Jump to content

Overheating problem diagnosis as per service manual


RivNut
 Share

Recommended Posts

We see a lot of questions about overheating and the cooling system.  I was looking for one thing in the service manual and found this.  It's well worth reading and digesting.  This is for the 401/425 engines using the recommended 180 degree thermostat.

1. Excessive water loss. 

2. Slipping or broken fan belt

3. Radiator thermostat stuck, radiator air passages clogged, restriction in radiator core, hoses, or water jacket passages

4. Improper ignition timing.

5. Improper carburetor adjustment.

6. Exhaust manifold valve stuck.

7. Shortage of engine oil or improper lubrication due to internal conditions.

8. Dragging brakes.

 

Lots of things to consider.

  • Like 6
Link to comment
Share on other sites

I am on many forums and it is always amusing to see how the first responses to a question about overheating involve ripping out the stock parts and adding an aluminum radiator, low temp thermostat, electric fans, aftermarket water pump, etc. When I added the Vintage Air system to my factory air 63 years ago, the custom shop that I bought it from told me not to change anything including the 180 stat, saying their experience was that correctly operating factory systems were superior. I followed their advice and never had a cooling problem and can say the same about at least three other cars since then.

  • Like 4
Link to comment
Share on other sites

6 hours ago, TexRiv_63 said:

followed their advice and never had a cooling problem and can say the same about at least three other cars since then.

TexRiv_63, I’m happy to learn everything went according to the Service manual. The Service manual info remains static, other than TSB Bulletins. However, the car and and everything in it has gotten older. I’ve changed my cooling system around with a 160 degree thermostat, severe duty one ton fan clutch, a shroud, and a very well hidden coolant overflow tank, and the original radiator recore. The engine was completely dismantled and rebuilt by JB Engine Machines Rosedale, Md. I’m happy with the results. Trust me - if it is working I leave it alone.

The manual sometimes makes errors. For instance the specs in my 63?Service manual says the A6 Compressor and AC system needs 3.5 lbs of R12. Those mechanics in the know on the forum said the system requires 4lbs of R 12 maybe a tad more. In this case the manual was mistaken as my 63 AC system performs much better with 4lbs of R12. I’m of the belief these cars take on operating characteristics that differ from car to the next. The differences are very small, but none less different.

The differences are a result of wear patterns that vary from one car to the next. Put on new OEM parts or aftermarket parts and the stress and strains are new to the parts that work with the new part. Using the Service Manual is essential for me. But I’ve experienced tweaking the service manual’s service procedure may be necessary. Two examples are: substituting the vacuum water control valve for the no longer produced manual control valve, next using a single dual port vacuum actuator for the #3 and#4 vacuum actuators on the 63 AC system. Additionally, the Suction Throttling valve has been replaced with by pass system and electronic cycling switch. The Service Manual tells you how to rebuild the STV, but I had no luck. 
Turbinator

Link to comment
Share on other sites

I changed to a 160 thermostat, thinking it would help run cooler. I finally realized that the thermostat is there to maintain a minimum operating temperature. 

After installing a temperature gauge I thought my car was running too warm on hot days. I would sometimes run 205 - 210 degrees. 

The Service manual says the hot light doesn't come on till after 240 degrees. 

The car was fine. The problem was in my head.

 

Kevin 

  • Like 1
  • Haha 2
Link to comment
Share on other sites

15 hours ago, Turbinator said:

TexRiv_63, I’m happy to learn everything went according to the Service manual. The Service manual info remains static, other than TSB Bulletins. However, the car and and everything in it has gotten older. I’ve changed my cooling system around with a 160 degree thermostat, severe duty one ton fan clutch, a shroud, and a very well hidden coolant overflow tank, and the original radiator recore. The engine was completely dismantled and rebuilt by JB Engine Machines Rosedale, Md. I’m happy with the results. Trust me - if it is working I leave it alone.

The manual sometimes makes errors. For instance the specs in my 63?Service manual says the A6 Compressor and AC system needs 3.5 lbs of R12. Those mechanics in the know on the forum said the system requires 4lbs of R 12 maybe a tad more. In this case the manual was mistaken as my 63 AC system performs much better with 4lbs of R12. I’m of the belief these cars take on operating characteristics that differ from car to the next. The differences are very small, but none less different.

The differences are a result of wear patterns that vary from one car to the next. Put on new OEM parts or aftermarket parts and the stress and strains are new to the parts that work with the new part. Using the Service Manual is essential for me. But I’ve experienced tweaking the service manual’s service procedure may be necessary. Two examples are: substituting the vacuum water control valve for the no longer produced manual control valve, next using a single dual port vacuum actuator for the #3 and#4 vacuum actuators on the 63 AC system. Additionally, the Suction Throttling valve has been replaced with by pass system and electronic cycling switch. The Service Manual tells you how to rebuild the STV, but I had no luck. 
Turbinator

All very true. My Riv was all original with over 85,000 miles on it and the engine appeared to have never been apart. The radiator was repainted so it probably been serviced at some point. Admittedly I was probably very lucky!

Link to comment
Share on other sites

3 hours ago, kegart said:

After installing a temperature gauge I thought my car was running too warm on hot days. I would sometimes run 205 - 210 degrees. 

The Service manual says the hot light doesn't come on till after 240 degrees. 

The car was fine. The problem was in my head.

 

Kevin 

Very true! I was chasing an overheating problem on a 67 GTX, the SW Green Line gauge said it was hot but the factory gauge was still in the middle. Turned out the key was not the number of degrees but whether or not the temp stabilized when the car was moving.

Link to comment
Share on other sites

On 8/17/2021 at 1:06 PM, TexRiv_63 said:

I am on many forums and it is always amusing to see how the first responses to a question about overheating involve ripping out the stock parts and adding an aluminum radiator, low temp thermostat, electric fans, aftermarket water pump, etc. When I added the Vintage Air system to my factory air 63 years ago, the custom shop that I bought it from told me not to change anything including the 180 stat, saying their experience was that correctly operating factory systems were superior. I followed their advice and never had a cooling problem and can say the same about at least three other cars since then.

My 73k mile '65 has had a water pump at some point, and possibly a thermostat; not sure because I haven't taken it apart. My radiator still has the original warning sticker on the driver's side  of the upper tank. All I have done is a coolant flush, and replaced the radiator cap with a correct reproduction from CARS. I have Vintage Air as well, that replaced my factory a/c setup, and have never had overheating issues in six years of ownership.

  • Like 1
Link to comment
Share on other sites

1 hour ago, TexRiv_63 said:

was hot but the factory gauge was still in the middle. Turned out the key was not the number of degrees but whether or not the temp stabilized when the car was moving.

Sir, after the engine is quite hot and the temp gauge says 185-190 degrees and I stop the car something and park the temp sitting still goes up 210 degrees. I start the car and begin to drive and temp goes down..

Most of time owners just have to know what to do and what not to do. Like I said if it is working I’ll leave it alone. My radiator was puking out coolant when I stopped the car. One of my friends said you have too much fluid in the radiator. I put on a 2 L coolant tank inside drivers lower right wheel well. Fits good. No more coolanth puking all over the place.

Actually most everything was alright until I started messing with the AC replacement. Then to add to that after I had the engine rebuilt I did not quite get the cooling system hooked up quite right after the newly rebuilt engine was put in. Well, having gone through all that it could be quite possible I didn’t have to do a thing! The good thing is the car works fine now. The AC sprung another leak, but it is being fixed.

Edited by Turbinator (see edit history)
  • Like 1
Link to comment
Share on other sites

15 hours ago, RivNut said:

Curiously, why did you change to a 160 degree thermostat?

Ed, at first I had a thermostat with a higher temp than 180, I thought the car was running hot. So I put in a 180 thermostat. Still too hot for me. Next I moved down to a 160 thermostat and 7 lb radiator cap. Everything is fine as wine. I made the changes on trial and error even after I read the manual.

Link to comment
Share on other sites

Bob, 

Can you tell me where to find that info in the manual?  In general science class we learned that you only changed one variable at a time. Changing two at a time never breaks down which change made the difference.  Did toy do anything else around the same time?  

Link to comment
Share on other sites

12 hours ago, RivNut said:

Bob, 

Can you tell me where to find that info in the manual?  In general science class we learned that you only changed one variable at a time. Changing two at a time never breaks down which change made the difference.  Did toy do anything else around the same time?  

Ed, No toying around. When coolant was shooting out from radiator cap I figured something wasn’t right. I tested the radiator cap and made a change. Coolant still came out from the radiator cap. I made sure I had the thermostat in correctly. Thermostat in correctly, so changed it out until I got to 160 thermostat. The coolant stopped spewing from under the radiator cap when engine was turned off after driving for a period. I figured the problem was solved.

The purpose of the severe duty fan clutch was an effort to draw more air in over the engine. The severe duty fan clutch runs 80 percent of the time.

The shroud helps to direct the air toward the engine to help keep the engine cool. I also corresponded with a gent who lives in AZ who owns a Riviera and he told me the higher temp thermostat was too much for his engine., The gent said he used a 160 thermostat. I vaguely remember my Dad telling me you are suppose to change the thermostat with change in the season.The reason I went to 7lb radiator cap is because the gent who has been rebuilding radiators his whole life recommended the 7 lb cap was better for the radiator. Since I had the car I’ve three radiator leaks they have been repaired. The 7 lb cap works fine.

You are right fixing one problem at a time and test before you try something else makes good sense. The over heating was a problem that has been a problem since I owned the car. Now what I mean by over heating was coolant was spewing from the radiator cap after driving the car and the car engine turned off when I reached my destination.

I have the temp gauge installed so I can watch the temp. I like having the temp gauge. Maybe the engine runs a bit hotter after a rebuild. I must have missed the section in the manual about the engine overheating after a rebuild.

Anything automotive I usually have to work pretty hard to get it right the first attempt at repair. So far it has been an adventure in maintaining the Riv. My pal Tom Telesco has coached me on many small repairs. Tom has even worked on my car and made corrections on my work such as showing me the correct way to install a cotter pin, or install a ground wire. I’m making progress and I might say I’m delighted with my Riviera 😊

The forum has been a great help in helping me to fix up my car. There are many, such as yourself, offer quite a bit of help that I truly appreciate.

Turbinator

  • Like 2
Link to comment
Share on other sites

Another thing I have done on every car I've had since the Riv is add a coolant RECOVERY system. a 16 lb vented cap, small reservoir tank and some tubing, easy. Lets you fill the radiator all the way to the top and stops the "puking" problem. Yes, I know it's a modification but if you drive your car it makes sense to me.

Link to comment
Share on other sites

7 hours ago, Turbinator said:

Ed, No toying around. When coolant was shooting out from radiator cap I figured something wasn’t right. I tested the radiator cap and made a change. Coolant still came out from the radiator cap. I made sure I had the thermostat in correctly. Thermostat in correctly, so changed it out until I got to 160 thermostat. The coolant stopped spewing from under the radiator cap when engine was turned off after driving for a period. I figured the problem was solved.

The purpose of the severe duty fan clutch was an effort to draw more air in over the engine. The severe duty fan clutch runs 80 percent of the time.

The shroud helps to direct the air toward the engine to help keep the engine cool. I also corresponded with a gent who lives in AZ who owns a Riviera and he told me the higher temp thermostat was too much for his engine., The gent said he used a 160 thermostat. I vaguely remember my Dad telling me you are suppose to change the thermostat with change in the season.The reason I went to 7lb radiator cap is because the gent who has been rebuilding radiators his whole life recommended the 7 lb cap was better for the radiator. Since I had the car I’ve three radiator leaks they have been repaired. The 7 lb cap works fine.

You are right fixing one problem at a time and test before you try something else makes good sense. The over heating was a problem that has been a problem since I owned the car. Now what I mean by over heating was coolant was spewing from the radiator cap after driving the car and the car engine turned off when I reached my destination.

I have the temp gauge installed so I can watch the temp. I like having the temp gauge. Maybe the engine runs a bit hotter after a rebuild. I must have missed the section in the manual about the engine overheating after a rebuild.

Anything automotive I usually have to work pretty hard to get it right the first attempt at repair. So far it has been an adventure in maintaining the Riv. My pal Tom Telesco has coached me on many small repairs. Tom has even worked on my car and made corrections on my work such as showing me the correct way to install a cotter pin, or install a ground wire. I’m making progress and I might say I’m delighted with my Riviera 😊

The forum has been a great help in helping me to fix up my car. There are many, such as yourself, offer quite a bit of help that I truly appreciate.

Turbinator

You are a class act  Bob! I have not had ANY overheating issues with my 65 .  No puking or idiot light on. Original radiator rodded once  in 2008. I think a big part of an engine running cool is that there not be any type of build up in the blocks water pocket Walls as well as everything else being up to par. 

Link to comment
Share on other sites

Strange.  It must me much hotter now than it was between 1982 (when I bought my '63) and 2002 (when it was too tired to continue (197,000 miles)) because in those 20 years I never had a cooling problem running what the factory installed on the assembly line.  No special radiator, no special radiator cap, no puke can.  I guess that Global Warming is affecting the old car crowd.  My engine would get hot enough to cause the starter motor to seize, cured by rebuilding the starter to hi-torque specs, but never any loss of coolant.  

  • Haha 1
Link to comment
Share on other sites

Ed, I’ve never heard you write about the Riviera you are driving today. I know you have a collection of good cars. Do you not drive your First gen Riviera that much it just does not  cause any problems.? 
I certainly do not make this stuff up. If the car needs attention I make a valiant effort to correct the problem.

Sometimes successfully,most times I have to do the repair over again and again until I get it right. 
You never complain about your vintage ride. You know a lot and certainly able to fix the the vehicle.

Here is a recent picture of my zRiviera. Show a recent picture of your fine Riviera. With all your genuine knowledge I’m certain you have a recently dated photo of your chariot.

94E0BCA1-61A7-4AEE-97DC-C8CAB537B39F.jpeg

  • Like 1
Link to comment
Share on other sites

5 hours ago, TexRiv_63 said:

Yes, I know it's a modification but if you drive your car it makes sense to me.

TexRiv, my coolant tank is well hidden. I’ve used 16lb cap and it stopped running hot. The radiator man said Try the 7lb. Cap.I said ok. It doesn’t run hot any longer with the 160 thermostat or 7 or 16 lb thermostat. 

Go figure.

Turbinator

  • Like 1
Link to comment
Share on other sites

I wish that I did.  A short long history of my 1st generation Riviera’s.  I got divorced in 1997 and because the Riviera was my daily driver but not what I’d call a family car I parked it with 197K on the clock.  I bought a newer car that I could afford that I could drive in inclement weather and such.  Without that 2nd income, it just sat in the garage. I remarried in 2002 and my new family came with two young boys.  I was now in a totally new environment with new priorities so the 63 continued to sit.  Around 2005 a friend in AZ asked me if he thought the engine in “this 64 Riviera” would be a good motor for his ‘52 Buick Super.  Turned out he found an engine and wouldn’t need to buy the 64 just for the engine.  I went to the 2005 ROA meet in Flagstaff and found time to go to Prescott to check out the 64.  It ran fine put the AZ sun had ruined the paint and interior.  I bought it and arranged to have it shipped to KC. When it arrived, I drove it “as is” for a couple of years.  Now with finances in order, I had to make a choice - the 1963 or 5he 1964.  The 64 was running and I thought it would be less $$ to redo it.  I contacted a young guy just getting into the restoration business and took the car into his shop.  We found that the car had been in at least one accident and was in poor condition under the paint. In some places the Bondo was 1/4” to 3/8” thick.  Tim Nugent had a parts car and I got a lot of body parts from him. We got the body in good shape and I decided to gut the interior and do some engine work. About time to put everything back together and the kid sold his business and moved in with another guy.  I brought the car home, moved the 63 into a friends warehouse about 70 miles from me and put the 64 into the #3 garage.  That was about the same time that my ankle started acting up and I was having a problem standing. I’d been treating it as arthritis but it turned out to be OCD (osteochondritis dissecans) of the talus - a hole in my ankle bone where the shin bone meets the foot bone.  Surgery has now corrected that.  Then the costochondritis hit and for another year I couldn’t flex any muscles in my chest.  FINALLY in the past three to four months I’m feeling healthy enough to get back into the garage.  My stepson, who was the hands on guy, is to a point where he can help me put everything back together.  We’re now trying to account for all the nuts and bolts. Most engine bolts have been accounted and we’re cleaning the as well as running thread chasers through and around everything.  He has about 3 hours per day that he can give me and after that the heat gets to us.  I’m looking at another 200 hours to put everything back together correctly making sure that we don’t take any short cuts.  Then paint and upholstery.  Maybe ready for Branson?  The 1965 Gran Sport has not moved since I bought it. It’s in the same warehouse as the ‘63.  - I basically bought it because it was cheap ($3,000) for an investment.  Time and health had not been kind to me but I’m now ready to make up for lost time doing what I can (on my severely reduced fixed income.)  I’ll post a picture of the ‘64 in its current state - not pretty but it’s nice and solid now.   During this same time span I’ve bought and restored two 1983 Anniverary XX Rivieras, a 93 Riviera, an 84 coupe, an 85 coupe, an 84 convertible, and a 95 Riviera.  A couple of El Camino, and a 1970 Buick Skylark sport coupe.  Those didn’t require any of the heavy restoration work, just easy cosmetics and interior stuff. Required some time but no “heavy lifting.”  It feels good to be back into the hands on part of the hobby.

  • Like 3
Link to comment
Share on other sites

20 hours ago, RivNut said:

Strange.  It must me much hotter now than it was between 1982 (when I bought my '63) and 2002 (when it was too tired to continue (197,000 miles)) because in those 20 years I never had a cooling problem running what the factory installed on the assembly line.  No special radiator, no special radiator cap, no puke can.  I guess that Global Warming is affecting the old car crowd.  My engine would get hot enough to cause the starter motor to seize, cured by rebuilding the starter to hi-torque specs, but never any loss of coolant.  

Looks like we were both lucky! I think the biggest reason some people throw lots of modification at an old car problem is the - INTERNET. I first noticed this in the late 90s - early 2000s when I was playing with 1994-96 Chevy Caprice cop cars. I got on a forum for those and the Impala SS models and could not believe the massive interest in modifying these not-very-old-at- the time cars. Turned out it was almost totally due to the forums, there was some good info there but probably 75% was garbage and owners just followed along. Still the same today only much more pervasive.

Link to comment
Share on other sites

12 hours ago, TexRiv_63 said:

Turned out it was almost totally due to the forums, there was some good info there but probably 75% was garbage and owners just followed along. Still the same today only much more pervasive.

I must agree. It takes ability to determine what is wasteful and  what truly helps the car run better. For My Riv sway bars make cornering more comfortable for me. Electronic ignition makes for better start up. The puke tank cleans up a mess. The battery cut off switch keeps me from blowing fuses when I do electrical work. I liked having my steering box rebuilt so I could feel the front tires on the road. I thought a dual master brake cylinder added Safety to the car.

Some stuff can be truly wastefu all of us are subject to some persuasive advertising. Buyer beware.

Turbinator

  • Like 1
Link to comment
Share on other sites

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 account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...