Cause or effect?

[belyle]

Moving on to the next problem on my '80 Brat: overheating. I am not convinced now that my overheating problem is caused by my coolant loss. I am thinking now that the coolant loss is more likely caused by running too hot.

 

I'm losing about 1/2 qt of coolant every 50 miles. I check it every day that I drive, and I drive about 50 miles to and from work.

 

The engine seems to run hot. At 50+mph, I don't have any problems, because I'm forcing a lot of air through. Temp gauge reads just above the lower tick mark. However, if I'm going slower than ~40mph (especially after going 60), the temp climbs, with the temp gauge reading somewhere above half, although below the upper tick mark.

 

When I'm running at lower speeds, especially in town, I have to use my heater as a 2nd radiator just to keep the car from overheating. If I get off the freeway, then go to town, the temp gauge will read right at the upper tick mark. Just a little warmer, and I'm blowing steam.

 

I've checked the radiator fan, and it seems to be working. It's spinning and moving air at least. Maybe not fast enough?

 

I've been topping off the system with coolant every day. Like I said, about 1/2 quart. I replaced the radiator cap, since my old one was crap, but no effect.

 

Here's what I'm going to try:

Flush + fill coolant

Replace thermostat with 180 degree

Add a reservoir so I can see if I'm losing coolant from the radiator vent

 

Anything else that I should look for? What else could cause this overheating? Running lean? Too much load on the engine at all times? ??

[john in KY]

30-year old radiator may be a contributing factor.

[lonnie]

chances are it is the radiator however if your rig has been neglected a good part of its life then it certainly could be a combination of things. if you plan on keeping the brat, then at some point you will have to do something about the entire cooling system. So too should you address the the engine tune, etc. as these things become older , the cheap quick fixes over the past many years catch up and it may now be the time to renew/restore the existing system.

[belyle]

30-year old radiator may be a contributing factor.

 

So... Rebuild radiator? Buy a new one? Thorough cleaning? I'm not sure what to do about an old radiator. Or, should I look at getting a newer/bigger one? Can you help point me in the right direction?

 

chances are it is the radiator however if your rig has been neglected a good part of its life then it certainly could be a combination of things. if you plan on keeping the brat, then at some point you will have to do something about the entire cooling system. So too should you address the the engine tune, etc. as these things become older , the cheap quick fixes over the past many years catch up and it may now be the time to renew/restore the existing system.

 

The car was tuned up pretty thoroughly (according to the receipts) a couple thousand miles ago. The guy that had it before me was using it as an around town car, but never put any long miles on it. Not sure the history of the car before him.

 

One of the receipt notes said that the mechanic recommended replacing carburetor, but nothing else caught my eye. I was planning on doing a whole tune-up (oil+air filters, oil change, plugs, wires, cap+rotor) in the near future.

[lonnie]

suggest your approach to fixes be guided by your long term interest in car. assuming you plan to keep it, i would find a good radiator shop and simply have it rebuilt. my experience is the certainty around fitment, sizing and assurance from the shop it will work, is worth more the older i get.

[hatchsub]

Go with your thought of using a overflow bottle and see if coolant is escaping that way. I had a similar problem two summers ago and thought i had popped a headgasket cause most of the coolant was gone. Then i realized that the cap might be to blame...not holding in enough pressure and letting the coolant out the overflow onto the ground. I put a new cap on and no more coolant loss which also meant no more heating up.

[belyle]

Today is the first day I've driven my car when the pavement has been dry. (No exaggeration; I live in Seattle area). When I got out from work, I noticed a sizable wet area under my car. Actually two, but one was oil (I think my oil pan gasket is bad, too).

 

Anyway, it looked like the origin of the coolant on the ground was from my water pump area. I am going to replace that, and the thermostat, and add a reservoir this weekend. I was going to replace the hoses, but I checked them today, and they look really good. I think that they must have been replaced in the last couple years.

[belyle]

I added a reservoir (see picture), replaced water pump, replaced thermostat, replaced upper hose, and refilled with coolant.

 

 

After re-doing the thermostat gasket (pinched the thermostat in with the gasket, leaking coolant all over my garage), everything seems to be not leaking.

 

When I was pulling the water pump, one of the bolts broke off in the block. I tried all afternoon Friday and all morning Saturday to remove it. I finally called it quits after trying everything I could think of (not an EZout), and everything my dad (who is a mechanic) suggested. I reassembled with only 4 bolts. I'm hoping that it will be enough. It was actually previously held on by only 4 bolts as well. Somewhere along the way, one bolt had fallen out.