Overheating crisis

[kcederwall08]

Hey guys,

I'm having a little bit of trouble keeping my 438 stroker motor cool. It has always ran a little hot, but just recently after changing a few things the engine started running too warm for my likings. The temp seems to sit a bit above half way in the "safe zone" when moving, but in traffic, it goes higher, sometimes reaching the 230 mark.

The things I changed were really simple, and since then i have but all those changes back to normal. It started with my heater core leaking, so I looped off my heater hoses as a temporary fix. Then I shortly after changed the temp sensor, and a section of wire because my gauge kept dying. That solved the gauge issue, but it started running hotter. I then installed a 180 degree high flow thermostat, and it ran even hotter. , so i've changed almost all of that stuff back, and it was still too hot, so replaced my stock fan with an electric fan, and it still runs hot.

I'm thinking there is an underlying issue that I'm missing, probably with the timing or fuel. I noticed today that it smells like it is running very rich, and it burns your eyes, but doesnt running lean usually cause more heat?

I also had the car checked out by a local shop, and the gauge is reading correctly

Any Ideas?

[craig]

the heater core actually should be left in the circuit...this adds about a quart or more of coolant, and gives another place for your system to lose heat and cool off...

[b5blue]

Back when I was fighting with timing issues from a crappy re-man dist. I found timing can do just what you describe. It would climb to 230+ anytime I got stuck in traffic and generally ran hotter overall.

[firefighter3931]

Where is your timing set ? retarded ignition will create a lot of heat. What is the CFM rating on your electric fan ? Unless it's pushing 3000 cfm it won't be enough. I just went through this on my own car. I also had a hi flow 160* stat and swapped in a 180* standard flow unit and noticed it runs cooler....i found that interesting. 

First thing i would do is check the timing and see what you've got. You should have at least 14-16* of spark lead at idle.



Ron

[kcederwall08]

Thanks for the replies guys.

I'm not sure what the timing is set at, I've have to pick up some timing tape this weekend and do this.

The fan I got was a 2,500 cfm, and I was a little worried that it wouldn't be quite enough, but I don't have much space to fit a bigger fan. The one I have is a flex-a-lite 16" that is 3 1/2" deep, and it has to be offset so it doesn't hit the water pump nose. So I could probably fit a bigger fan, as long as the blade part is thinner than the motor part.

This is the fan: http://www.jegs.com/p/Flex-a-lite/Flex-a-lite-LowBoy-Hi-Performance-Trimline-16-Electric-Fans/759937/10002/-1

I will post up some pictures of the fan fitment when i get a chance.

I figure the reason that the high flow thermostat makes it run hotter is because the water is flowing through the rad faster, not allowing the coolant to be cooled as much.

[kcederwall08]

Pictures of fitment:

[kcederwall08]

Okay, so today I checked the timing, and according to the stock timing chain cover timing marks, I set the timing to about 14*, it was at about 7* or so. I took it out for a quick drive, and it did fine for a little while, but it slowly got hotter, and when I went into traffic it got pretty hot (215 or so). I took it on the freeway to try and cool it down, and it heated up even more, and when i got off the freeway it maxed out the temp gauge to 250. 

The car felt like it had better response and power with the timing, but it ran much hotter.

I already have upgraded the stock 22" rad to 4 cores, and put on an aluminum high flow water pump, so I really don't know what else I can do.

[b5blue]

Dang! For a moment I thought it was good news. (it's running better, but hot?) 

[oldrock]

I have no experience with charger engines overheating but with other overheating probs, we sometimes had some good luck changing the plugs to a cooler burning range spark plug.

[Purple440]

I had an overheating problem on my 440 and advancing the timing helped.  Also, I was running lean on the carb.  I hit 230 once, but after those changes I never did again.

- Doug

[b5blue]

I was thinking lean can do it too...but odd how it was OK then went bad. 

[kcederwall08]

Okay, I set the timing for a little more advance, around 16* or more and tried to adjust the idle mixture, and it ran a little worse. It seemed to stutter a bit, and didnt run any cooler. I took it out for about a 15 minute drive, and it started out cool, and slowly rose up to 230+ degrees by the time I shut it off. Then I let the fan run to cool it down a bit while the car was off, and it drained my battery. After that I had to wait in the heat to get a jumpstart and drive it home. Not a real fun day....

I'm thinking that the carb is running a little bit lean with the jetting (I know nothing about jetting btw, so I'm just guessing), and also the fan isn't quite strong enough to cool the motor down at Idle. The carb is a 750 edelbrock, which I know isn't the greatest carb, but it should at least be able to work. The car cant even seem to keep cool while moving like it could with my stock fan.

This is getting very frustrating...... 

[mjwebb]

water pump not making any noise is it?

[b5blue]

OK lets break it down you changed to a electric fan to fix this and it didn't (?) if I read your opening statement (paraphrased) correctly. You verified gauge function....what about accuracy? (When you read hot is it acting hot?) Have you checked for restriction of flow, I.E. open up radiator cap and watch flow, impeller on pump failure or clogged radiator? Verify timing and advance function/settings as correct. Check carburetor for proper settings and function. You sure the fan is pulling air back through radiator not blowing it forward right, (I know sounds dumb but....).       

[Blown70]

Ok, personally, I dont see a shroud... left open like that will not allow flow through that area of the radiator.  Sorry but seen this personally.

EVEN if you just run the fan build a shroud for it.....

you are not using your full radiator for cooling just a very small portion......

Tom.

[lisiecki1]

with the electric fan attached flush to the radiator a fan shroud isn't going to help    Also, with the fan mounted that way you have a very small area of the radiator that is actually being cooled by the fan......you may get better results if you offset another fan on the other side of the radiator as a pusher, effectively increasing the surface area of the radiator being cooled....

i think i would try getting rid of the high flow t-stat and going to a standard flow unit also.  How old is the water pump?  Maybe it has a vane problem?  Did you have your block professionally cleaned?  Maybe there's some blockage in the water passage.

if worse comes to worse you could always go aluminum....they tend to cool better because they dissipate heat faster..

Randy

[Blown70]

with the electric fan attached flush to the radiator a fan shroud isn't going to help    Also, with the fan mounted that way you have a very small area of the radiator that is actually being cooled by the fan......you may get better results if you offset another fan on the other side of the radiator as a pusher, effectively increasing the surface area of the radiator being cooled....

i think i would try getting rid of the high flow t-stat and going to a standard flow unit also.  How old is the water pump?  Maybe it has a vane problem?  Did you have your block professionally cleaned?  Maybe there's some blockage in the water passage.

if worse comes to worse you could always go aluminum....they tend to cool better because they dissipate heat faster..

Randy

Well at least we both agree a lot of the radiatior is not being used to cool.  I dont agree with no shroud.... sorry you have your opinion I have mine.  I have my expericences  and will stick with that in my post.

I would at least get another fan at mimimum.

[lisiecki1]

with the electric fan attached flush to the radiator a fan shroud isn't going to help    Also, with the fan mounted that way you have a very small area of the radiator that is actually being cooled by the fan......you may get better results if you offset another fan on the other side of the radiator as a pusher, effectively increasing the surface area of the radiator being cooled....

i think i would try getting rid of the high flow t-stat and going to a standard flow unit also.  How old is the water pump?  Maybe it has a vane problem?  Did you have your block professionally cleaned?  Maybe there's some blockage in the water passage.

if worse comes to worse you could always go aluminum....they tend to cool better because they dissipate heat faster..

Randy

Well at least we both agree a lot of the radiatior is not being used to cool.  I dont agree with no shroud.... sorry you have your opinion I have mine.  I have my expericences  and will stick with that in my post.

I would at least get another fan at mimimum.

i was basing that on the fact that it's mounted flush to the radiator so it is acting as it's own shroud for the little bit of surface area it is covering, a full shroud would make a difference if the fan was moved away from the radiator and attached to the shroud itself in a sense creating a vacuum in the inside of the new shroud.....I believe we're on the same page though.  The only problem with that is that it doesn't look like he has enough room for a shroud with a fan attached to the back of it....it's possible with a one-off custom piece that would offset the fan a little more than it is though.

[kcederwall08]

Okay,

The water pump isn't making any noises out of the ordinary, and it is a new "high flow" one from 440source.

The gauge reads correctly and the car doesn't run well when the gauge shows hot, especially if you get on the gas a bit, it will dump black smoke, and sputter or miss. I haven't checked for restricted flow, but I have tried to bleed the system of air pockets, and nothing noticeable came up. The rad should be good, considering it was re-cored just a few months ago, but it is possible that it isn't performing properly. And yes the fan is flowing the correct way. The block was hot tanked when it was rebuilt about a year+ ago, and the machinists didn't say anything about out, so it should be fine. The t-stat has already been replaced to a standard flow one by the way.

HOW EVER: I took the car to a shop a couple months back, and they said there was abnormally high amounts of exhaust parts per million in the coolant, and they had the heads inspected. They couldn't find anything in the heads, so they suspect that there is a hairline crack in the block. They ran some stuff through the system to try to seal it up, and it helped. The car never had or has had any smoke from the exhaust, and it doesn't really burn a whole lot of coolant. I'm really hoping that this "hairline" crack didn't get any bigger, because that may be why it all of a sudden after these few changes it started running abnormally hot. 

I really agree with you guys about the fan not covering enough of the radiator, and I also think the the cfm's aren't quite high enough for my motor. I'm thinking about going back to the stock fan, buy a new shroud, and put a small pusher fan on the front for extra flow in traffic.

[Moparman01]

Wow bud, i am goin thru EXACTLY the same thing right now, have been for 2 years now and still have not figured out my over-heating issue. I can start the car, let it idle in the driveway all day long and it won't go past 170* and guages (i have 2 of them). But, put it in gear and head down the road and temp steadily rises while driving, farther i go...hotter it gets! I've pulled into shows with the guages at 230* before. I've tried damn near everything too, still no luck. I have re-cored 26 3-core readiator, spent $300 haveing it rebuilt, i really don't want to shell more money for an aluminum rad. but i'm runnin out of things to change. I with ya man, i'm  bangin my head against a wall too, it's very frustrating!

[lisiecki1]

i think i would invest a couple dollars into a top end gasket set and pull those heads, definately sounds like you have a leak somewhere........if you pull the radiator cap and start the engine does it spew coolant all over the place after it gets to operating temp.?  also, if you want to spend the money, I bought a head gasket leak detector off a snap-on truck a number of years ago that hasn't steered me wrong yet.......it comes with a bottle of blue liquid that you put into a two stage oversized turkey-baster looking thing and you put it over the radiator neck opening at operating temp and squeeze the bulb, if the liquid turns yellow then you have co2 in the radiator (better known as a leak).  I've included a link to a site that sells them.

http://www.automotive-diagnostic-tools.com/Head-Gasket-Leak-Detector-Kit-p/uv%20560000.htm

Randy

[b5blue]

Hey I saw that on "Motor Week" this weekend!

[kcederwall08]

okay, I ran the engine at normal temp with the cap off, and it slowly seemed to raise the water level and a little bit would dribble out from the top of the radiator slowly. Could this just be the high flow water pump, the hose inlet is right in front of the cap, so I don't know if thats a factor also.

I put the stock fan back on today, and it runs quite a bit cooler. I'm going to try to return my fan tomarrow (The owner of the store said it would fit, and it had enough cfm's), and get a pusher to see if it helps. Then I'll probably also get a fan shroud for the stock fan. Is there anywhere else to get these from other than year one? They charge about 125$ just for the shroud and like 75$ just for the mounting tabs.

[lisiecki1]

if you tell me your radiator dimensions, i might have one that fits.......if it does it's yours for 100 + shipping including the mounting tabs....other than that, year one is the only other source i know of.

[b5blue]

Now we are getting somewhere!