Hello all,

I al currently in the process of installing a coolant pressure gauge. It may not be helpful but because I am a nerd and preciously a chemical operator I wanted to monitor the pressure of the system whilst running.

In tandem with the coolant pressure gauge, I decided to install a water temp and oil pressure gauge.

The best place to tap in was the radiator to expansion line. My plan is to utilize the 5/16th transmission hose swap the forums recommended and tap in right by the intake hose/MAF.

I used the Glowshift MaxTow Gauge and purchased the WRX fuel line sensor adapter as it utilizes 5/16th hose barbs.

My thought was that if any fluctuation of pressure, ie increase, would be a qualitative way to identify a cracked block/slipped liner generating escaping gas from combustion. Decrease in pressure may not be as valuable as it either means long term decrease in standard operating pressure and or massive coolant loss. By the time observed coolant pressure is observed it may give a slight window before it is detrimental.

If it provides value and I observe any valuable data I will follow up and comment on here

 

I haven’t heard of anyone doing this but it could be valuable information. I’m looking forward to hearing your results.

 

The pressure cap should vent at 140kpa, so not sure you will ever see it spike above that. You can plug the cap with jb weld if you want to see how high it goes, but your radiator tank and expansion tank are not rated for significant pressure above that and I have cracked both.

 

Yeah I was under the assumption that it wouldn't be helpful knowing it relieves at the pressure at which the radiator cap is rated.

I wanted to verify the radiator was indeed releasing pressure if and when the coolant pressure did increase towards the radiator cap pressure

So I was troubleshooting a cooling system with a leak. As of right now I believe I have button that up by replacing the heater hoses and spring bands.

I drove it down to my local watering hole to celebrate and see if the coolant system was operating as it should.

With a denso replacement radiator cap rated to 14psi I observed no puddle under the vehicle after driving and city driving temps in the range of 177-185. The coolant pressure operated from 7-10 psi in the temperature range of 175-185 and remained constant. Whilst the temperature of coolant remained in the range of 180-185 the pressure remained constant at 8-9 psi. It creeps to 10 as it gets 185+

As I lost some coolant doing the hose swap and installing the glowshift pressure and temp sensors my coolant level was below the cold line of my carrs version 1 expansion tank after topping it off to the cold line. The level was roughly at the bottom of the sight glass.

As mentioned in a previous post I am assuming the inline mod lowers the required volume of coolant required. So I am not too concerned.

My oil pressure was satisfactory I believe. I don't remember what it was at cold idle but at warm it was 50psi.

After the engine cools and I am able to verify the system is water tight I will provide more information on the warm up and build up of pressure observed during idle and the behavior of the pressure as the temperature increases to operating temp with the inline mod.

 

50 psi is very good for warm pressure.