Guest Posted August 1, 2002 Share Posted August 1, 2002 I own a '67 Olds 442 with a stock 400 cubic inch engine and a four speed. The engine has been rebuilt and has a tendency to run hot at idle (especially on warm days - up to 230 degrees water temperature). When the car is moving, the water temperature is fine (normally between 165 and 180 degrees). I have done the following to try and remedy the cooling problem:<P>* Installed four core radiator<BR>* Maintain 50/50 coolant & water<BR>* New thermostat<BR>* Installed Flow Cooler water pump<BR>* Installed Four Seasons electric "pusher" cooling fan (manual switch operation)<BR>* Installed high performance aluminum fan to replace original four blade fan<BR>* Checked out: Mufflers, timing, carburetor (richness & idle), spark plugs, fan shroud, expansion tank, freeze plugs, hoses -- all O.K.<P>The only things I can think of that can be contributing to the cooling problem are internal: Core shift (thin block walls between pistons due to overbore) or blocked water passage due to improperly installed gasket. Another issue is the electric cooling fan - it doesn't seem to push much air through the radiator (the fan is installed correctly). I tried contacting Four Seasons technical support, but was less than impressed with their customer service. Even if the cooling problem is internal, wouldn't a good electric fan compensate for the problem? (A cooling fan should have the same effect as when air passes through the radiator of a car in motion).<P>Any suggestions are greatly appreciated -- I'm getting ready to attend a car show in September, and this cooling problem is extremely frustrating.<P>Thanks,<P>-Martin Link to comment Share on other sites More sharing options...
Guest Posted August 1, 2002 Share Posted August 1, 2002 I saw a program on the tube once that blamed hot running Olds motors on a bad cylinder head design.Todays software would eliminate that,I suppose.That being said,I can only make a couple of suggestions since youve covered just about everything.Make sure the rad cap is new and no junk.Have the system pressure tested to eliminate a possible blown head gasket.Good luck Link to comment Share on other sites More sharing options...
Guest Posted August 2, 2002 Share Posted August 2, 2002 Thanks for the advice - much appreciated. The radiator cap is a stock replacement and the system pressure checks out as O.K. (I've always had a suspicion there's a design flaw responsible for the problem - your comment helps confirm it).<P>-Martin Link to comment Share on other sites More sharing options...
66400 Posted August 2, 2002 Share Posted August 2, 2002 Design flaw???? I live in Texas and I've a number of Oldsmobiles '66 442, 400 4spd 3 row radiator with factory air cond, '66 f-85, 330 automatic 3 row radiator with factory air cond, '69 442 400 automatic 4 row radiator with factory air cond, all these cars do well in the summer heat. My '65 442 400 automatic 4 row radiator with factory air will overheat but I'd blame the earlier style down flow radiator for that. Henry Link to comment Share on other sites More sharing options...
Guest Posted August 3, 2002 Share Posted August 3, 2002 SJ, My question is " is the coolant actually that hot or are you going by the temp gauge. Have you actually stuck a thermometer in the coolant? I knew a guy that had a GTO with the same problem and he cured it by reducing the anti-freeze content to water. Something about the ability of the water to dissapate heat faster then anti-freeze. Hope this helps. Ron Link to comment Share on other sites More sharing options...
Guest Posted August 3, 2002 Share Posted August 3, 2002 Henry & Ron,<P>Thanks for the additional feedback. It seems I get a 50/50 split from folks on whether or not the cooling problem is the result of an unspecified design flaw. Since I've eliminated pretty much all of the "external" sources of cooling problems, I'm inclined to think the problem is internal (aside from a design flaw, it could also be the result of the engine rebuild - for example, core shift or a faulty gasket).<P>The issue of coolant to water ratio is also something I'm investigating - some experts say to use a 1 to 5 ratio of water to coolant because water is superior at dissipating heat (exception: Hot climates).<P>To make things even more interesting, I received info from tech support at Summit Racing:<P>"The problem with a four core is this, you have 4 rows of 3/8 tubing. That translates to about 1 1/2" of surface area. Now here is the problem. It has been found that when the air hits the third row, it begins to tumble. This results in no heat being transferred from the fourth row, and only partially from the third row.<P>So, we're now down to around 1" of surface area. At highway speed, you're moving enough air through the grill to keep it cool, but at idle, problems can occur. Now add a pusher fan. Running as a pusher, you lose 15-20% of the fans cfm rating. Now you've lost that amount, plus about 33% of the radiators surface area. The solution: An aluminum radiator with TWO rows of one inch tubing. You have doubled the surface area, plus have the added heat transfer of the aluminum over copper and brass".<P>My next step will probably be to replace the pusher fan with a puller fan, and see if that does a better job of moving air through the radiator at idle. If all else fails, I'll take a closer look at the aluminum radiator.<P>-Martin Link to comment Share on other sites More sharing options...
Guest Posted August 14, 2002 Share Posted August 14, 2002 Make sure the thermostat is installed correctly. You could have problems if it is backwards. I don't mean upside down, I mean front and back. Usually one side has a bleed hole. There should be a marking on the thermostat body indicating which side should go towards the radiator. Try a RobertShaw brand. Good luck! Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2002 Share Posted August 18, 2002 Thanks for the advice concerning placement of the thermostat -- since I'll be draining the radiator this weekend and filling it with a higher water to coolant ratio (from the current 50/50 ratio to 20% coolant, 80% water, and Redline WaterWetter), I'll double-check the thermostat.<P>Regards,<P>-Martin Link to comment Share on other sites More sharing options...
Guest Posted August 20, 2002 Share Posted August 20, 2002 Since freezing is not a concern during the summer, replace 50/50 with water plus a rust inhibitor/water pump lubricant. That's not a cure, but it'll help as ethylene glycol has a lower specific heat than water. As a longer term solution, I suspect there's something inhibiting coolant flow, but that'll take at least a partial engine teardown to determine.<P>P.S. I bought a '67 with a 400 and 4-speed new and never had a cooling problem. Link to comment Share on other sites More sharing options...
Guest Posted August 22, 2002 Share Posted August 22, 2002 Thanks for the advice concerning the water to coolant ratio (I'll be changing it over the weekend). It's also my fear there's some internal cooling system restriction problem. If you haven't had a problem with your '67 442, then that's another data point against the problem being a design flaw (at one time I had considered that as well because I knew a few other '67 442 owners with similar cooling problems).<P>Thanks again & happy Oldsmobiling...<P>-Martin Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now