runnin hot m923a1

[absolutemoon]

Afternoon SS elites, So I flushed out the old antifreeze yesterday and got a full 5 gallon bucket worth of nasty old fluid. Went ahead and installed a new block heater for the winter. (started right up at 21* this morn) Now she is running hot about 15 mins into the drive. (approx. 220-240) I put 5 gallons of 50/50 back in her. I'm pretty sure she is a 40qt system. From what I see or hear, the fan is not coming on at 190* like it should. Where do I even begin to start looking for issues? Any help is appreciated. Thanks

 

[swbradley1]

Did you use automotive antifreeze or diesel? As in the kind with the supplemental cooling agent.

 

[absolutemoon]

Automotive. Prestone. Is there something else I should be using?

 

[MtnSnow]

With you saying the fluid that came out was nasty I would say check your Thermostat for being stuck/clogged closed AND since you stated you are not hearing your fan kick on you need to check your shutterstat

 

[74M35A2]

Start with diagnostics. There may be air in the system, check the coolant level again. If still running hot, feel the top radiator hose when gauge reads over 200F to see if it is hot or cold. If cold, your stat is likely stuck closed. If hot, then your fan switch is likely not working, check/test it. Check and compare temp of lower radiator hose. Radiator passages could be blocked. If all seems OK, it is rare but possible the water pump impeller is shot (dissolved).

 

[swbradley1]

You must use diesel antifreeze with the supplemental cooling agent in it. You have "wet" cylinder sleeves in the block and it eventually pit the sleeves to the point where you have a problem.

 

[rhurey]

5 gallons?

I got about 8 out IIRC, and put about that back in.

 

[absolutemoon]

I am literally laughing out loud at myself. Boy, I feel old now. 40qts is 10 gallons. DUH!!!!!! I will add more than the 5ish that came out and go from there. Thanks guys for waking my brain up.

 

[Carlo]

I've been with the site since 2012 and I think overheating is the number one problem with A1's and a2's. I thought my cooling systems were in good nick and one day I had a hole in my A1 and removed the radiator for repair. The fluid at the cap always looked new but at the bottom of the radiator there was sludge! Mud! The antifreeze looked so good but all this crud at the bottom of the radiator. The thermostat was also sticking. I repaired the radiator, did a power flush to the block and now the temp is perfect. I can't get the temp into the fan turn on range. So I did power flush to all my other trucks and got the same results.

 

[randygk]

Our M923A1 ran right at 180 degrees but the fan never came on. Replaced the fan clutch actuator and now the fan comes on. I had to run it uphill quite a few miles at about 95 degrees out to get the fan to come on. Yes, check for stuck thermostat or clogged radiator.