Search the Community
Showing results for tags 'diagnosis'.
Hi, I've been dealing with an overheating behavior in my YJ 1989 Wrangler (4.2L with all emissions control hooked up except pulse air system, Carter BBD, Auto Trans). Long time ago I've replaced cooling fluid, It was 100% tap water that is the worst choice due to corrosion; so I decided to replace it by an ethylene glycol mix as you can find them ready to pour into your cooling system. I don't know if the coolant was poor quality but immediately after replacing the fluid I was getting the engine overheated. Perhaps it was air trapped in the system as the guy replacing the coolant did all the procedure really quick with the engine still warm... Well I had to go back to water again and the issue was solved. No more overheating during next days. Then I went wheeling several months after, when stopped the vehicle heared something like a pressurized air leak, it was the hose from the thermostat housing to the intake manifold, was cracked and ended up blown after I pulled it. So I shortened the hose and reinstall it again. Got home with overheating issues again. Bought all new hoses, including upper and lower radiator hoses. Heater was disabled so former owner plug the nipple coming from the water pump and the one on the back of the intake manifold as well, I didn't enable the heater yet but I have connected a hose between those two points to keep coolant flow through the manifold and cylinder head. Found that there was no thermostat installed, so installed one. Inspected water pump, a little bit of corrosion but the rotor and impeller was good, no play at the shaft. Refilled all the system with 50/50 mix and have to add some distilled water as I got short of coolant to top up the radiator. Fan clutch was replaced as well. I've been having random overheating, it is worst when A/C is turned on, obviously because the condenser is in front of the radiator. But sometimes runs good and the needle does not go above 210. I do not know where the needle it is supposed to be when the cooling system is working as it should. There are sometimes that random misfiring is happening, not too critical but I'm sure I'm not getting a perfect tuned engine. I've replaced the radiator cap just to discard this is the troublemaker. (13lb new one installed) Does the water to coolant swap have something to do with making debris and metal corrosion to become loose and start building a sediment inside the engine's block?