Well it even does this on highway speeds. And it's not something like it stops at a certain point it just gets hotter and hotter untill I have to shut her off. A friend mentioned a head gasket. You guys think thats a good possibility?

 

It could be several things. I'm still unclear if it ever ran properly and correctly in your ownership. It sounds like it was perfectly fine before you replaced the working fan with a too small electric unit, and now you're chasing a problem that doesn't exist, spending hundreds of dollars on replacing perfectly good working parts.

 

Head gasket...let's look at the possibilities for failure:
1. water passage leak to cylinder...steam in the exhaust and noticeable loss of coolant. Loss of compression to affected cylinder, rough idle
2. water passage leak to outside engine...steam and hissing at the point of failure
3. water passage leak to oil galley/oil return passage...loss of coolant and oil that looks like a chocolate milk shake

From what I have read so far I wouldn't think that you have a head gasket issue. As 52Merc has said, shotgunning the problem is not the best way to go. If you can't establish when the engine ran at the proper temp then it will be difficult to determine why it no longer does so. I am sure that there are many on this forum who, given that they could inspect this truck in person, could find the problem in short order...but as it stands, everything put forward so far is conjecture. It might be time to take it to a reputable shop and have the problem diagnosed professionally.

 

Thanks for your help but I have put 80 dollars into it so far so I wouldn't consider it hundreds. Actually adding the 16 inch fan has allowed it to overheat alot slower then before. And yes I am not trying to jump ahead but you guys say to take her to a professional and I did. He said we will need to look at gasket. Today I decided to start her up and I could tell there was a rough idle. Nothing to major though. I'm doing what you guys said and am changing the thermostat to a 180 instead of the 160 the autozone guy said was for my truck. At nighttime it runs alot cooler obviously. I appreciate all of you that are being very kind and helping me out. I understand I am not a guru like the rest of you guys so I appreciate those of you who are being patient with me

 

If the PO installed the head gaskets incorrectly this is exactly what can happen. Assuming this problem did NOT exist prior to your ownership, this wouldn't be the problem. I'd contact the PO and ask if this overheating has been a constant problem, and how severe the overheating was. Ford head gaskets are designed to fit only one way but can be installed backward if you can't read the word 'front'. (Usually an illiterate chevy guy doing the assembly ) (May also find this guy putting the main thrust bearing on the #5 cap... )

Another thing like someone mentioned could be that the lower hose is sucking shut. Easy to check that. Just stare at the lower hose and revv up the engine to 2000-3000 rpm. That hose should stay round as can be.

Also- you said you can reverse your electric fan? I can too on mine however, in order to do so you have (in my fan's case) to remove the blade from the motor and flip it over. Then you can now reverse the motor. Now yours may be different, but is something to check.

Shouldn't have to pull the rad hose off to see if the waterpump is working. Just leave the radiator cap off and watch to see if the coolant is circulating. DO NOT take it off after it's already hot. Start it cold and let it run, warming up, and watch for coolant movement. Can also tell when the t-stat is opening by this method too. If it's working, that water should be flying by the radiator cap opening when the t-stat is open.


One more thing to add... How are the waterpump bypass hose and heater hoses hooked up? I ran into an instance once where these were all hooked up backwards on a rig and it caused the pump to cavitate. Be sure to use the proper pre-formed bypass hose for the smblock ford. A straight section of hose will normally kind and do you no good. Just something to check aswell.

 

Thank you so much for your nice imput. I will defiantly look into the heater hose setup to make sure that is all going good. So tonight I found out that the kid at autozone sold me the wrong rad cap and thermostat. I told him all the info on my truck and he gave me a 160 thermostat and a 16 lb rad cap! I asked him to make sure it was the right lb cap and he said he is sure. I looked up the number tonight and found out it wa the correct lb for my radiator. I checke the cap before I bought it and there was no lb reading. Took the cap back ad the guy said he was sorry and gave me my money back for the right cap. Was this bad to run it for a couple days with a 16 lb cap? So that could be a problem.

 

The cap? No. Wouldn't cause any overheating issues per say... at least not like what you're having. It just wouldn't vent out the overheated coolant (pressures of the system) at the proper pressure. Worst case scenario you'd blow a core in the radiator or something else in the system. However, 16 lbs is not really uncommon on older cars. Now if you put that on a new car with plastic or an aluminum radiator... you could do some damage there. The older copper core radiators will take a pretty good beating tho. As for the T-stat... 160.. 180... doesn't matter because if your truck's at 200 or more that thing is wide open either way. NOW- I have been noticing that these chinese and taiwan t-stats seem to come with smaller and smaller openings every time i buy one. You could have flow issues if the t-stat opening is not large enough. This may be an area of concern, but I have my doubts. There are supposed 'high flow' thermostats available via the aftermarket. i just don't think this is your issue, but there stands a possibility.

Do you have stock-type pullies or aftermarket (possibly underdrive?) pullies on this thing? Sometimes improper pulley matches cause the waterpump to not circulate the water fast enough (or even too fast). Ford is bad with their monotonous array of pulleys and if you're not familiar with their match up you could have problems there too.

Sorry not trying to scare the crap outta you.... just trying to think of all the possibilities that are ususally easy to rule out that are sometimes overlooked.

 

Hey guys I've got good news! I went ahead and changed my tstat again!!! And my truck will run at about 220-230 and stop there! So it doesn't continue to get hotter and hotter anymore. But now I need to figure out how to get her to run a little cooler cause that's too hot. What should a 302 run at in about 115 degree weather? Anyone know? At night time I run about 205.

 

Hey that is good news! Maybe that new fan isn't getting it done - or add a shroud - you & I both live in pretty hot places - might need a little heavier duty fan than these northern trucks.

Ben in Austin

 

I am going to throw a few things to additionally check (I am sure you are tired of checking things):

Question #1: What do your spark plugs look like (white, tan, brown, etc...)?

I ask this question because if you are running lean, you will run hot. If your plugs are white, you will need to richen up the carb. If your plugs look tan, your carb is probably set up fine.


Question #2: Someone earlier mentioned your timing. What intial timing are you running? if you are running too much advance, you will run hot.

Question #3: Where did you hook up your distributor vaccum advance hose? Did you hook it to manifold or port vacuum source? If you hooked your vaccum line to a port source you might try a manifold source. Hooking a distributor vacuum advance hose was a 1970's emissions control approach which caused engines to run much warmer. There are many articles on this topic. Hot rodders have claimed to run cooler and gained better fuel economy by switching to mainfold vacuum source.


I look forward to reading your replies.

Lance

 

I might also question the accuracy of your gauge. If you have another one handy, I'd try changing that, just to see.

 

Question #3 contradicts Question #2. The second you hook up your vacuum advance to manifold vacuum, you'll be at full vacuum advance at idle, overriding your initial timing setting. Ported vacuum is the only way to go, especially with Ford applications. Some GM cars use manifold, but Fords do not, unless they are running full smog equipment (70s stuff), then that is where the dual diaphram distributors come into play. Leave it on ported vacuum or disconnect completely (and plug both nipples).

 

I knew the ported/manifold vacuum statement was going to ruffle a few feathers as this is a very misunderstood concept.

Ask Truxx1956 about the carb mods I did this summer at the GSM F100 Run. He gained 5 mpgs by me adjusting his step up springs (Edelbrock 1406) and moving his vacuum line from port to manifold.

https://www.ford-trucks.com/forums/1...00-run-12.html


By connecting your distributor vacuum line to manifold vacuum you pull vacuum at idle which advances your timing. At idle, you are at a very lean condition. By advancing one's timing at idle, this provides adequate time to burn the fuel during this lean condition (lean condition = more time need to burn fuel). The benefits of using manifold vacuum are cooler running temperatures and better mpgs. I am over simplyfying this confusing concept, but one can read a better detailed description in the following site which does a pretty good job of explaining this (post #19 from C9):

Ported or manifold vacuum? - THE H.A.M.B.

I am not going to get into a pissing contest over this issue. This is a suggestion which the OP can try or not. If fordman doesn't want to try my suggest that is ok.

Lance

 

X2.


Or get a manual thermometer to stick in the top of the radiator as it heats up so you can compare it's reading with the one in your truck. I was going to suggest the wife's meat thermometer or candy thermometer, but since anti-freeze is poisonous, I'm not sure you'd ever want to use it for food again. If she happens to read this, my name is Arrowhead Fred.

 

I use one of the laser temp tools. cheap at Harbor freight and great for telling temps on all kinds of things.. (in to the rad, out from the rad. exhaust temps, ..., trailer tire temps)

Sam