The impossible to solve overheating problem

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inertia said:
Zactly !

And I "agreed" with MOPAROFFICIAL because his common sense is the same as mine.

That OK with you furyus2 ? ? ?
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Wow. Sounds like you have some aggression issues. Since the object is to help the OP, and you feel one of my comments was incorrect, it would have been polite of you to post your opinion to be of service to the OP.
I could be wrong, I've been wrong in the past, but asking you why you thought I was wrong was fair.
 
I might have got a time for a garage to check if there are high levels of co2 in the coolant tomorrow. Unfortunately the garage that could pressure test the system dont have another time for a few weeks.
Also test started the car today and immediately inspected the exhaust very closely and Im not sure if Im imagining it but it looked slightly white, when I held my hands at the tailpipes they became a tiny bit damp, I wouldn't say it was obvious in either case but still.

Anyway, will try to get the coolant checked for co2 if possible tomorrow then do some of the tests like checking the system for flow, heater core, flushing it etc. and see where I end up.
 
Just stick your nose in the radiator-cap opening and you'll know rightaway if there are exhaust fumes there.
You could also buy a CO2 homesafety device for restricted chimneys and such. Put it in a plastic and hold the bag over the radiator opening tightly.
 
You can buy a block test kit at most parts stores. Blue chemical in a tube inverted into the radiator. Don’t suck up any coolant. If the chemical changes color from blue to green or yellow you have hydrocarbons in your cooling system. Takes about 5 to 10 minutes
 
Just back from the garage, I had the original radiator installed and we put a Co2 meter at the opening to the radiator, no sign of Co2 at all. The guy was nice and didn't charge me for the 15 minutes.
I also did BigBlockMopars test before this smelled for exhaust, could not smell anything either. So I think it's safe to say my theory of combustion in the coolant is gone. The guy at the garage said that if I'm losing coolant into the cylinders it's would be very obvious ammounts of white smoke and that the engine might run bad on cold start up.
Going to start trying everything that has been suggested later on today.
 
purplehazenils said:
Just back from the garage, I had the original radiator installed and we put a Co2 meter at the opening to the radiator, no sign of Co2 at all. The guy was nice and didn't charge me for the 15 minutes.
I also did BigBlockMopars test before this smelled for exhaust, could not smell anything either. So I think it's safe to say my theory of combustion in the coolant is gone. The guy at the garage said that if I'm losing coolant into the cylinders it's would be very obvious ammounts of white smoke and that the engine might run bad on cold start up.
Going to start trying everything that has been suggested later on today.
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Just been reading this post, I had an overheating problem on my 62 S series slant, it wouldn’t boil but kept getting hot at lights and heavy traffic. Pretty much went down the same path as most of the posts, in the end, a new radiator, reinstalled spring in the bottom hose, put a seven blade fan from an ac slant on, made a fan shroud, made sure fan blade was half in half out of shroud and put a new original style impeller water pump on. I tested system with a thermal camera, bonnet shut and at idle in the garage, temps are now 71 C inlet temp, 44 C at radiator outlet. I can vouch for all the previous post, 1 step at time, good luck with sorting it, sorry we use Celsius for temp in Australia
 
I bought the test kit for testing for combustion gases in coolant. Works very well.
Glad its been ruled out.
 
Treblig said:
Also you'll need the radiator support to hood seal to keep engine heat from recirculating to the front of the radiator.
treblig
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This is one of the more important parts of the cooling system that everyone ignores.

purplehazenils said:
a tiny bit more air from a radiator support to hood seal probably wont solve it all..
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There is WAY more then a "Tiny bit" of air that gets pulled "back" thru the radiator.

The main purpose of the hood to core support seal is not to force more air through the radiator.

It is to keep the hot engine bay air from being pulled back over the top of the core support and recirculated through the radiator over and over and over continually adding heat to the cooling system.

Do a search on my username and look at my post on my cooling problems. After all I went through the hood to core support seal was what cured I would say 90% + of the overheat.

The other major improvement was getting the proper crank and water pump pulley sizes.

You say it overheats setting still or holding a steady speed. Mine car did the same thing until I put the seal in place.

I am not saying this will fix Your problem, but it is an easy and inexpensive solution to try.

Herb
 
I tested the water pump using the suggested test, it could empty the radiator and run out of water in a few seconds so it works pretty well. I then flushed the cooling system using a product from STP, the water coming out after was really clean but its not that surprising after having emptied and replaced coolant about 5+ times in the last couple of weeks. In the end I didnt dare use the citric acid as someone warned me about acids with the aluminium radiator.

I did a test run after this starting from cold driving at a constant 40 mph. The car overheated but it took longer than before.

Then I sealed off around the radiator, not sure how you guys do it but I used some foam and tape lying around
Did another test run at 40 mph starting with a warm engine and it overheated again but I think it takes slightly longer than it did before.

Will write update after some more tests.


EDIT:
I also bypasses the heater core, forgot to mention that,

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After the second test when I shut the the car down at 110 Celsius or 230 Fahrenheit I did notice that there was a slight noise coming from the cap on the overflow tank. Judging by how hard the hoses become it seems like there is significant pressure but maybe a small leak here could be problematic?
 
purplehazenils said:
After the second test when I shut the the car down at 110 Celsius or 230 Fahrenheit I did notice that there was a slight noise coming from the cap on the overflow tank. Judging by how hard the hoses become it seems like there is significant pressure but maybe a small leak here could be problematic?
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If there is any leak in the system (pressure or water) the car will get too hot. It's the pressure that helps keep the water from boiling.
 
looking at your pics it appears only about a 1/3 of your rad is working ,you need a full shroud behind the radiator ! that electric fan wont cool a lawnmower
 
Treblig said:
If there is any leak in the system (pressure or water) the car will get too hot. It's the pressure that helps keep the water from boiling.
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Yeah then a small noise/leak there is not good, Im going to put a spacer or gasket in the bottom of the "well" for the overflow cap make sure its tight and see what happens.
 
teringer said:
looking at your pics it appears only about a 1/3 of your rad is working ,you need a full shroud behind the radiator ! that electric fan wont cool a lawnmower
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Yeah its not the best fan or setup, however the only driving Im doing for the moment is at 40-45 mph.
 
purplehazenils said:
I am about to give up and put the car in long term storage, I have an overheating problem which came out of nowhere and it seems like I cant affect it at all. I only have one more trick up my sleeve. Tomorrow I will be booking the car into a garage that is going to take samples of the coolant and determine if there are high levels of co2 in it (ie. leaking head gasket or a crack in the block/head)

------The engine:------
¤ Motor: Chrysler Smallblock 360ci - 5.9L
¤ Heads: 915J machined to 56.8 CC Std 1.88 / 1.60 valves, compression 9,8:1
¤ Cam: CompCams Xtreme Energy XE262
¤ Carb: Carter ThermoQuad
¤ Intake: Edelbrock aluminiumintake
¤ Ignition: Mallory
¤ Transmission: Torqueflite 727
¤ Exhaust: Doug`s long tube headers, 2.5"system

-----The cooling system:-----
¤ Radiator: Big *** aftermarket aluminum one (think its actually for a 96 ford mustang) so big that I had to widen the frame a little to make it fit
¤ Overflow tank: Nissan s14
¤ Fan: Not sure what size, pretty big anyway

-----The problem:-----
¤ The car overheats while standing still or moving at a constant speed for example 45mph
¤ It takes under 10 minutes of driving at constant 45mph to get to 220 Fahrenheit
¤ If the car stands idling it gets to 220 from a cold engine pretty quickly too
¤ If you keep driving or idling it will just keep rising from 220

-----When the problem started:-----
¤ The car came with the original cooling system (4 years ago now) and would overheat once in a blue moon I dont know why.
¤ I upgraded the cooling system (2 years ago) and it never overheated, well, it did a few times but I had the timing to lean

¤ The car has stood still two years with the engine out while I did suspension upgrades. After putting in all back together the car now has a massive overheating problem. The following was done to the engine when out:
1. Changed some freeze plugs
2. Re tapped the manifold bolt hole which goes into the cooling system (front right farthest from driver)
3. Re built the carburetor (it is tuned well, not running too rich/lean)

-----What I have tried doing already:-----
¤ Run with/without thermostat, have even tried with various restrictions to flow
¤ Checked that the lower radiator hose does not collapse stopping flow
¤ Tried putting ignition to very rich-lean and everywhere inbetween
¤ Checked that the temperature gauge is not off with an I.R thermometer
¤ Tightened all the hose clamps for the cooling system
¤ Taken apart the cooling system checked if hoses were ok
¤ Checked the water pump (it was totally fine)
¤ Checked that the radiator is not clogged
¤ Replaced the cooling system with the original cooling system, radiator etc. (same result)
¤ FYI The engine has been flushed a couple of years ago
¤ Compression tested the engine biggest difference between two was 11.2 Bar and 10.3 Bar



Does anybody have any theories? If there is no co2 in the coolant and if maybe changing spark plugs doesnt make a difference I will be giving up and parking the car for the next few years, which kinda sucks after spending so much time and money.

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It looks like your fan is on back the front,the inside curve of the blade should face the engine.
 
Your description of overheating both sitting still and driving.. I ran the gambit with an overheating prob with my 340. Replaced the thermostat, flushed the engine and radiator and heater core, replaced the radiator, and finally replaced the fan clutch and then the pump. It was the pump that was the culprit. I've read several articles the the fins in the original pump do not have a shroud and that the fluid cavitates within the housing, so I replaced the pump that has the shroud, From Rock Auto, GMB 1201070P High Performance pump. Walla, running at normal temps.

This info can be found elsewhere in FABO.
 
I have ordered a new pump, fixing the small sound coming from the radiator cap at 230 Fahrenheit didnt lead anywhere..
Am still doubting that it is the pump, but my dad is 100% sure it is so we have a bet where if it is the pump I pay for it and if it is not he pays for it. Pretty good deal I must say! :)
 
the cap only comes into play when it hits 100 C or 212 F . the water pump test u did shows u do not need a pump. the tiny fan and shroud is the problem
 
Hello. Read through this thread twice and while there have been a number of great suggestions, I thought a little different approach may help. Keeping in mind this is not a criticism towards you or any other members posts, a Flow Chart/ Diagnostic Tree mindset may get you closer to resolving this problem. Please forgive the length of this post as it may get a little wordy.

First, in the 5th paragraph of your original post you said, "The car came with the original cooling system (4 yrs ago now) and would overheat once in a blue moon I don't know why "......STOP......

This tells us there's been an intermittent overheating problem from the start and brings up some questions:
A) What's your definition of "once in a blue moon "? For instance, if you only drove the car once or twice a month for 4 months a yr and it overheated 2 or 3 times in that period, that could mean a problem 25% of the time, or possibly more. This could be significant.
B) You then said, "I upgraded the cooling system (2 yrs ago) and it never overheated, well, it did a few times but I had the timing too lean".....STOP.....This tells us there was STILL a problem after the upgrade. Setting aside the "timing too lean" part, this is important because in the next paragraph you talk about the car sitting for 2 years after pulling the engine. If you did the upgrade 2 yrs ago and pulled the engine 2 yrs ago, did you drive the car enough between those two events to really diagnose whether or not the original problem was solved ?
C) In the second paragraph you give a description of the engine. Is this the EXACT engine you started with from the previous owner? Was it upgraded over the first 2 yrs? Or aside from the 3 changes you listed in paragraph 6, were the upgrades done after the engine was pulled?
D) In paragraph 6 the problem,( after the engine R&R and sitting 2 yrs) became in your words, "massive". Other than the 3 things listed, were any other changes made to the engine/cooling system?
This is just a starting point depending on your answers to the above questions. Be HONEST w/ yourself when answering. Using the Flow Chart mindset, you may need to backup, flip on your memory banks, and see the car as it was ORIGINALLY. Then, identify which parts/conditions are still part of the systems and look at those FIRST. If you don't use a systematic approach to diagnosing the problem....you're GUESSING, and the more you change, the more difficult finding the underlying problem becomes. Diagnosing "with the Force", in most cases, will do nothing but increase your frustration/aggravation level and lighten your wallet.
I know I haven't given you any specific answers, but hopefully this will start you down a different avenue because the one you're on now doesn't seem to be working. Good luck and chin up, you'll figure it out. Cheers

P.S. On a personal note, sooner than later, you need to take the car to someone who has a professional coolant flush unit and get that crap completely out of the ENTIRE system if it hasn't plugged up part of the engine/radiator/heater core already. Just sayin.
 
the rad hose off test isnt really the best test.
Depending how you were adding water to the system the flow from the hose would taint the results.

If it overheats again, place your and over engine in front of carb to feel the wind blowing through rad. Firstly, it better be a good draft and it better be hot.

Friend with his chevy dropped by yesterday, looking for a vacuum advance. His one year old chinesium one quit,i had a working 40 year old one. It started overheating. Vac advance repair cured it.
 
fwiw - simple shroud sure helped the Slant (with correct pressure cap and original factory thermostat)

Also, get it warmed up to right before you think it's overheating, removed the cap slowly, check the actual temp of the coolant using a baking thermometer (grocery store item).

Good luck!
lancer shroud1.jpg
 
90% of these "overheating" posts have one thing in common. A small electric fan such as yours, which is totally inadequate
 
Unless I missed it, he continues to avoid measuring rad in/out temps, or shot the rad looking for cold areas, which would decisively eliminate the engine. He's ignores the fan issue. He Has All the info he needs, he just needs to act.. jmo
 
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