Another OVERHEATING question

[dave1shere]

Hello All,

I have owned my 1985 MB W123 since last October. The temperature gauge has stayed at the 80c or less all winter long. Just this week our temperatures here in Central Florida have climbed into the 80'sF. Noramlly the needle rides in the middle of the 80c degree mark, but while using the AC, I have noticed that the needle climbs over the top of the number 8, in stop and go traffic it sometimes climbs almost to the next white mark. I read on a previous thread that some people have said that is where their needle normally reads. I have checked the electric auxillary fan, it appears to be working but is intermittent.

My question is, is this something to be concerned about? Could I, as mentioned once before on this board, rig the auxillary fan to come on whenever the air is running and if so how would one do that such as finding the fan relay and hooking it to the compressor power or is this considered a NO NO?

PS - have checked the main engine fan which is a 9 blade plastic fan. I feel some resistance when I try to move it so I assume the fan clutch is in good working order.

I have been reading this board for a while and appreciate all the knowledge that is shared here....thanks in advance for your help.

Dave

[ck42]

Dave,

If by the next white mark, you are saying it has reached 100C (white mark at 80C and another at an unlabled 100C) then that is a little higher than expected for stop n go with the AC on.....ALTHOUGH, it's NOT so hot that you need to worry about engine damage.

But....100C in stop n go on 80F days, IMHO, cerainly warrants having the
cooling system inspected. Could be something as simple as needing a new thermostat.