Car overheats at idle. Cause?

[adam_knox]

So the Chrysler has a problem that when it is idling it will overheat. I thought it had something to with the Southern heat, but alas it wasn't hot out today. Had it idling in the driveway for about 5 minutes and came back to the car with the temp at 212! and heard water bubbling in the radiator. If I hit the accelerator whether in gear or in neutral the temp goes back to normal. I replaced the thermostat back in May and the radiator has been flushed a few times since I've owned it, always coming out pretty darn clean.

There's a squeak coming from somewhere, but even with a stethoscope I can't locate at. Does this sound like a water pump issue? I'm on a really tight time and money budget these days, so hoping to narrow down the most likely cause. Hope everyone is having a great weekend, thanks in advance for any tips!~Adam

[TodFitch]

Insufficient airflow through radiator: Is there a shroud missing between the fan and the radiator? Is the pump/fan belt loose?

Insufficient coolant flow through engine: Bad water pump or loose belt?

[Andydodge]

Adam, I'd recheck the thermostat, from what you said it sounds like its not opening and letting water flow thru the radiator......drain the radiator, check that the thermostat does actually open by placing in water in an old saucepan on the stove and bring the water to the boil.......maybe before you start to take the thermostat out recheck that the fan belts are o/k and tight.........otherwise it does sound like the water pump.................andyd

[thrashingcows]

Shrouds do make a huge difference. But did these cars ever come with one from the factory?

But definitely sounds like a water flow issue. Be it a bad water pump, or restrictive radiator, or malfunctioning thermostat.

[james49ply]

I have that problem with mine also, new water pump, belt tight, I will make a shroud and try that, or try a smaller pump pulley first. I think the flow rate is too slow at idle, and all I have to do to cool it is raise the rpms and it cools down.

[hkestes41]

I made a shroud for mine that has made a big difference. Not all that difficult just took some time letting the fiberglass set up. Here is how I did mine.

1) Cut a piece of thin plywood slighlty larger than the core, making sure to cut a notch to fit around the upper and lower hoses.

2) Cut another piece about 1 inch larger diameter than the fan.

3) Measure the distance from the core to what would cover about 2/3 of the fan blade.

4) Cut 4 blocks of wood as standoffs between the two pieces of plywood taking in consideration the thickness of the plywood to give you the total measurement from step 3.

5) Measure to get the proper position of the fan to the core both horizontally and vertically.

6) Using the plywood and standoffs screw or nail everything together using the measurements from step 5 to position the round plywood piece to the core plywood.

Here is what you will have after you get through with step #6

7) Get some fabric with some stretch to it and lay it on the round plywood piece, staple it in the center then staple around the perimiter of the round plywood. Once you have the fabric stapled to the round piece, stretch it down and around the back side of the core sized plywood and staple it all the way around. Now you have your form.

This is the form with a coat of resin painted on before I started adding the glass cloth.

8) Get some fiberglass cloth and resin. Mix a batch of resin and paint it over the fabric form then start laying your fiberglass over the form. Lay up as many layer as you want to build up to a thickness you are comfortable with.

9) Once all the fiberglass is set, drill a starter hole in the round plywood and use a jigsaw to cut around the edge of the plywood to remove it from the shroud. Do the same with the core sized piece of plywood.

This is after everything set and I have cut off the first half of the round plywood. It is turned upside down on top of the remaining shroud.

10) to make room for the lower hose, I then cut a notch in the shroud and used a plastic drinking cup cut on a diaginal and glassed it to the inside of the shroud to form a "pocket" for the hose to run in.

11) Sand, paint and attach with two pieces of aluminum angle screwed into the shround and core support. I also used some stick on rubber weatherstrip from Home Depot between the shroud and the radiator to seal it and prevent rattles.

Here is the shroud before I realized I had to make the pocket for the lower hose.

And here it is installed.

I cleaned up the edges around the fan opening and painted them so it looks better now than in the photo.

[thrashingcows]

That is how I'm going to make mine....came across this procedure a month or two ago and was blown away at how simple it is.

By the way...you did a very nice job on your shroud!!

[Don Coatney]

I made a shroud for mine that has made a big difference. Not all that difficult just took some time letting the fiberglass set up. Here is how I did mine.

Execelent "how to" article! Thanks for posting

[Charlie Olson]

Remove the radiator cap, before it gets too hot; wait until it is over heated, take a flashlight and see if the water is flowing in the radiator; if not thermostat is not opening.

[aero3113]

There is this shroud on ebay, but I don't see how it will work that well being flat.

http://cgi.ebay.com/ebaymotors/49-50-51-52-53-54-55-56-PLYMOUTH-CHRYSLER-DESOSTO-DODGE-/290528797859?pt=Vintage_Car_Truck_Parts_Accessories&hash=item43a4dda4a3

[thrashingcows]

There is this shroud on ebay, but I don't see how it will work that well being flat.

http://cgi.ebay.com/ebaymotors/49-50-51-52-53-54-55-56-PLYMOUTH-CHRYSLER-DESOSTO-DODGE-/290528797859?pt=Vintage_Car_Truck_Parts_Accessories&hash=item43a4dda4a3

I saw that one a month or two ago. It will not fit my Desoto, the opening is to centered and won't fit the position of my fan.

[Frank Elder]

In the ad it says we made this years ago......I guess nobody thought it worked then either.

[rustyzman]

Now that is one fantastic fabrication of a shroud. Really nice job on that. A lot more practical approach than panelbeating one out of metal.

[Dodgeb4ya]

Is the lower part of the block clear of cooling system sludge? Sounds like a restriction of coolant flow- could be caused by radiator/block or thermostat problem. This 1950 Windsor engine was over heating because of a clogged radiator and block.

[adam_knox]

Well thanks gang! Ended up replacing the water pump (that was the squeeky culprit) and the thermostat. Flushed out the system, though no crud came out, just some rust tinted fluid. Didn't pup out the welch plugs either as time was limited. Of course I have a leak dripping somewhere, but it'll have to wait. I calculated it to be a quart every 21 hours, so I'll just have to bring a water bottle for me and a water bottle for the car every day until I can try a new gasket.

[Al B. Bach]

Very cool write up! I was a composite tech before I got laid off so this would be an easy project for me. I just never really thought about it even though my car runs pretty warm as well. This is now certainly on the to-do list.

[Drdialtone]

Aero, I bought one of these wondering if it would be a an addition to increase cooling efficiency. Haven't put it on yet... but being flat means it won't work? Curious as to why... if the fan is pulling air in from the center of the radiator, it seems that it would concentrate the air to pull more from the front of the radiator. No?

[aero3113]

I think it will work well with the fan but what about the forced air while driving? I think it would block some of the air and not allow it to flow in and cool the engine. Just my thinking but may work fine.

Edited April 19, 2011 by aero3113