely fill the radiator once the thermostat opens.

I noticed another thing now. I had fixed another 'problem' I had been scratching my head over for a while.

Prior to this, while driving the car the temp would sit essentially right on the thermostat (160). If I stooped and let the car idle for a few minutes, the temperature would creep up to 190ish, the fans would kick into high gear. It would never overheat, just creep up and hang around 190-195. I had replaced the thermostat and drained/refilled the coolant in the hopes of fixing the problem with no success.

Well, now it doesn't do that. At all. It will get to the fan low speed temp, the fan will kick on, bring the temp down and kick off. It never hits the high speed now.

I'm assuming the cooling system needs the flow from the heater circuit to get the thermostat to work right? The 'out' from the water pump to the heater core is on the engine (hot) side of the thermostat, and the return is on the inlet/radiator return (cool) side of the thermostat. With the core nearly blocked off that flow wasn't present. I'm assuming that this was causing a delayed thermostat opening at low engine speeds.

Anyway, wall of text to say that I flushed my heater core out to fix my low heat output and inadvertently fixed a low-engine-speed heat creep issue as well.

I was only and hour and a half late to the gym.

[sweetbmxrider]

And here I thought it was going to turn into a heads/cam build

[The_Bishop]

Ah, soon enough; kind of thinking about very late winter/early spring. Life has been a game of catch up for the last year and a half with my Dad passing and moving my Mom up from Florida.

I finally decided on a camshaft to run, the Scoggin Dickey LS6 Power Max PLUS. They've got a video here that shows it dyno'd in a stock 5.3 with a TBSS intake and a 92mm throttle body. In the 5.3 it made 448HP at somewhere around 6300 and 433 ft-lbs at 4600, with a pretty respectable 375 ft-lbs at 3500, which is right where my torque converter stalls. Not looking for 'Max Effort' just a decent power gain and longevity.

Specs are: 220/222 @ .050, .570 lift, and a 112 LSA with +2 ground in.

Trying to avoid spinning the engine to the moon. In a 5.7 with the LS6 top end I shouldn't have to shift higher then 6200 or so which will keep the rods inside the block and the 4L60E's parts from littering the road.