replaced thermostat, hoses, flushed system, rewired fan(toggle switch), added a second fan(toggle switch). There is no leaks in the radiator and the cap is fine. temp guage goes to halfway mark and higher when the car gets up to 55mph. this is with both fans running? I haven't taken it out on the highway for fear it will completely overheat. before I swap out the radiator is it normal for the temp guage to run between halfway mark and the3/4 mark. I'm used to ea82's that run all day at the 1/4 mark. any feedback appreciated. Just took it out for a ride tonight, its 20 degrees outside and it still runs hot:-\

 

ps running the heater makes no differance on the temp guage, the heater core is fine.

all signs point to REPLACE the WATER PUMP!!!!!

 

'78 BRAT runs at one nedle width BELOW the first line, there are 2 in a narrow gap of mid-range, NEVER above 1/2!!

 

whether it idles along @ 1500 for 4 hours continuous or drives @ 3600 doing 58mph for 3 hours continuous, it never budges above!!

 

engine driven fan does a great job of cooling engine

electric fan works great

My temp guage in the 77 sedan has 2 marks, one smack dab in the middle at12:00 and one at 3/4. I assume these 2 only marks represent the mid range.

On start up it steadily climbs up to the first mark. once I take it down the road it will climb halfway past the first mark, then drop back down to the first mark again. I imagine when it drops back this is when the thermostat opens up. I did a 100 mile trip the other day and it pretty much stayed at 12:00 (the first mark).

I suppose I should forget about all this guess-work and install a temp guage that will give me a more accurate read. I did pick up a brand new water pump, but perhaps this is the way its meant to run. It just looks strange to see the temp needle in the middle like that.

There's at least one more possibility, advanced ignition timing can cause overheating. This is usually accompanied by some detonation at higher rpms too. I've been through this on my EA71.

 

And then there is one more that I can think of that I'm sure you have already checked. But if your engine is significantly low on oil, that will cause your engine to run hotter than it should too.

 

After warming up, my brat sticks right on the middle mark unless I'm asking more of her.

 

Best,

Crabman

weeping head gasket?

 

I had a 78 brat that got really hot at idle and at freeway speed but somewhat normal while backroad driving. Couldn't figure out why till the head gasket finally gave up and it was just downhill from there (literally, haha)

 

Good luck,

-Mike