1994 E420 Engine overheating

[pbalraj]

Car was not driven for nearly a year due to other engine issues. It is now running after replacing with three used units namely
1. Trottle body
2. e-gas module
3. Base module.
Motor running very satisfactorily. However, it is overheating. This morning after 2 minutes to the highway and 3 minutes on highway temperature gauge was already bordering the read zone. nearly 120 degrees. I am now parked in the office lot with the auxiliary fans on full blast. However, I couldn't hear the roar of the main fan and the gage is at 120. There id no hot air from the HVAC, just luke warm. Outside temperature is only 40 degrees Fahrenheit. Yesterday the outside temperature was 70 degrees and with the AC on the engine was overheating close to 120 degrees. I
let it cool down, then restarted it with the expansion tank cap off. Temperature climbed up real fast with gurgling sound and steamy hot coolant overflowing from tank. Shut it off and could hear a gurgling sound in cabin near vicinity of heater core. I am wondering if the fan clutch has failed. Had it replaced with new clutch about 25000 miles ago. Any suggestion as to how to get air out of the cooling system it that is the cause of my woes.

 

[pbalraj]

Update. Followed previously recommended procedure to remove air from system and problem solved. I filled coolant via upper rad hose and then fill expansion tank and run with max heat setting. Worked like a charm 87 degrees. Thank, got it from a previous post in 2015 from yours truly gerryvx. Thanks again.

 

[gsxr]

Good to hear it's fixed... but still no clues as to how the air pocket appeared in the first place? This usually only happens after draining & refilling, without filling through the upper radiator hose first.

 

[pbalraj]

Hope it did not develop a leak while it was parked for an extended period . Will monitor coolant lever closes for leaks. What I do remember is that a few days ago I filled the expansion tank because it was empty and dry and I fill it before I started the engine. Today before I filled via the top hose the expansion tank was empty. It took approximately 5 pints of coolant via top hose. Therefore there was quite a bit of air in the system. Will monitor closely and update accordingly.

 

[gsxr]

Yep, you have a leak. The tank should never be empty. When cold, normal level is filled to the seam on the tank, roughly 1/2" below the top. You'll need to figure out where the coolant is going.