914 V8 cooling, overheating issues Options

[John2kx]

Howard,

I run a Renegade cooling system and have had overheating issues along the way. Most were due to problems caused by myself. I'll post some pics of my system and be glad to share what I have learned the last year and a half.

First pic is of water sender location. I actually run two gauges. The two brass fittings are my temperature monitor points. Since the water from pump is routed into block, to heads and then to intake prior to moving back to radiator, the intake is the preferred location of sender.

John

[John2kx]

Howard,

Your pics posted fine. Some took a long stare to figure out what I was looking at........suggest in the future starting with a overview of area your trying to pin and then zooming in a bit for the next shot.

Good news! Your cooling system looks better than most I've seen that weren't designed by RH.

1. I only notice one fan up front and thought you mentioned one (of two) staying on all the time and the second was manually controlled. Am I missing something here? I would like to understand for sure what turns your front fan on. Trace the wiring from fan motor. You should see power source and if supplied with a thermo switch mounted in radiator, a second set of wires from this switch to fan motor or to a relay or similar device that connects back to fan motor.

2. I think you have a source of air entering your system the way things are configured. The expansion tank mounted in left rear of engine bay is a good fill point, holds lots of water and is mounted higher than radiator and intake.......all good. What I see wrong here is that if you fill that tank full when car is cold, as water temperature rises and expands, there is no place for excess to go but out overflow line. I see no overflow tank and it appears overflow line discharges to ground. What you want is a tank for the water to discharge into and then as water temperature cools (contracts) a vacuum is started that will suck water from overflow tank back into expansion tank. Without overflow tank, when vacuum occurs, you will suck air back into system everytime you run through a heat/cool cycle. I believe for less than $10 you can fix this problem. Note: I usually see about 1 qt. of water added to my overflow tank when car is hot.

I'll attach a pic of how Renegade (RH) makes this happen. The small fill port acts just like your large expansion tank. The plastic tank is the overflow collection point. Note: overflow tank is mounted as high as possible and close to expansion tank to eliminate air pockets from enter cooling system.

I don't think the fans mounted to engine bay help. They can't hurt and are already mounted. Up to you if you want to remove them.

Sensors: the picture was dark but what I see is tapped into a oil source near distributor. I have something similar but use a single sensor with two outputs. One for oil pressure gage, the second goes to idiot light. Look at front of intake (either side of thermostat housing) for water temperature sensors.

I would not put much faith in measuring exterior of radiator, thermostat housing, hoses etc. when trying to determine true water temperature. My experience with a $175 infared gun measuring these points proved useless. To prevent risk of damaging that new engine, I'd advise a second method of reading true water temperature.........buy another gage.

You should have found how to bleed system of air from previous posts. This is often overlooked by most but a important part of procedure to ensure air is removed.

John