65 High Water Temperature Questions

[fatbuick]

I installed a water temp gauge and now that I have tracked the temparatures I was wondering if anyone can throw some light my way.

The engine is 425 GS LX Code and I have the original fan shroud, 5 bladed fan with clutch, 190 deg thermostat (not replaced yet) new water pump for AC. Weather is not hot, maybe 80deg.

At idle and around 35mph it stays around 190deg no problem which seems normal. When I increase speed and sit at 45-55mph the temp goes up to 210-220deg. Reduce the speed and temp comes down again.

My Questions are:

Do these symptoms indicate, poor water flow, blocked radiator, bad thermostat or what? At high speeds I don't suspect the fan makes much difference because air flow should be good, right?

I'm thinking maybe the thermostat is not opening fully and restricting water flow?

Thanks in advance.

[Dales90]

Hi,

I would change the thermostat, as it does not seem to be opening. Then you will have that item eliminated from the problem.

If it still exists, the fan clutch would be my next culprit.

good luck!!

Dale

[Guest slacker1965]

I installed a water temp gauge and now that I have tracked the temparatures I was wondering if anyone can throw some light my way.

The engine is 425 GS LX Code and I have the original fan shroud, 5 bladed fan with clutch, 190 deg thermostat (not replaced yet) new water pump for AC. Weather is not hot, maybe 80deg.

At idle and around 35mph it stays around 190deg no problem which seems normal. When I increase speed and sit at 45-55mph the temp goes up to 210-220deg. Reduce the speed and temp comes down again.

My Questions are:

Do these symptoms indicate, poor water flow, blocked radiator, bad thermostat or what? At high speeds I don't suspect the fan makes much difference because air flow should be good, right?

I'm thinking maybe the thermostat is not opening fully and restricting water flow?

Thanks in advance.

yep you are on the right track....the thermo is the quickest & cheapest thing to try....have you looked in the rad? running an engine hot is really really hard on it & potentially catastrophic, so get it fixed sooner rather than l8r......good luck & let us know

ks

[Lapham3]

Hi Tony-Thermo possibly isn't opening fully, but after ruling that out, I'd focus on a radiator rebuild-good luck-Dan

[fatbuick]

I agree so have replaced the thermostat this afternoon with a new one. (correction, it was 180deg and so is the new one)

Test drove it and it hasn't made any difference.

I don't see how it can be the fan clutch because it can sit idling for ages and it stays on about 190deg max. plus it would be getting heaps of air at 50mph even without a fan.

Again it's not a difficult change to make so I'll swap the fan from my 66 Wildcat which runs a constant 190deg in all conditions and eliminate one more thing.

[JZRIV]

Tony,

Is the water pump a 5 blade instead of 3?

Is your radiator in top condition. Was it a recore?

Was the block bored? If so how much over?

Just to rule it out do you know what your total timing is at cruising speed. I assume you have verified the mechanical and vacuum advance operation? Not enough advance at cruising speeds will create more heat which over taxes the cooling system.

I tend think overheating at cruising speeds is more related to coolant flow instead of air flow. While it (fan) does have some impact on cooling at higher speeds, since you have zero problem at idle with overheating I agree the fan is not a likely candidate.

PS send some of that 80 degree weather over here. It was 8 degrees this morning!

Edited January 3, 2013 by JZRIV (see edit history)

[60FlatTop]

Make sure you have a spring in the lower radiator hose and that the hose it not too soft. They can collapse slightly on higher pump flows.

Bernie

[RivNut]

Tony,

If remember correctly, you have a "trap" of some kind on your upper radiator hose. Is it preventing the flow of water at speed? Perhaps enough water will trickle through at idle but not at higher rpms (faster water travel.) You might try a hose without the trap and see what happens. How does the a/c condenser line up with the radiator? Good air flow through both?

Ed

[superbuick]

You have described a partially plugged radiator. Symptoms will be - normal temp at low speeds, then climbs at high speeds or a hill. Then will go down at lower speeds or slowing down. The radiator is simply a heat exchanger. When is gets plugged this is what happens. A good way to test is warm the car up, run engine at higher RPM for a short while them with a hand held temp gun shoot the radiator on each row. It should be even temp, but you will find a big drop in the spots were it is plugged. Thermostat is a good idea, but most likely will need a radiator rod out.

Steve

[fatbuick]

Hi Jason,

Thanks for your reply.

It's a 5 bladed pump, total timing is about 30-35deg. I don't know the history of the radiator or the engine block.

Both mechanical and vacuum advance are working. Will double check with timing light.

I tried lighter springs on the mechanic advance but it started pinging so reverted.

I'll get the radiator checked out when the workshops are back from holidays.

Not so much in Sydney but generally in other states we're in the middle of a heat wave. 111deg F in Adelaide for example and for about a week. They would like 8 degrees I suppose.

[Guest Rob J]

Sounds to me like the radiator needs a recore. Seems most folks are recoring to a 4 core, instead of the factory 3. I would most definitely get the radiator re-worked.

Rob.

BTW, it was 80 degrees today here in Miami. :cool:

Edited January 4, 2013 by Rob J (see edit history)

[Guest slacker1965]

Sounds to me like the radiator needs a recore. Seems most folks are recoring to a 4 core, instead of the factory 3. I would most definitely get the radiator re-worked.

I would tend to agree on the rad diagnosis....have you tried to flush the cooling system or drain the block? you would be surprised what you can sometimes accomplish with a garden hose & some rad flush.....just don't use too much pressure, these things operate at very low pressures <20 psi compared to homes 80ish psi (here in the states anyways)..... does the car have a good fan shroud on it? that won't cause your problem, but will help it run cooler on those 110+ days

[JZRIV]

Hi Jason,

Thanks for your reply.

It's a 5 bladed pump, total timing is about 30-35deg. I don't know the history of the radiator or the engine block.

Both mechanical and vacuum advance are working. Will double check with timing light.

I tried lighter springs on the mechanic advance but it started pinging so reverted.

I'll get the radiator checked out when the workshops are back from holidays.

Not so much in Sydney but generally in other states we're in the middle of a heat wave. 111deg F in Adelaide for example and for about a week. They would like 8 degrees I suppose.

It does sound like the rad is the next logical step in the process to find the root cause. I say that with some hesitation because sometimes these overheating problems can be tough to diagnose especially on an internet forum. What seems obvious, isn't always so. I recall some good conversation on overheating while back on the V8Buick nailhead forum. If you have time you may be able to search that forum and see if you can find it. Ahhh heck Tony, I'll save you the trouble. Here it is. There is probably more. Runnin hotter than normal,need suggestions

Edited January 4, 2013 by JZRIV (see edit history)

[60FlatTop]

Hi Tony, I didn't even notice it was your question. My brain is off in la-la land again. I have been watching the Sydney weather this week and your comment woke me up. Can you post the link to that good looking RHD Riviera of yours? Its been a while and I lost it.

Oh, do the easy stuff first. Check the lower hose.

Good to see your name in print,

Bernie

[fatbuick]

Hi Bernie and thanks for everyone's reply. I will work through your good suggestions and will of course post what I find for future reference.

As to my 65 Riv project, try this thread 65 Riv Project Downunder

[fatbuick]

Hi All,

Just a brief update. I have ordered a new fan clutch because the existing one is spinning too freely when compared to my 66 Wildcat.

Also, the shroud doesn't look right at the top with far too big a gap compared to the bottom. If I modify the top mounting point to bring it forward it would fix it. If anyone has a top radiator mounting piece I would be interested in buying it rather than cutting mine. Here's some pictures:

[Jim Cannon]

Tony-

Be sure to get the fan clutch with the little coil spring on the front face. The cheaper clutch with the smooth face (no coil spring) will not perform like you need.

The clutch is temperature controlled. I can hear mine engage. The fan begins to roar. I have heard it come on going down the road at 60 MPH with the A/C on. And then it cycles off again.

[Guest brivi65]

Man, I wish I had logged on to this forum sooner, I have fought an overheating problem for years now, I finally replaced the clutch last year and solved it, but it was a cheap Advanced Auto Parts one with no little spring, I just got a new one from CARS and it's made in the USA and has the spring, hopefully this will work, now 60FlatTop said something about a spring in the lower hose, I don't have one, could my hose be closing up at high speeds, this seems to be when I have the most problem?..Thanks, Brian

[fatbuick]

Just a quick update which confirms it's probably the radiator core. Put a new heavy duty fan clutch (with spring) and went for a 30 minute test drive today. It idles and runs in traffic slightly cooler but still heated up to almost 220 deg at 45 mph with a few hills.

I forgot to check the bottom radiator hose again. I'll sort the radiator out next week.

[60FlatTop]

At some point in the late 1960's I read an article that said never to lie a hydraulic clutch fan horizontally. I actually had a 1970 Chevy clutch fan in my possession for over 30 years and it always stood vertically (talk about being anal). When my Riviera was apart for about a year and a half in the 1990's the original clutch fan never tilted. It would be nice to think the fluid would settle and redistribute. I bet it doesn't. Just a thought jogged by Tony's issues and something to think about if you get one shipped.

My car had the temperature sensor fail a few years ago. It lit up hot before the engine warmed. I put a gauge on to test it and opened the hood after running or driving to diagnose it. It is still there, tie wrapped to the A/C line. I have the hood open frequently and look at it. I like it.

So the smart ass response is "Do you open the hood when you are driving? What if......" Checking the gauge frequently, having belts and hoses less than ten years old (because they are rubber), and a water pump with less than 50,000 miles and not dripping, I am pretty sure a well maintained cooling system if more reliable than the sensor that failed.

Bottom line- Keep the clutch fan vertical when its off and think about how old your belts and hoses are.

Bernie

Edited January 17, 2013 by 60FlatTop (see edit history)

[Jim Cannon]

Just a quick update which confirms it's probably the radiator core. Put a new heavy duty fan clutch (with spring) and went for a 30 minute test drive today. It idles and runs in traffic slightly cooler but still heated up to almost 220 deg at 45 mph with a few hills.

I forgot to check the bottom radiator hose again. I'll sort the radiator out next week.

Tony-

We see a lot of that in Texas in the summer.

The original heavy duty radiator in these cars had 3 rows of tubes. I put a new core in my original tanks with 4 rows of tubes. It never overheats, even in the hot summer with the A/C on. Now that you are working on your radiator, I recommend you also go with 4 rows of tubes. More money up front but worth it.

[fatbuick]

Hi Jim,

Is a 4 core physically thicker than a 2 or 3 core or does it just have more tubes within the same thickness?

There's not much space around the engine in the 1st generation Rivs which probably doesn't help. I've never felt such heat on my hand coming from the fan blades at around 200deg.

[Jim Cannon]

Hi Jim,

Is a 4 core physically thicker than a 2 or 3 core or does it just have more tubes within the same thickness?

There's not much space around the engine in the 1st generation Rivs which probably doesn't help. I've never felt such heat on my hand coming from the fan blades at around 200deg.

Well, Tony, I am not sure if the 4-row core is much thicker than the 3-row core. Talk to your radiator guy. I know it fit in my '63 without a problem, though.

Yes, these engines get really hot. And in the USA right now we have a lot of ethanol (corn whiskey) blended into our gasoline. This stuff boils so easily that it messes up the idle and vapor locks very easily.

[Guest Rob J]

I just had my radiator re-done. Just picked it up a few days ago. I found a shop that's been around since 1978 here. They told me they could not physically fit a 4 row core on my tanks without it looking awkward and non stock. I opted for the more stock appearance. Hopefully it cools sufficiently.

[fatbuick]

Update on the running hot issue. I put a spring in the lower hose and nothing has made any difference. It's only a 2 core radiator which is 2" thick and is simply not coping with the summer heat. Not worth having the radiator pulled apart and cleaned or recored here. They want $1,500 so I have ordered a new 4 core one from US Radiators for just $560 By the way it's 2-5/8" thick and will fill the gap between the shroud and core. Maybe that's why the shround is designed like that - will fit with any size core.

This car lived 41 years in Maine before I bought it so it probably never overheated there.

[60FlatTop]

Tony I just went out to the garage and confirmed that I have 75,631 miles on my car at 49 years old. I'm comparing its life to 41 years in Maine. Neither car has had to do much has it? I bought mine in April 1978, two months away from 35 years. As I remember it had something like 58,000 when I bought it (and I was 30).

So I have put 20,000 miles on it in 35 years. I remember a few years ago when I took it for inspection and had only racked up about 200 miles during the year. I was embarrassed and ashamed of myself.

I have AADD (Automotive Attention Deficit Disorder). Yeah, always two or three cars more than I need that I fart around with instead of focusing on making my keepers the best they can be and using them.

It is a thought that came to mind as I read your last post. I probably don't need to write this, but it is incurable as far as I know. Some have found a little relief from a larger garage. I hope to add two car spaces to my garage next year. On the plus side; I had a tall blonde girlfriend when I bought the Riviera. Married her and kept her, too.

Bernie

[64Riv-King]

Take a look at Centerville Auto repair's website nailheadbuick.com. They have a lot of helpful tech info:

"Cooling problemsThis is one of my most asked problems to solve. There are many reasons you could be experiencing over heating, besides all the obvious things like a radiator that is bad or plugged here are a few other things to check. Be sure the water pump impellers are very close to the inside of the timing cover. They should just touch without the gasket, timing covers are sometimes damaged by a worn out water pump in the past. In 1961 the AC cars started getting 5 impellers instead of 3 and we can custom build all 1956-1960 water pumps with 5 impellers. Ignition timing is very important so make sure it correct and vacuum advance is in good working order. I have had the outer ring of the 1957-1966 balancers spin on the inner section so you think the timing is right but it is not. Buick also started using a smaller water pump pulley in 1962 on AC cars, those pump more water by over driving the water pump and fan to 1.2 . These smaller pulleys must always use a clutch type fan and a fan shroud. It is also possible to pump too much coolant through the radiator too fast, No thermostat is one way that can happen or too small of a radiator is another. Remember that all the air that goes through the radiator MUST get out of the engine compartment. Another very common problem is rust plugging up the radiator AFTER a rebuild. The new hot tanks DO NOT remove chunks of rust, you think because the block and heads were "tanked" and cleaned all the rust was gone. It has happened so many times to us we started putting in a radiator filter inside the upper radiator hose. We use about an 8" square piece of panty hose (ask the wife first! LOL) put it over the upper radiator fitting, push the center into the fitting creating a pocket, the outer part the panty hose filter goes on the outside of the fitting and upper hose slides one holding the filter in place. You will be amazed at all the rust chunks you can keep out of the radiator. Clean often and remove the filter before driving a long distance where it could get plugged up and fry your engine!. Aluminum Radiators DO NOT cool as well as brass/copper ones do and when the aluminum ones get plugged you can't just tack the tanks off to clean, they are welded together. Last thing is coolant, use 50/50, half distilled water. Coolant bottle is helpful to keep that radiator filled".

[fatbuick]

Just a quick update. Got my new radiator last week from US Radiator and thoroughly recommend these guys. It fitted perfectly and well packed.

The good news is I cannot get it to go over 190deg with a 180deg thermostat now so it has made the difference I needed.

There is still a gap between the shroud and core at the top of about 3/8" but I will fix that by modifying the top bracket.

[DualQuadDave]

4 Core upgrade is the only way to go. I have a local shop that does cherry 4 core conversions on the stock tanks. Looks near invisible when done. I will post pics this weekend. Not a cheap mod, but 110% necessary if you intend to drive your Riv. IMO, the factory radiator was never adequate, at least not in hot climate like SoFlo.

[Mr Riviera]

I just had my radiator re-done. Just picked it up a few days ago. I found a shop that's been around since 1978 here. They told me they could not physically fit a 4 row core on my tanks without it looking awkward and non stock. I opted for the more stock appearance. Hopefully it cools sufficiently.

All those years in the business and still dont know what they are talking about ! I always replace with 4 row and use the old upper and lower tanks .

[fatbuick]

Sorry I didn't update you with the results of the 4 core radiator installation. Basically it solved all my problems and runs between 180 and 190 in all conditions.

[Guest brivi65]

Wow Tony, that is great news, I think I will be placing a call to US Radiators for a 4 core, mine is still heating up to 220deg over 45 MPH and then back down to 190 at a stop light, the exact opposite of any other old car I've ever had! Did you get the Standard Automotive core , or the High Efficiency core? I see there is an option on their website, not sure what the difference is, but with the 4 core High Efficiency it's $568.00 plus shipping, worth it if I can actually drive the Rivi more than 20 miles without stopping for 20 minutes!:mad: Brian

[Jim Cannon]

Wow Tony, that is great news, I think I will be placing a call to US Radiators for a 4 core, mine is still heating up to 220deg over 45 MPH and then back down to 190 at a stop light, the exact opposite of any other old car I've ever had! Did you get the Standard Automotive core , or the High Efficiency core? I see there is an option on their website, not sure what the difference is, but with the 4 core High Efficiency it's $568.00 plus shipping, worth it if I can actually drive the Rivi more than 20 miles without stopping for 20 minutes!:mad: Brian

Brian-

What do you know about the age and condition of your fan clutch?

The symptoms you describe are classic bad fan clutch. Or someone put the "economy model" fan clutch on in the past when the OEM one failed. You need the one with the coil spring on the front face and it needs to work. When it works, the fan ROARS at higher RPM. With the hood up and the engine very hot, rev the engine up by hand (operate the throttle under the hood) and you should hear it roar. If not, the clutch is bad.

You may also need a new radiator, I'm not saying you don't. But start with the basics.

SW Florida will have summer weather like Texas. I have had guys have problems here with new 3-row core radiators. They swap them out with a new 4-row and no problems.

I recommend the high efficiency core. It is probably more fins per inch, compared to the other core. You can never have too much radiator in a hot weather location (as long as you have a thermostat installed for the cooler times of the year).

[Guest brivi65]

Hello Jim, I have been fighting this for about 4 years now, since I've been actively driving it, I had a local radiator shop that's been around since the 60's build the radiator 3 core with my existing tanks, seemed OK, still hovered around 205 deg, so replaced t-stat, no change, hoses, no change, I then bought a fan clutch at Advanced Auto Parts, Chinese and with out the spring. I have since bought a new clutch through CARS at it is made in the USA with a spring, again helped a little but it is definitely working as I hear it roaring on load, but I am in agreement with you, I believe I need to get a 4 core High Efficiency radiator and be done with it so I can get back to enjoying a Rivi trip and I can stop smelling that wretched anti freeze! I HATE THAT SMELL!! Brian

[Jim Cannon]

Hello Jim, I have been fighting this for about 4 years now, since I've been actively driving it, I had a local radiator shop that's been around since the 60's build the radiator 3 core with my existing tanks, seemed OK, still hovered around 205 deg, so replaced t-stat, no change, hoses, no change, I then bought a fan clutch at Advanced Auto Parts, Chinese and with out the spring. I have since bought a new clutch through CARS at it is made in the USA with a spring, again helped a little but it is definitely working as I hear it roaring on load, but I am in agreement with you, I believe I need to get a 4 core High Efficiency radiator and be done with it so I can get back to enjoying a Rivi trip and I can stop smelling that wretched anti freeze! I HATE THAT SMELL!! Brian

Sounds like a plan.

Do you have an overflow bottle? If not, you should add one with the new core. That, plus use demineralized water with your antifreeze. It will keep the radiator like new inside.

[Guest brivi65]

Yes I need a overflow tank for sure, my car tends to mark its territory! Thanks Jim for the tip on the water! Brian

[1965rivgs]

Wow Tony, that is great news, I think I will be placing a call to US Radiators for a 4 core, mine is still heating up to 220deg over 45 MPH and then back down to 190 at a stop light, the exact opposite of any other old car I've ever had! Did you get the Standard Automotive core , or the High Efficiency core? I see there is an option on their website, not sure what the difference is, but with the 4 core High Efficiency it's $568.00 plus shipping, worth it if I can actually drive the Rivi more than 20 miles without stopping for 20 minutes!:mad: Brian

Brian, If your car was hot while at idle (air flow depends on fan/shroud) and cooled off while underway (plenty of airflow via road speed) I would suspect an air flow problem. But your problem is just the opposite and points to cooling system efficiency/capacity. Under normal circumstances I would suspect a clogged radiator but you have recored same, correct?. Although I recognize a 4 core unit would enable you to run cooler while at a standstill I would expect a new 3 core rad to do an adequate job while underway, even in extreme temps.

Confirm your actual temp with a mechanical gauge or another means like a tank top thermometer (probably not possible or very smart when running at a temp close to boiling) or a point and shoot temp gun. Make sure your belts are adjusted properly. Take a good look at your water pump. Be sure the impeller is not slipping on the shaft; granted this is a long shot but I have experienced this twice. Good luck,

Tom Mooney

[fatbuick]

[TABLE=class: data-table]

<tbody>[TR]

[TD=class: label]These are the details of the radiator I purchased:

Part Number

[/TD]

[TD=class: data]005070AADZ[/TD]

[/TR]

[TR]

[TD=class: label]Material[/TD]

[TD=class: data]Copper/Brass[/TD]

[/TR]

[TR]

[TD=class: label]Factory AC[/TD]

[TD=class: data]Yes[/TD]

[/TR]

[TR]

[TD=class: label]Rows[/TD]

[TD=class: data]4 Rows[/TD]

[/TR]

[TR]

[TD=class: label]Core Size[/TD]

[TD=class: data]17-3/8 x 24-3/4 x 2-5/8[/TD]

[/TR]

[TR]

[TD=class: label]Core[/TD]

[TD=class: data]High Efficiency[/TD]

[/TR]

[TR]

[TD=class: label]Core Description[/TD]

[TD=class: data]4 rows of 1/2" tubes on 3/8" centers. 20% more heat transfer points over a 4 row "Standard Automotive Core" without changing the thickness of the core.[/TD]

[/TR]

[TR]

[TD=class: label]Flow Type[/TD]

[TD=class: data]Downflow (Tanks on top and bottom)[/TD]

[/TR]

[TR]

[TD=class: label]Inlet Size[/TD]

[TD=class: data]1-1/2"[/TD]

[/TR]

[TR]

[TD=class: label]Outlet Size[/TD]

[TD=class: data]1-1/2"[/TD]

[/TR]

[TR]

[TD=class: label]Transmission Cooler Size[/TD]

[TD=class: data]12-1/2x3/8 IF[/TD]

[/TR]

[TR]

[TD=class: label]Manufacturer[/TD]

[TD=class: data]U.S. Radiator[/TD]

[/TR]

</tbody>[/TABLE]

[arnulfo de l.a.]

tom,

when you use a point and shoot temperature reader, where do you point and shoot? radiator,heads , block or all?

gracias,

arnulfo