Packard Forum Index » Pre-War (1899-1942)

I realize some of this topic has been discussed previously, but would like to post this and make sure I have covered all of the possible solutions.

Background: I started the restoration 18 years ago. Block was cooked and flushed, all new bearings, pistons, etc. were installed. Radiator was cooked, flushed and pressure checked. It was not re-cored at that time. Engine was run twice for about 3 hours each time over several years until last November, then run again with no problems. Note: radiator had 50/50 antifreeze/water mix in it for years while being stored.

Car finally assembled this spring and summer. Engine was running with no problems, but had a carburetor issue. Carb repaired and run again..... within 15-20 minutes it overheated while driving it back and forth in the driveway.
Continues to overheat.

What I have done: water pump removed and inspected, radiator and block drained. Radiator flushed using water from garden hose and captured. Only very tiny rust particles present and not very much of those. Pretty clean. New 50/50 antifreeze installed (note: Packard specs state 18 quarts in system - I could only get 14-1/2 quarts in it). Heater valve (on top of head) and block drain plug opened to remove air pockets. Air came out of heater valve, but just steady stream of coolant out of drain plug. Heat riser valve in exhaust manifold tested - works properly. Using a laser temperature device when running the car at idle, radiator temperature differential between top and bottom is approximately 40 to 50 degrees (cooler at the bottom of course).

Temperature gauge needle gets to 212 degrees, but laser devise shows a little less at probe entry point. Gauge was not rebuilt because it worked when I tested it. After shutting engine down, in a few (15-30) seconds or so it "burps" coolant from the overflow tube. There are no detectable leaks in the radiator or anywhere else. Not a head gasket issue - oil looked good, but was changed again along with coolant. Has anyone rebuilt their engine, then had this issue due to close tolerances of new parts (bearings, rings, etc.) which builds up heat in the block? I don't believe the rings have seated yet because this motor has not been run "under load" - by driving it. Any advice would be greatly appreciated. I have waited a long time to get this thing done, now I am stymied with the overheating. Daryl

Forgot one thing: does anyone know what the "normal" operating temperature is (say at 70 degrees ambient)?

A couple of pictures.

Attach file:

---

  (375.00 KB)


  (387.80 KB)


  (302.40 KB)

Normal operating temperature is a few degree either side of t he thermostat rating.

Thanks! Has 155 degree thermostat. I tested the thermostat in a pan of water yesterday - works just fine. Temperature at the probe using laser was 200 to 205. Similar at the gooseneck.

Incorrect timing can cause overheating, check with timing light and check advance.

Another poster had a similar problem, checked everything and found all in order. Checking again he found the water pump gasket which he had made was missing a critical hole

Timing was checked with timing light. Timing is right on the money. Water pump gaskets were NOS made by Victor. I did notice this small oddball hole.

Funny thing is the car was running fine..... idling at 180 degrees with no problems, except a small carburetor problem. Shut it down, had carb corrected, and started the car up a couple of days later....... and it overheated. I keep asking myself "what changed"??

If you are getting rust particles out of the flushes you probably have the upper radiator tubes clogged. Try aiming your laser temp device at the middlle of the radiator downtubes. If it is much cooler than the top, you probably have blocked upper tubes from the block. I would suggest that you reverse flush the radiator first then the block using a car ( not a diesel) exhaust. I believe that the procedure is listed somewhere on info.com. but I am a different computer from my normal one and cannot use this computer properly. I have also modified the blow-out procedure for a more efficient blow-out of the block. I hope to detail this within say 24 hours. best regards and it does work well without removal of the radiator and at negligible risk to the radiator tubes. There are a few U tube videos of this at one of the Australian Rallies (Mittagong?). Peter Toet

A clue that "something changed" when shut off for a short period of time. The water pump impeller could be loose, would give these symptoms.

The temp drop down the radiator seems to show it is wide open, the low temp at the bottom outlet seems to show that all is OK there

There has to be an easy answer

I keep hoping for something simple that I have missed. Water pump was inspected closely with no issues (impeller not loose, no wobble, etc.). At this point, I do not want to remove the radiator..... unless I am absolutely sure that it is the problem ...... anyone who owns one of these cars knows exactly what that entails..... not good. Pretty much the whole front clip has to come off. It appears we will be getting some cooler weather in the next few days. I will go early in the morning and see what happens with ambient temps in the high 60's instead of the mid 80's.

Temperatures in the 80's/90's existed in 1936 and the cars ran fine. If the temps are 20 degrees lower that will not fix the problem

Perhaps i missed it but I didn't see mention that the radiator flow rate was tested. If everything else is up to snuff the radiator rises to the top is the suspect list. It can be removed without removing the entire front clip.