Question About Overheating Engine

[Darkness]

Okay, so I got a question for everyone. I was digging through some threads says that reading that a bad water pump has a lot of play in it. Anyways, before I go check it out I was wondering if my water pump would be working correctly. Okay my overheating issue is around town and idling. Once I get on the highway it cools down to where it should be. Does this sound like a water pump issue or thermostat? Thanks.

[Blown70]

Dark,

Sounds like air flow, Check the cap, the thermostat, and the pump.  Honestly i have seen it be several.  You running a shroud?

Tom

[Darkness]

Thanks Blown. No I don't run a shroud on it. I got a thermostat for it but, before I got put that on I want to make sure that's what it is before I go putting everything back together. The cap looks good. It's a Stant and when I drained the antifreeze today I didn't see any rust or brown in the antifreeze. It was clean. Now one thing I noticed is that the guy who reinstalled the engine overtighten upper radiator hose.
I found this out today because when I loosened up the radiator hose the drain off the antifreeze went from a small stream to a gush into the pain I put underneath. I figure that might be it but, not sure and if I have to replace the water pump then I might as well wait anyways since I'll have to pull the motor and I want to install a smaller cam.

[dodge freak]

You need a shroud!! If you don't want one well maybe you can put a electric fan in front or try to move the fan closer to the rad. But really a shroud is what you need at slow speed. I have gotten away without one but in was in a big old grand fury 77 and it had only a 318 and a duel exhaust with no cats. and a 160 thermostat. I  am -should say was- a very good driver and was able to keep my speed almost always over 25 and stop at very few lights. In my 40's now and can't  drive like I did in my early 20's . Hey I least I am honest with myself.

[Darkness]

Thanks dodge freak. I guess I could look for one but, I have a huge fan. It's a seven blade with 20" blades on it. I believe it came off of a C-Body because the part number tells me 74-78 Chrysler Product. But, anyways I'll see what I can dig up on E-Gouge for a shroud I guess. BTW, I don't drive very hard either.

[resq302]

On my 69 Charger, I had an overheating issue that was caused by a leaking clamp on the upper rad hose at the thermostat.  If you have a coolant leak somewhere, it will not allow the system to operate as designed.  A closed system will keep the temp down as it does not allow it to boil.  When you get up to the 212 temp range, your coolant which has water in it will want to start to boil.  Allowing the pressure to escape, like in my case, only let more air into the system causing the system to be able to boil, thus overheat.  Check for leaks in your system, do you have a bad head gasket? Oil getting into coolant or vice versa?  Do you have a lot of condensation coming out of your exhaust?  My leak was very small to the point I could not see it until it got worse.  After I realized I had a leak and fixed it, the problem went away almost instantaineously.  Also, Royal Purple makes a product called Purple Ice which reduces your coolant temps.  Good product as it worked to reduce my el camino's temp by 20 degrees.

[Blown70]

Shroud.  I had the same problem.  Air goes every where.  The shroud will help pull it into the radiatior.  Make a HUGE difference.

Tom

[NHCharger]

How far away is the fan from the radiator? If it sits to far back it won't draw the air through the radiator when sitting. Which is the purpose of the shroud.

[Darkness]

I don't have a leak as far as I can tell. The fan sits about 1" maybe an 1 1/2" from the radiator. I'll try to get a shroud and see if that works. Also, bought some colder plugs for it as well. Might help.

[Mfr426]

I learned the hard way about 10 years ago that a rap cap can cause an overheating issue. Mine looked fine and I was hesitant to replace it when an old timer suggested doing it. Instead I spent all sorts of time and money on other fixes. Well, I finally had nothing else to replace and put on a new cap (my old one "looked" fine). Well, needless to say it was the cap.

The rational was something about it not being able to build up pressure to work as it was intended causing the overheating. Not sure if I got that part right but the cap fixed the issue.

Lesson learned.

Mike R