1989 C3500 4x4 454 always runs hot

I've done a lot of work to be sure their are no problems with the Fan Clutch, Radiator or Thermostat, yet this 454 with throttle body injection always runs hot when towing. 240-270 It can get to the red line and beyond when pulling a steep hill on a hot day. The power is not good on those days and I don't run with the throttle mashed down. It runs hot on hot days when not towing also. I'm considering an oil cooler and would like to do it the right way if I do. I'm looking for links, advice, other peoples experiences with their projects. I'm my own mechanic and body man not afraid to tackle a major change to the engine or body. Though I'd like to keep this truck fairly stock on the outside. The engine runs very well, though it seems to lack power for a big block. I will consider an engine overhaul with performance enhancements if someone can turn me on to the right combination of ingredients.

Reply to
mlemke
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If you are absolutely certain you have a radiator with enough capacity in good condition. A seven blade flex fan will pump considerably more air possibly at the expense of a little fuel mileage. The ignition timing being retarded can cause hotter than normal running. Light weight motor oil can make it run hotter. You can run 20w50 oil year round it will help keep it cooler. An oil cooler is a good idea for anything that pulls heavy loads. Another often overlooked item is the a/c condenser. I've cured a few hot running vehicles just by cleaning the fins out on the condenser at the local high pressure car wash.

nobody #1

Reply to
nobody #1

2 years ago I re-cored with a custom 5 layer core in the radiator. The result was no heating up on mild days except when towing. The AC condenser is clean. The fan clutch is heavy duty enough the engine howls, but this is re-assuring as the engine no longer heats up while not towing. I'm told the reason there was no 4 or 5 speed option for the one ton in 89 is the cooling issue. I really would like to talk with someone who has overcome this by any combination of engine and or cooling mods.
Reply to
mlemke

I guess you could put a small block in it. That's an engine mod that will certainly fix it. There is no magic bullet. You're looking for something that doesn't exist.

nobody #1

Reply to
nobody #1

The exhaust is restricted.

Al

Reply to
Big Al

What about an electric cooling fan .

Reply to
None4U

2 years ago I re-cored with a custom 5 layer core in the radiator. The result was no heating up on mild days except when towing. The AC condenser is clean. The fan clutch is heavy duty enough the engine howls, but this is re-assuring as the engine no longer heats up while not towing. I'm told the reason there was no 4 or 5 speed option for the one ton in 89 is the cooling issue. I really would like to talk with someone who has overcome this by any combination of engine and or cooling mods.

My 35 years of experience as a GM parts guy (retired now) seem to recall that there are two different part numbers for the fan clutch on the 454 big block - depending on the rear end ratio. I believe that all vehicles with a ratio of 2.73 thru 3.23 take one fan clutch and vehicles with the 3.73 ratio use another part number. This is because the engine is turning higher RPMs with the 3.73 ratio rear end and the clutch must slip more in order to not rob horse power by pulling an excessive amount of air through the radiator. I seem to remember something about moving air too fast through the radiator causes disruption of the air flow and therefore would not cool adequately.

If your vehicle was built with the factory towing package, I'm pretty sure that your vehicle has either the 3.23 or 3.73 rear end ratio. You need to determine which one you have. Look at the option label and find the option that starts with either GT or GU. You should be able to do an internet search on "GM rear end ratio" and determine what ratio your vehicle has installed.

If you purchased the fan clutch from a parts store (not a dealer), many times the aftermarket supplier only lists one part number for the application. If you purchased the fan clutch from an AC-Delco parts store and actually purchased an AC-Delco fan clutch, chances are you purchased the correct one because the parts book would list both. When you purchased the fan clutch, did the parts person state that there were two different part numbers listed and explain how to determine which one you needed to purchase?

As to the 20W50 recommendation, that will also rob horse power and retain heat due to the heavier viscosity. You might consider using AMSOIL 5W30 Synthetic. AMSOIL synthetics dissipate heat faster than any other oil - regular or synthetic - and will keep the crankcase up to 50 degrees F cooler when compared to other lubrications.

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Used together with AMSOIL's Synthetic Nanofiber Technology Oil Filter, you can use the same oil and oil filter for 25,000 miles of normal use.

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AMSOIL even has a synthetic nanofiber technology By-Pass Filter System that will filter particles as small as 1 micron and keep the oil analytically clean for up to 60,000 miles. Engine wear is caused primarily by particles between 1 and 2 microns in size. By using a By-Pass Filter, you can keep engine wear to a minimum by filtering out and trapping particles of damaging size.

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If you have any other questions, please don't hesitate to email me directly. I usually respond to inquiries within 2 to 4 hours unless I'm away from my PC.

Reply to
Steve

You're an Amsoil salesman what do you know about keeping a big block chevy cool. You were a parts guy and you may know what fits what in the gm parts world. I can tell you you don't know shit about big blocks and overheating problems, oil temperatures, coolant temperatures and the effects of replacing a light weight passenger car oil with a non starburst c or cf rated 20w50 oil on them. I can also tell you all of the parts stores sell at least three different fan clutches for that vehicle and you can buy all three of them for what one gm fan clutch will cost. Any one of the three will likely do the job just as well as the Mexican manufactured over priced GM product.

Amsoil's recommendation to go 25K between changes is ridicules. Their nano whatever 1 micron filter is a bypassing filter because at 5K miles it's completely plugged and has to bypass or risk starving the engine for oil. Amsoil is nothing but a bunch of hype and marketing to steal money from stupid people that are willing to pay too much money for benefits they'll never see.

nobody #1

don't bother to reply I now really don't give a f*ck what you think.

Reply to
nobody #1

| > If your vehicle was built with the factory towing package, I'm pretty | > sure that your vehicle has either the 3.23 or 3.73 rear end ratio. | > You need to determine which one you have. Look at the option label | > and find the option that starts with either GT or GU. You should be | > able to do an internet search on "GM rear end ratio" and determine | > what ratio your vehicle has installed. | >

| > If you purchased the fan clutch from a parts store (not a dealer), | > many times the aftermarket supplier only lists one part number for the | > application. If you purchased the fan clutch from an AC-Delco parts | > store and actually purchased an AC-Delco fan clutch, chances are you | > purchased the correct one because the parts book would list both. | > When you purchased the fan clutch, did the parts person state that | > there were two different part numbers listed and explain how to | > determine which one you needed to purchase? | >

| > As to the 20W50 recommendation, that will also rob horse power and | > retain heat due to the heavier viscosity. You might consider using | > AMSOIL 5W30 Synthetic. AMSOIL synthetics dissipate heat faster than | > any other oil - regular or synthetic - and will keep the crankcase up | > to 50 degrees F cooler when compared to other lubrications. | >

| >

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| >

| > Used together with AMSOIL's Synthetic Nanofiber Technology Oil Filter, | > you can use the same oil and oil filter for 25,000 miles of normal | > use. | >

| >

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| >

| > AMSOIL even has a synthetic nanofiber technology By-Pass Filter System | > that will filter particles as small as 1 micron and keep the oil | > analytically clean for up to 60,000 miles. Engine wear is caused | > primarily by particles between 1 and 2 microns in size. By using a | > By-Pass Filter, you can keep engine wear to a minimum by filtering out | > and trapping particles of damaging size. | >

| >

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| >

| > If you have any other questions, please don't hesitate to email me | > directly. I usually respond to inquiries within 2 to 4 hours unless | > I'm away from my PC. | >

| | | | | You're an Amsoil salesman what do you know about keeping a big block | chevy cool. You were a parts guy and you may know what fits what in the | gm parts world. I can tell you you don't know shit about big blocks and | overheating problems, oil temperatures, coolant temperatures and the | effects of replacing a light weight passenger car oil with a non | starburst c or cf rated 20w50 oil on them. I can also tell you all of | the parts stores sell at least three different fan clutches for that | vehicle and you can buy all three of them for what one gm fan clutch | will cost. Any one of the three will likely do the job just as well as | the Mexican manufactured over priced GM product. | | | Amsoil's recommendation to go 25K between changes is ridicules. Their | nano whatever 1 micron filter is a bypassing filter because at 5K miles | it's completely plugged and has to bypass or risk starving the engine | for oil. Amsoil is nothing but a bunch of hype and marketing to steal | money from stupid people that are willing to pay too much money for | benefits they'll never see. | | | | nobody #1 | | don't bother to reply I now really don't give a f*ck what you think. | |

Mr. Nobody#1::

You are very good at innuendos and accusations; however you have not provided any proof for any of your statements.

You've also misstated the facts I offered above by stating that "Their nano whatever 1 micron filter is a bypassing filter because at 5K miles it's completely plugged and has to bypass or risk starving the engine for oil". The By-Pass Filter System is, in fact, a synthetic nanofiber technology filter that is rated to be used for up to 60,000 miles and continuously filter particles down to 1 micron in size - therefore keeping the oil analytically clean.

You can read about the Synthetic Nanofiber Technology here:

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Be sure to read all the way to the bottom of the page. It explains how the synthetic nanofiber keeps the filter from plugging, offers superior filtration when compared to cellulose filters, and how the filter maintains full flow to provide engine lubrication throughout the full 25,000 miles.

The starburst symbol to which you refer is the A.P.I. logo and oils that have the A.P.I. licensed logo only need to meet the minimum specifications for each rating in order to use the A.P.I. logo on the product. See the 2nd link below for affirmation of this statement.

AMSOIL manufactures engine lubrications which meet the A.P.I. specifications for those that need to be reassured by the A.P.I. certification. The link just below this paragraph points to a 5W-30 engine oil that meets the A.P.I. specification and is rated for use up to 7,500 miles OR up to 12,000 on engines with oil life monitoring or upon factory recommendation.. AMSOIL also offers A.P.I. rated engine lubricants in 5W-20, 10W-30 and 10W-40.

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Although the XL oils are a very fine quality lubricant, they are not the best quality lubricants that AMSOIL offers. AMSOIL addresses the subject of why their best products - the 25,000, 35,000 and continued use based on oil analysis - are not A.P.I. certified. If you care to actually read the article, here is the link:

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AMSOIL has spent millions on Research & Development and have been in business touting extended oil drain intervals since 1972. If AMSOIL was being untruthful or deceptive, they wouldn't still be in business.

Continue to change your oil at 3,000 mile intervals OR learn how the oil companies have been promoting 3,000 mile oil changes just to prop up their bottom line.

Here is a comparison of 3,000 mile petroleum oil changes to AMSOIL's

25,000 mile oil change.

It would take 8 oil changes at 3,000 mile intervals to equal 24,000 miles. Each 3,000 mile oil change will average $30.00 to have it done at Jiffy Lube or equivalent That's a total of $240.00 You have to make 8 trips to get the oil and filter changed. There are 8 changes X 5 quarts = 40 quarts of waste oil to be recycled. Even if you can get it done for $19.95 per change, that is still $159.60.

Now, if you used AMSOIL, 5 quarts of ASL 5W-30 Oil which is engineered to perform for 25,000 costs $8.75 per quart for a total of $43.75. An AMSOIL synthetic nanofiber technology oil filter will cost about $16.00 (price varies depending on the vehicle - I picked one of the higher priced filters).

So, 5 Quarts of ASL 5W-30 = $43.75 1 AMSOIL Oil Filter = $16.00

The total for parts is $59.75 plus applicable sales tax. There is still labor to install the oil and filter. That will probably be $12.00 to $15.00. Total for parts and labor = $74.75. There are only 5 quarts of waste oil to recycle.

Compared to lowest price above of $159.60, that is a savings of $84.85 plus you only have to take the vehicle once to an oil change facility and ask them to install your oil and filter.

Labor pricing will vary depending on the state and locality.

AMSOIL - Offers the absolute best in lubrication and wear protection AMSOIL - Is the only lubrication company to offer a guarantee - In Writing AMSOIL - Is more effective at dissipating heat and will lower crankcase temperature by as much as 50 degrees AMSOIL - Reduces friction thereby increasing fuel economy AMSOIL - Resists high temperature breakdown that forms sludge and varnish AMSOIL - Offers the lowest temperature fluidity thereby facilitating cold weather cranking AMSOIL - Reduces Oil Consumption and Emissions (see chart on linked page)

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The AMSOIL Guarantee:
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The above information is offered as information for any who are interested. I apologize in advance for the lengthy post and will attempt to keep future communications at one viewing page or less.

Thank you for your time and patience.

Reply to
Steve

OK so after I have had this truck 12 years, it's had at least 4 different thermostats, two by me and two more by two other mechanics fixing the heating problems along with a water pump and an intake manifold gasket, I decided to take it 9 (the thermostat) out all together and the truck runs 150-160 on a 90 degree day towing a 3000 pond load. What is up? Is it possible all four thermostat have such poor flow they can not pass enough coolant to keep the engine cool. If that is the case where can i buy the best thermostat made for this engine? Try it and see if the temp will stay in a reasonable range. I think 150 is probably cooler than I should run and now it actually runs cooler than that when the OA temp is around 50-60 in the morning.

Reply to
mlemke

What about the possibility of a burr on the inside of the thermostat housing, causing it not to open fully when needed?? I presume you've replaced hoses several times in diagnosing this, but a hose collapsing could do it also.

Reply to
Miller

About the best are the Stant Superstats and the Robertshaw High Flow units. The later opens fully and provides no restriction once fully opened. And they do make a 195 degree piece for that engine.

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The service bulletin I have on that truck also says that 225 is not an odd temperature for it. I assume that you have verified that the gauge is correct? I have seen a bunch of them that are not even close.

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should take you to the service bulletin. Itruns you through a bunch of tests and a couple modifications that can bemade to the water pump to increase flow.

Reply to
Steve W.

Good one about the hose. I did get a hose once that did not have the spring inside it. Something with the manufacturing. Had to go to a different parts store to get the correct hose.

Reply to
Bill

The thermstats I've seen, they do restrict the flow of coolant. Very possible it's not enough to keep up with the heat load. I wonder if a lower temp stat would be useful. Then, it would open sooner.

Reply to
Stormin Mormon

Check the catalytic converter. Sounds like it could be time for a new one.

Reply to
Tim

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