overheating problem

[oino]

I double checked the timing at tdc. The dist points right at #1.

The car runs great at 12*, other then the temp problem.
I didn't move the dist or the crank when I changed the heads and manifold. Came out and went back in the same way.
No smoke from the pipes.

One thing! With it at 12* the air flow entering the throttle body sounds like a jet. Like it's forcing the air past the flappy things.
At 8* the air entering the throttle body sounds fine.

 

[oino]

Chaning back to 12*. Then redoing the efi setup again. Then I'm going to try and change my afr. It's at 13.8 right now. Going to change it to 12.5

 

[Screaming Metal]

OK, well we know its not your static timing . Look over your manifold and the EFI really careful and make sure theres no vacuum leak anywhere, removed intake fitting or missing vacuum cap. Crank it up and spray some cleaner on the intake around your injectors and at the intake face, making sure no really big intake leaks are present.
Now, your running electric fans hooked to your EFI, Right? They are coming on, but coming on late, correct? Do you have a heat gun? if you do, verify the temp at the heads.

Try this, just pull your thermostat, put it back together, and see if it runs cooler, after resetting your EFI.
If its heating up really fast, like in a few minutes time, your either getting exhaust gas into your cooling system, blocked waterflow at the head, or WAAAAY to lean. Will the motor rev good? Or does it stumble all over the place?

I'll check back in in a hour....its dyno time....

 

[oino]

ok, got it running again at 12*. No more comm error.
Did change the afr to 12.5, got to hot to see if that did agian.
Waiting for it to cool off again. Then I'll test the rev and remove the t-stat

 

[oino]

Rev is crappy. It's real stumbly.
I did remove the thermostat and it keeps a study temp on both the efi/manifold temp gauge and the head temp gauge.
Take a bit longer to heat up and the fan comes on fine, but still overheads, now just with the same readings....

 

[one finger john]

Hey Chris, can you use the present manifold and pull the throttle body off and reinstall the carb? It is a known good constant-right? If the engine runs fine and the car does not overheat then it is probably the EFI set up. Also, does the manifold have the water outlets on ends? You know, the outlets that are placed directly over the water passages that exit the heads. If you do, install a sending unit in each of the outlets at the front of the engine and record the temps. Then swap the sending units and see if the temps are the same as the initial installation. OR are they different. If different, find out why (perhaps bad sending unit). Also, are both sending units the same manufacturer and the same temp range? Are the gauges the same? On your dash, do you have TWO temp gauges, one for the cylinder water temp and one for the EFI? Might as well have a third sender/gauge in the other head and have three different opinions. Sounds like the United Nations.

If you do the outlet swap of the sending units try to find a known good MECHANICAL gauge and go off that.

Don't get Mike pissed 'cause you're burning band width.

Last thought, if it really is 107* with 95% humidity and the car is inside the garage, push the car out to the driveway and let it breath fresh air. It will naturally run hot in the garage. The radiator is a mustang unit, right? Or is it an aluminum unit. Anyway, when it starts to get warm spray cold water on the front of the radiator and see if the temp goes down. If it does I would think you need more radiator surface area to dissipate the heat. Remember, it isn't the amount of water in the radiator that cools the engine, it is the square inches of surface area that cools the engine.

John

 

[oino]

Can't go back to the carb. That would requires changing the fuel pump, and line.
Plus I sold the carb and can't change it back anyways.

 

[Wild Mango]

IMHO If the only symptom of "overheating" is an instrument telling you that, and it does not agree with any other instrumentation, I would check the instrument. Over the years we have seen many cars come in the shop "overheating" or "running hot", but otherwise running fine and not losing coolant through leaks or boiling, it's the instrument every time. Headers are going to be way hotter than the head, and the inlet manifold is going to be way cooler than the head, especially in a running engine. We use digital thermometers with the probe on a flex, you can measure the water temp coming out of the thermostat when it opens to see if it is close to the thermostat rating, measure the temp of the top tank in the radiator and the bottom delivery temperature, all sorts of useful things to know. Check the thing is operating correctly by boiling the kettle and making sure the reading is about 212F, 100C before you use it. Hobby electronics stores like the old Radio Shack have such devices. JM2CW
P.S. any old drag racer like me or Screamin' will tell you why we have electric water pumps, it's so as we can turn the pump off when its close to our turn to stage and get that bad boy good and damn hot, 230/240F, pick up another one or two HP to make the difference. Long as she don't boil the coolant out, she'll be fine. (its the 8500rpm Banzai high gear charge in the traps that does the damage )

 

[oino]

k, Got a heat reading gun. It is reading the same as both gauges (give or take a degree or 2.) Heads reading a little hotter then the manifold.
Then my headers are ready a bit hotter then the heads.
Still over heating. I cut the car off at just before 200.

 

[2old2fast]

When the engine is reading 200 +- what is the top of the radiator reading , the core , the bottom tank ??
dave

 

[oino]

When the engine is reading 200 +- what is the top of the radiator reading , the core , the bottom tank ??
dave

You could have asked that question about an hour ago.
I returned the gun. I Borrowed it. I'll ask again tomorrow if I can use it again.
It's football time here right now. Ridiculous I say. Damn town shuts down for it.

 

[oino]

I did get it to run richer. Changed the afr to 11.6. Any lower its craps out and I get big puff of black smoke.
11.6 seems to be the sweet spot for richness.
But still runs hot.
Looking like I might have to pull it all apart. That will suck cash wise. I'll keep at it til next Thurday. If no go then I'll pull it apart.

 

[Screaming Metal]

Ok, I see all your info now. Theres one more test. Crank her up, take off your radiator cap, look down into the coolant, let her run for a little while. OK, do you see any white foam or bubbles? Is the coolant smoking as it starts flowing? Make sure you coolant is being pumped, you should see the coolant flow by. If not, you might have lost your impeller.

Is your waterpump belt good and tight? Fluid is moving, right?????? No coolant dripping from the weep hole on the pump, correct?

If all this checks out, and theres no waterpump issue and no mass airleaks on the intake, I'd pull the heads.
You've verified the Thermostat is working, you have coolant in the system, timing is good, no external load on the motor to make it overheat. The EFI isn't running too lean. Good clean gas. No blockage of airflow over the radiator. The
Either the head gaskets leaking, the coolant passages on the head surface are covered up. I'd also test the heads for cracks.

 

[Screaming Metal]

Theres one other thing to look for, pull all your plugs. Are they tan? or a light Brown? They don't have blisters on the electrodes, Do they? If so, that would be a sign of running too lean. Are any of them wet? If they are, Smell them, is it gas oil or coolant? If oil, you've got a intake leak in the valley, and it should show up as smoke out the exhaust. If its water, your head gasket is seeping or you've possibly got a leaking head bolt. You aren't running MLS head gaskets, are you? Those take a really slick surface to seal....
If they're not wet, and look good, I'd say its a good bet you'll probably have to pull the heads....head gaskets are probably the cause

 

[oino]

Ok, I see all your info now. Theres one more test. Crank her up, take off your radiator cap, look down into the coolant, let her run for a little while. OK, do you see any white foam or bubbles? Is the coolant smoking as it starts flowing? Make sure you coolant is being pumped, you should see the coolant flow by. If not, you might have lost your impeller.

Is your waterpump belt good and tight? Fluid is moving, right?????? No coolant dripping from the weep hole on the pump, correct?

If all this checks out, and theres no waterpump issue and no mass airleaks on the intake, I'd pull the heads.
You've verified the Thermostat is working, you have coolant in the system, timing is good, no external load on the motor to make it overheat. The EFI isn't running too lean. Good clean gas. No blockage of airflow over the radiator. The
Either the head gaskets leaking, the coolant passages on the head surface are covered up. I'd also test the heads for cracks.

Waterpump belt tight.
Now not sure how to tell if the fluid is moving. I have a t radiator. The neck come out from the radiator. Can't see down in.
I did let it run with the cap off until the water start to come up and out of the neck. This happend at 170.
Gas is new and fresh.
Out of the fill neck why I was waiting. No white foam, only a few small air bubbles.
Should the fluid raise up out of the neck with no t-stat in there?

 

[Screaming Metal]

Some motors do do that....butI thought you might have a regular radiator with just a shell over it. I was just trying to think of things to check, to keep you from pulling those heads....
Without a thermostat in it, it should just pump your water around in a circle, unless you have a blockage. Which those head gaskets could be covering up.
All things look like its a coolant blockage problem somewhere in the motor, or combustion chamber gasses getting into the coolant....

 

[oino]

Some motors do do that....butI thought you might have a regular radiator with just a shell over it. I was just trying to think of things to check, to keep you from pulling those heads....
Without a thermostat in it, it should just pump your water around in a circle, unless you have a blockage. Which those head gaskets could be covering up.
All things look like its a coolant blockage problem somewhere in the motor, or combustion chamber gasses getting into the coolant....

Ya, I'm thinking head gaskets too. I put them in the way it said.. Maybe I overlooked something.

I got a plug out. It black and dry. But smells like oil.

 

[Screaming Metal]

Did you have any problems with the line up dowels on the block?

 

[oino]

Did you have any problems with the line up dowels on the block?

Nope, Head gaskets and heads went on great.

ok, I think I found something. Was just out putting the plug in and I noticed on the ground below the starter about 7-10 drops of oil.
I looked up behind the head and I see a little puddle of oil.
Could that be it? vacuum and oil leak from the back of the manifold.

That oil on the ground could have been there before, but with all the anti. thats been on the ground and cleaning that up I've most likly over looked it.

 

[oino]

look like this in the front of the same head. I think its coming out where the manifold and the head meet in the corners.