Engine always runs HOT

[Guest]

My '51 Roadmaster likes to run hot. Whether I'm driving in the summer or the winter, it WILL overheat if I sit in traffic any longer than 5 minutes or so (a real pain during stop-and-go parades).<BR>The fellow I bought it from told me it likes to run hot, and has for years.<BR>I've checked the radiator (new core) - which seems to be doing it's job properly. I've also made sure that the manifold heat riser is unstuck and now functioning, but with no real change.<BR>The car runs pretty nice otherwise, although as it gets hot the engine's performance definately begins to suffer, and it's a bear to restart.<BR>I'm looking for help and/or suggestions. Do many others on this board have similar temperature problems with their straight 8's from the same era? Is this characteristic of these cars.<BR>Any help would be appreciated. Thanks in advance.<BR>-Rich

[Guest]

Check to see if the waterpump impeller is circulating the coolant properly (open the radiator cap and see if the water is moving rapidly). I'm sure you have checked or replaced your thermostat? Also, check the waterpump bypass hose (if there is one--can't recall on the 320 straight 8). It could be kinked or blocked at either end, especially if the engine sat a long time with no hose on it--mud daubers or mouse nests.<P>It has been my experience with Buick straight 8s that almost all of them get pretty hot if they have to sit and idle for more than five minutes.

[billbuickgs]

Rich, Its been many years since I owned a str. 8 but they do get sludge built up in the block and head after many years of operation. Use a strong engine flush and follow directions. Remove the side drain plug and try running a stiff wire to insure there is no build up. When I did a valve job, I was able to use a wire in the head along the intake side and also vertical in the block around the rear cylenders. Good luck, its getting hot out there!! Bill

[Guest]

Dear Pete & Bill;<BR>Thanks for the advice. I neglected to mention before that I have changed the thermostat before. The water pump is relatively new, but I suppose it could be bad or it's impeller blades might be too small. I'm not sure it has a bypass hose - will check that out!<BR>I think my next step will be to have the engine flushed.<BR>Was most interested in Pete's admission that these engines tend to run hot, especially during long term idling.<BR>Does any other straight eight folks out there want to comment on whether or not their engines inheritantly run hot? And if they would recommend any fixes for this problem. -Has anyone ever found & tried a shroud?<BR>Thanks,<BR>Rich

[Guest scott mich bca # 6619]

Rich,<BR>I had the same problem with my 322 V8.<BR>I reverse flushed the radiator and the block by cutting in one of those tee's in the heater hose.<P>I first flushed the heck out of it just with water and the garden hose. Next I ran the radiator flush solution in the system for a few days.<P>Next ran the garden hose clear water flush<BR>again, till it was completely clean.<P>Filled it with fresh antifreeze, the proper mixture. It ran a lot cooler. It was also recommended to me to remove the freeze plugs and fish around with a wire brush and coat hangar, as the passages around the cylinders build up sluge over the years.<P>You may want to do the flushing yourself, or take it to a garage with modern flushing equip. However I do not know with the modern<BR>equip. & the EPA if they would flush it as much as you could and agressively as you can.<P>But I would try the flush first. If your block is pluged, even with a fan shroud, or a thicker radiator, you will still have problems.<P>If your timing is off or your compression is low, it could also cause overheating.<P>Good Luck, let us know what solves your situation.<P>Scott Mich<BR>1955-76C<BR>Assistant Director<BR>Chicagoland Chapter

[Bill Stoneberg]

Rich,<BR>I have a 47 Super with the Str 8 that has similar problems. I went through the engine and boiled the block, changed thermostats, ran straight water with no anti freeze, played with the timing etc. etc. etc. I finally got tired of it and put on an aux fan with a thermostat that turns it on and off. No problems now. I can even use the A/C too.<BR>Obviously my car is not stock but I tend to agree with Pete. They do run warm as a rule.<BR>Bill

[BuickNut]

I have a '49 Buick Super 4 door with a 248 str 8...been years thats its been in storage, but I used to drive it quite regularly...with the same overheating probelm you had. I had since put in a new rebuilt radiator and flushed the system, though not as agressivley as described. Don't know the end results though, as I then put it into storage at that point.

[Guest]

Bill:<BR>Was the auxilary fan electric? Did you remove the original engine fan, or did you mount it on the front of the radiator and run them tandem? Is it 6 volt? Do you remember where you got it/cost?<BR>Thanks,<BR>-Rich

[Guest]

I had a '39 Model 90 that I restored with the 320 ci straight eight. When it was freshly restored, it ran very hot, you really couldn't drive it much if the ambient temperature was above 80 F. But, it got better with time, I think the high friction in the rebuilt engine contributed to the problem.<P>I did find reverse flushing to be very helpful. The passages between the block and head are very small on these engines -- and they tend to fill up with rust flakes. Reverse flushing at least pushes them out of the way, and it takes a while for them to come back.<P>I drove that car across the country twice in the summer, and though I always had an eye on the guage and avoided traffic jams, it did make it without any severe boilovers (the '39 is not pressurized, and mine was not modified to have pressure). I think high temps are a characteristic of the engine, so you might get used to it. I remember driving with my family to California in 1951 in a brand new Buick Special -- my Dad fumed constantaly about his overheating Buick!<P>Good luck.

[Guest]

Bill:<BR>Thanks for the imput, although it really WASN'T what I wanted to hear. I'm having trouble believing that these beautifully engineered cars with their powerful engines could all be overheating!<BR>I, too, drove my 72R across the country, last summer. I drove through the heat (well over 100F) and through the Western U.S. wildfires. Although my Roadmaster ran very hot, my Son & I watched the temp gauge religiously, and pulled her off the road into the shade many times to allow the engine to cool off. I, too, was fuming about my Buick overheating.<P>-Anybody else out there in BCA forum land that would care to report otherwise about their 'straight 8' Buicks experiencing hereditary meltdown?<BR>-Say it ain't so, Joe!<P>Thanks in advance,<BR>Rich

[Bill Stoneberg]

Rich,<BR>I have converted to 12 volts to handle the A/C I put in. I got the fan from Speedway in Lincoln Nebraska though any Rod shop will have them. It was about a 100 bucks.<BR>I mounted it in front and it pushes air through the radiator. I still have the original fan on too.<BR>I am looking to see what my 50 Super will do, I just have finished putting the engine together and I have a feeling I will need a fan too. Down here it gets hot and humid and the old cars have a problem keeping cool.<BR>Good luck<BR>Bill

[old-tank]

Is it actually hot or does the guage just read high? If it is belching coolant all over the road it is HOT. On my 55 322 the guage was showing hot with a new clean motor and new cooling system so I put a mechanical guage on the other head and at 200 deg the stock guage was high enough to make me nervous and at 220 deg the stock guage was pegged and definitely giving me white knuckles! With pressure and antifreeze you can go higher than 212 deg before boiling over. Most new cars have 195 deg thermostats.<BR>Just some observations...Willie

[Gene Brink]

My experiences are from years ago ('50 & '52 Supers) and both ran without any overheating. Bought the '50 used (my first car) in '63 and drove it for several months until I inherited the old family car (a '54 Super). The '52 was the families main car (picked up at the Flint factory in August '52 - saved the shipping charges that way, then at least) until the summer of '62 when dad got his dream - a Caddy (owning a Cadillac was the dream not necessarily the car [a '59 which was a great car]) after which the '52 was relegated to "back and forth to work." Prior to that it made a trip from California to Ohio every other year, on camping trips all over California, etc. and the only time it ever overheated was on the Ohio turnpike. We sat by the roadside until it cooled down, filled the radiator with some not too clean water from a little creek by the roadside and went on our way. Never even bothered to change the water - just added a jar of water pump lubricant to it.<P>Drove the car to the junkyard (with almost 167,000 miles on it) in 1966 right after my parents returned to Buick with a new LeSabre. Received the princely sum of $15 for the car if I remember correctly.<P>Given the number of people advising that their experience with straight eights has been that they run hot we may have been lucky. My dad is just certain that having run straight 10 weight oil in all of it's life was the reason it did so well. I doubt it and figure the regular oil changes were the key to long life.<P>The only persistent problem I can remember is the push rods plugging up resulting in rocker noise. We got pretty good at popping the valve cover off, pulling rods and cleaning them out with a coat hanger wire every couple of years or so. Don't think that would happen with new oils today but back then it sure did.<P>Hope you solve your problem, Rich. Seems most likely that a good flushing will help the most.<P>Gene