Overheating

Hi Guys,

Need advice. I can drive my truck around town just fine. On the freeway for 15 minutes leads to overheating. Truck is recently new to me. Coolant was brown. Flushed and flushed until water ran clear, then filled with new coolant.

Parts I've replaced trying to fix overheating
1. Radiator
2. Radiator cap
3. Thermostat tried 190 then 160 then no thermostat

Not smoking when starting, some drops of water out of drivers side tailpipe. When I changed the oil I didn't notice water or coolant, but I may need to change again to check.


It was recently in the shop, where I got bent over. Had the following work done which cost me 1600..........

1. Installed 4bbl holley
2. New intake manifold
3. HEI distributor
4. Water pump (old one was leaking) Mechanic said when he removed old pump engine had been gunked up.
5. New 1wire alternator

That work was that much and took 2 1/2 weeks to be done. All at a mechanic I've been going to for some time and thought I knew and trusted not to do me dirty. I got it back with a "I'd drive it anywhere! It's totally reliable!" , drove home at night on the freeway, got off freeway boom coolant exploded out of reservoir. Call Mechanic "I'll stand behind my work".

After waiting 2 1/2 weeks for my truck I wasn't in a hurry to take it back. That's when I installed the new radiator and did testing with the different thermostats. I also installed an external trans cooler and trans filter to clear up the lines running to the radiator.

Now I'm about to take it back to his shop so he can stand behind his work. I'm thinking now it's a head gasket problem and that he's going to try to ring me up some more. I didn't expect a 1600 bill and can't afford another for replacing the head gasket.

I'm thinking of trying some Blue Devil and saving to have the head gasket done somewhere else. Or try to do the head gasket myself. Or buy someone's take out engine and get that installed. Or maybe the water pump is bad?

The most common cause of the condition you describe is retarded timing.  Timing needs to be set with a vacuum gauge.  Don't trust the timing marks - they may be off.  Make sure the new distributor is advancing while you're at it.  It's possible that something else could cause it, but timing is usually the culprit and it costs nothing to try the simplest fix first.  There is a good post on here if you search a little on how to set it with a gauge.

Good point. I'll have to check it. It does seem to be a little high / fast.

One thing many overlook is the raditator , most of us have still the stock units which many work still but they have 40 plus years of gunk in them

If you got coolant at the tail pipe sounds like a head gasket got a run a thermostat.Upgrade radiator?

ok lets look here - coolant out tailpipe is ok -water dripping =!! in cold weather!! =condensation from hot exhausr in cold exhaust system!! after warmed up & driven some all water from exhaust should not!! be present!! Now- new???? Radiator?? 3 or 4 row ?? or 2?? same size radiator?? electric fan added?? or old stock metal fan?? have a clutch fan?? radiator size is same or larger than stock?? Now -as last posts =id actually go to timing & recheck it!!!!!!!!!!!!!!!!!!!!!!!! driving around town is slow & if cooling good -alls ok as water flow is slow=on highway-faster & likely timing is effecting also-more fuel / rpm= more heat!!!!!!!!!! Now =you must run a thermostat- use a 180 -can use 160 yet usually that last wont slow water flow so it can be cooled as good in radiator!!!

I guess my post wasn't clear. Needing a head gasket or not if it still has the stock rad. Im sure it needs recored, even if it seams to be working now

1 from what i'm reading water at the tail pipe is this only at startup or also after it's warm.
2 the rad and cap and pump are all new, Did you back flush thru the heater hose ?? i'd try that a few more times,.
3 Was there a 4 bbl on there, is there headers on it ?? A member here Jkr pointed out to me on on my dodge they never installed a 4bbl, but i did and kept the 318 exhaust manifold, So i changed to a larger exhaust manifold, If you add more air and fuel it needs a place to exit as well,
3 do you know what rear gears are in it now ?? did the p.o. change them, Do you run a tack ??your rear gears may be to steep, The timing and the vacuum gauge are important. and 99 percent of the people who work on these old cars and trucks don't use a gauge. (OH I DON'T NEED THAT ) i'm not a Ford guy but just telling you what i am thinking, But the Ford gang will put you on the right track.

Thank you for all the help guys.

I made some progress today. When I got the truck back from the shop it overheated due to a gunked up radiator. The mechanic replaced the thermostat with a 195 degree one.

I purchased a new 2 row 1 inch core aluminum radiator from ebay. When I installed the new radiator, I bought a new thermostat too 160 degrees. Based on the thread keeping your v8 conversion cool.

Once it overheated with the new thermostat and radiator, I wrongly thought that running without a thermostat wouldn't result in overheating. Once you guys mentioned that this morning I went to install a thermostat and fresh coolant. Right before I installed the 160 degree thermostat I bought, I thought I should test both the thermostats I have. It turned out the new 160 degree failsafe thermostat had failed.

I decided to re-install the 195 degree thermostat since it did work when I tested it in boiling water. It now seems to not be over heating. For the most part the temp needle is in the middle and goes up to 3/4 of the way, then thermostat opens and it's slightly above the middle. The weather is a little chilly now though, so I'm thinking it still might be running a tad hot. I might go buy a new 160 degree thermostat, to see if it brings it down a little.

I also need to buy the vacuum gauge and light gun to try to check the timing. At the least the vacuum gauge so I can check the inches.

dix wrote:1  from what i'm reading water at the tail pipe is this only at startup or also after it's warm.
2 the rad and cap and pump are all new,  Did you back flush thru the heater hose ?? i'd try that a few more times,.
3 Was there a 4 bbl on there, is there headers on it ?? A member here Jkr  pointed out to me on on my dodge they never installed a 4bbl, but i did and kept the 318 exhaust manifold, So i changed to a larger exhaust manifold,  If you add more air and fuel it needs a place to exit as well,
3 do you know what rear gears are in it now ?? did the p.o. change them, Do you run a tack ??your rear gears may be to steep, The timing and the vacuum gauge are important.  and 99 percent of the people who work on these old cars and trucks don't use a gauge. (OH I DON'T NEED THAT ) i'm not a Ford guy but just telling you what i am thinking, But the Ford gang will put you on the right track.

1. There is just a few drops that come out when it's cold. After it's warm there is no longer and drops from the drivers side tailpipe.

2. I didn't try back flushing through the heater hose. When I installed the new radiator, I would fill it with water, run it for about 2 minutes, then drain. I repeated this until the water was clear. I then replaced the water with coolant. I might try buying a flushing product and flush the engine out, since the water was pretty brown at first.

3. No headers. I went from a 2bbl to a 4bbl. Stock intake manifold to a weiand manifold. I was trying to see if I had room for some shorty headers and maybe a wider pipe, but wanted to get the overheating done first.

4. The gearing is 3:00. When it was up on the lift I had the mechanic check by spinning the driveshaft and watching the wheels rotate. I'm thinking there is a vacuum issue as well. I think I hear a whistle from time to time.

Twinpilot001 wrote:ok lets look here - coolant out tailpipe is ok -water dripping =!! in cold weather!! =condensation from hot exhausr in cold exhaust system!! after warmed up & driven some all water from exhaust should not!! be present!! Now- new???? Radiator?? 3 or 4 row ?? or 2?? same size radiator?? electric fan added?? or old stock metal fan??  have a clutch fan?? radiator size is same or larger than stock??  Now -as last posts =id actually go to timing & recheck it!!!!!!!!!!!!!!!!!!!!!!!! driving around town is slow & if cooling good -alls ok as water flow is slow=on highway-faster & likely  timing is effecting also-more fuel / rpm= more heat!!!!!!!!!! Now =you must run a thermostat- use a 180 -can use 160 yet usually  that last wont slow water flow so it can be cooled  as good in radiator!!!

I need to change the fans from the stock metal clutch fan, to some nice electric ones. I wasn't sure how much space I was going to have with the new radiator. I thought I was going to mount the external AT cooler up front, but it went in the rear instead, leaves a good amount of space for fans in the front.

Hey Guys, Could you watch this video of the start up and idle. I hooked up the vacuum pressure test guage and filmed it. The mechanic said when he was working on it, it looked like someone grinding the timing mark off the engine. He said he did find TDC and confirmed it with a light and something else resulting in 12 degrees advanced I believe.

The previous owner did modify the engine. I was told it was overbored .30. I can't confirm what cam is in there either. lol

Video
https://www.youtube.com/watch?v=r7dpaHVFYtQ&feature=youtu.be

Eco watch this video.
https://www.youtube.com/watch?v=X0uEMeDVxaA

The drips from the exhaust are just condensation. When you burn gas in an internal combustion engine, the by-products are, carbon monoxide, and water. after the engine warms up, the exhaust heat will evaporate the water, and you wont see it. If you are not sure of your timing marks, just time it like in the video. Get your highest vacuum reading, then back it down about 2 lbs. Get the air fuel mix right and the engine shouldnt run hot. Now you said nit runs ncool at slow speeds, but overheats at high speeds. I have been fighting this same problem for a while. I dont have the stock belly-pan. I built my own belly-pan, and also made the dogbox wider so that fresh cool air can come in through the radiator and have plenty of room to excape out the back of the dogbox. Until now, the hot air was recirculating back through the radiator at speed. With a v-8 there isnt enough room for the hot air to get out the back. Some people cut the back out of the dogbox and vent it throught the front of the bed (in pick-ups). If yours is a van, you can make the rear of the dogbox go back further, or make it wider by the valve covers. Hope this helps.

Thanks guys. She's running much better after the thermostat fix and carb tuning. I'm buying a tach gauge so I can make sure my curb side idle isn't too high, engine was smoothest with it slightly higher. Once the tach is here, I'll try to tune the carb again to see if I can get it a solid needle. No matter what seem to get a slightly shaky needle.

Holley has some good videos too.

1. Float
https://www.youtube.com/watch?v=ge-mIk6nEYQ

2. Idle Curb Speed
https://www.youtube.com/watch?v=_QM0L9b4Q5s

3.Idle Air Mixture
https://www.youtube.com/watch?v=UPGLUsW5ZeE