LocostUSA.com

Any thoughts on what might cause this? After warming up the car (and burping it with this no-spill funnel method), I shut the car off. At this point it is at about 210F when I shut it off. The coolant then rises pretty dramatically with what seems like air bubbles, but you can judge from the video below. Beware of moderately loud audio at the beginning. My thoughts lead me to bad head gasket although while it is running I don't have any bubbles rising after burping it the first time.

https://goo.gl/photos/iFPLY9Zq8wCK8VVM6

You have an air leak somewhere. Rad cap, loose hose clamp, heater core, head gasket

I would start with a coolant system pressure test and or change the rad cap. You should be maintaining 14-15 psi or there about.

Is everything new? anything salvaged that maybe suspect?

_________________
-STu

There is no shame in defeat, so long as the spirit is unconquered

My Build Log

I'm not saying this IS the case......

When you shut off the car at 210. That is temperature @ the temp sensor location with flowing coolant. The boiling point of 50/50 antifreeze is 223°F ,unless under pressure which the no-spill filler doesn't provide. I can imagine a local spot within the engine that may be at, or above that 223 temperature. With the engine shut off and no more coolant flow, cooler coolant cannot move into that hot local area and the coolant boils. it expands and pushes coolant up the funnel. Pressure in the system would raise the boiling point and prevent the expulsion of fluid you are seeing.

But it could be something worse. With other facts not in evidence, what you show is not necessarily an indication of something wrong. I would do a cylinder leak down test or a test for exhaust gasses in the coolant. BTW, 210 at idle? seems a bit high. maybe 180 or 190 is what I would think it should be. What temp thermostat do you have? it shouldn't be running significantly higher then that rating.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Eh3civic has been struggling on this cooling issue for a long time now. Think siege of Leningrad. I know we had a long go around with this in his build log maybe? We have to figure out what is going on here because he can't use the car he built. For a long time now. This must be driving him crazy.

There may well be more than one problem now. I think we've gone thru all the basics, but we need to do it again. So first I'll comment on the current question and then we need to go over the whole issue.

I agree with Rx7locost. If the engine is hot, 210 coolant temp, then when you turn it off it will heat soak the coolant and there would be a little boiling and expanding causes the rise. It should gradually go back down as it cools. Can you put a kitchen thermometer in the reservoir and see what it's temp is? If the temp is under boiling temp of the fluid there can not be bubbles of steam in it. So you would know if it's a cylinder head crack or leak. If the engine is not running the only way for a head crack to cause this would be on a cylinder with stopped on the compression stroke, which is odd it's happening all the time or there are 8 cracks or bad head gasket problems? Weird.

What is the temp of the thermostat? I think it should be 180, there is no crucial benefit for a higher temp when you have a cooling system that is not working.

We should be able to get the car to cool with the hood off and idling. Is it able to do that? There is no point in driving the car if it can't meet this initial standard. Usually people can progress to driving there car before really agonizing over a step like this idle test, but this is an epic battle and we must prepare for this a step at a time.

Wrong head gaskets or water pump turning backwards are high on the list of reasons here. Honestly I don't see other possible causes. Head gaskets can have coolant holes in the wrong places ( different model Fords ) and pumps come in both rotation directions. Parts can be mislabeled or in the wrong boxes so at this point we may to have double check for sanity here.

Get a 180 thermostat, pull the hood and nosecone off and give us a couple of pictures and let's make sure it can idle for an hour without overheating. You might need a window box fan in front of it, but you shouldn't and that would tell us something.

We can fix this!

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

After reading through your build post I can see the frustration.

I have a few questions. If preferred i can re post on your build log.

That is a lovely 302/6 engine. Do you know who assembled it? If it was road going before you bought it? I personally i am always suspect of someone else's work as i am sure you are to. I ask this because i am worried the head may not have been installed properly. IE torqued in sequence to spec. I am suspecting warped heads. I had this issue on a boat with a rebuild chevy 350. AFR is also very specific to head installation.
Also knowing the gaskets in there are correct and not cheap ebay stuff.

Can you post any pictures of your current rad set up? Core dimensions and sizes and do you still have push pull fans??

But back to diagnostic. I recommend a cylinder leak down test, a coolant system pressure test and get a thermometer in that coolant as Horizonjob said with a new 180 Tstat.

_________________
-STu

There is no shame in defeat, so long as the spirit is unconquered

My Build Log

I have to go along with the others. Inevitably, it helps (logic-wise) to go back to the basics.

First, I agree that 210* at idle is awfully hot! Reaslisitically, it should be able to idle all day and never exceed 185-190*.

IMHO, the primary reasons for major cooling problems are:

1) coolant pump not working - often, because someone has re-routed their drive belt to eliminate air pumps, power steering pumps, etc., and the belt has ended up on the wrong side of the pump, causing it to run reversed...which is so inefficient in many pumps that it's almost like having no pump at all.

2) head gasket issues - wrong gaskets (so some coolant passages are blocked off - the only way to tell is to check 'em & replace 'em), blown gasket (sometimes this will result in exhaust pressure actually pressurizing the cooling system until it explodes - thus, the cylinder leak-down test suggested by others), anti-leak coolant additive in the coolant (my stepson is dealing with this, as we speak - he had precisely the same symptoms - he had a small coolant loss issue, used an additive, and ran into this same issue. On pulling the head gaskets, he found that all the coolant passages at the head were almost completely closed off with congealed additive), etc.

3) wrong thermostat, or stuck thermostat. If it stays closed, the rad will basically stay cool, as no coolant is making it that far. Even if the rest of the system is 100%, this will cause massive overheating problems, coolant expansion, etc., as some areas of the engine will be hot enough to spot-flash coolant to steam, yet there's no way for the coolant to get to the radiator.

4) radiator issues - ensure the flow is in the right direction for this particular rad - some need to fill through one port & exhaust out of the other, and having these reversed can impair cooling, although not likely to the degree you're experiencing. Also (although unlikely in a new build), you need to ensure that the radiator's passages are clear & unrestricted to flow.

5) inoperative fan system (again fairly unlikely, as it would be very obvious, but still worth checking).

Those places are where I'd start. I'm no expert, but I do know that sometimes it helps to take a step back & view the forest instead of the many trees...

Good luck...and keep us posted!

_________________
Scratch building, at continental-drift speed, a custom McSoreley-design framed, dual-Weber 45DCOE carburated, Zetec-engined, ridiculously fast money pit.

http://zetec7.webs.com/

The video is just boiling coolant. The reason it shows up when you shut it off is because the waterpump is no longer running to pull it in. It was seconds away from boiling over even if you left it running. When you are burping the air out using the spill-free funnel (so glad someone invented those btw), what exactly are you doing? The reason we need to bleed air out of the cooling system is because the thermostat will not open if there is air under it. It needs coolant contacting it to open. You can also get an air lock in your heater core, and rarely your radiator.

Next time you have the engine running use the funnel. Once you think you have the air out of it, make a mark on the funnel of the coolant level. If you keep seeing bubbles and the coolant level does not go down, it's probably head gasket. If the level drops with the bubbles, it's just an air lock. Headgasket bubbles tend to show as a bubble every few seconds like clockwork.

Maybe give us a video overview of your cooling system and we can help further.

Other thing I would mention, some V8 Fords had a bypass hose that comes off the water pump and goes to top of engine. Maybe look into if your engine was supposed to have one.

Shrouds are good for cooling at any speed. You want them to act as a fence to hold high pressure air in front of the rad, and low behind it forcing more air through. With the fans on, they still force the air to go through the rad rather than around the fan.

Cheers.

_________________
Build log: viewtopic.php?t=9291

TLDR, I'm doing more testing today/tomorrow, but it might be fixed... but I'm not getting my hopes up yet. Could all literally just be air that has been my issue, and ineffective burping.

Now for the long bits;

You guys are great, thanks for the quick responses. To begin, I think the video showed what was simply boiling water as several of you mentioned. I'm running a low ratio of antifreeze/waterwetter and majority is water. I did some more burping, and there are now almost no bubbles showing up. I don't want to get my hopes up, but I let it idle yesterday after burping and it is POSSIBLE that it is no longer over heating. I'll need to check again today. The spill-free funnel has worked out great so far. At first there were a lot of air bubbles, and I was worried about the head gasket. Then there was the thing in the video, which I worried was again the headgasket and basically a cylinder's exhaust pressure escaping into the coolant upon shutting it down, which I don't think is the issue now. The last test with the spill free funnel was almost entirely free of bubbles and a car that seemed to stay at 180, though I need to test again to see if I can use the fan to lower the temp once it rises above 180. Also, keep in mind that I fill everything through the auxillary coolant tank, which is piped into the coolant bypass. I'll do some measurements on the funnel next time to check the levels.

Also, I've got a leakdown tester on the way just in case.

I'll start with a brief description of my setup, and then hit up zetec7's questions as they're in numbered form and I like numbers.

- Mishimoto MMRAD-CIV-92X 3 row radiator
- A couple of heater cores with fans I'm testing for dissipating heat (these are recent additions from desperation, and I understand they could possibly result in more trapped air than helping.
- 2900 CFM shrouded radiator fan
- auxiliary rear reservoir for easier filling, burping, etc

Regarding zetec's stuff;

1) coolant pump not working - This was one of the first things I checked. I was unsure on how to determine the impeller direction without actually removing it, so I just bought a new waterpump that was correct and replaced it. Turns out my old pump was correct anyways after removing it, but I replaced it anyways.

2) head gasket issues - wrong gaskets - This is my current worry, though hope this isn't an issue. The car that the engine came from idled fine and had no cooling issues that I could tell, though to be honest I never actually had it in traffic. I bought the car, stripped it, took the motor and sold the rest. Changed it from fuel injection to carb and put my bits and pieces on to make it all fit in the locost. It was a freshly built engine, so I worried that maybe heat/incorrectly torqued headbolts might have been an issue, but I checked them and they are all torqued to spec (though who knows if they were torqued out of sequence). The car it came out of was a very good condition foxbody mustang, well kept, and very clean, so I hope he was as careful with the engine build.

3) wrong thermostat, or stuck thermostat - Was worried that my 160 degree thermostat was messed up (despite testing in boiling water and confirming it works) so I changed that already.

4) radiator issues - I'm on my third radiator, finally landing on a "non-ebay" radiator. This is in it currently, Mishimoto MMRAD-CIV-92X, a 3 row radiator originally made for civics.

5) inoperative fan system - I'm on my third and favorite fan setup, a single 2900CFM puller with shroud. It all works on a switch, but i'll be changing that to a thermostatic switch once I'm confident everything is working as expected.

Wow! Sounds like you've attacked this from every angle! Still, there has to be something that's been missed.

If the head bolts are properly torqued, and if they were done in stages, I doubt that one or two of them being torqued in the wrong order would do much. As this is a 302, I presume it still has the cast iron heads...if so, they're pretty robust, and errors in torquing order probably wouldn't result in a failure, as long as they were brought to the correct final torque, as it appears they are.

Weird that it was running fine in the car it came out of, and now it's overheating. This being the case, there must be something that's changed in the cooling system between then & now.

BTW, you don't have a heater installed in the car by any chance, do you? Sometimes people overlook such items, which are often one of the highest points in the cooling system, and can hold a LOT of air, stagnating coolant flow, causing spot flashes to steam, extreme coolant volume expansion, etc. Just a thought...I have seen that happen, and burping sometimes isn't enough under those circumstances, and an extra bleeder near the heater is required to purge the air.

Judging by the video, it really does look to me like there's still air in there, somewhere. As you know, air bubbles will often work their way through the system until they get to the water pump. At that time, all coolant circulation ceases (as the pump's just spinning in air - the impeller is designed to push water, not air or steam), heat builds, more pressure ensues, etc. etc.

Just throwin' ideas out there...sooner or later, someone's going to hit on the right one!

_________________
Scratch building, at continental-drift speed, a custom McSoreley-design framed, dual-Weber 45DCOE carburated, Zetec-engined, ridiculously fast money pit.

http://zetec7.webs.com/

I'll add a bleeder on the auxiliary cores (the tubing makes an upside down U shape), that's a great idea. Also, it has aluminum aftermarket heads (afr 165 heads).

Oh, okay. The aluminum heads do add a wrinkle, as they are susceptible to uneven torquing patterns. Well, if the extra bleeder doesn't help, you may be looking at head gaskets, although I doubt it - it wouldn't have run cool originally if that were the case. I'm still going with the trapped-air-pocket-in-a-high-point opinion, at this stage. Let's hope I'm right - it would be the easiest & cheapest fix!

_________________
Scratch building, at continental-drift speed, a custom McSoreley-design framed, dual-Weber 45DCOE carburated, Zetec-engined, ridiculously fast money pit.

http://zetec7.webs.com/

I think you should remove any auxiliary cores until you have your problem understood. Yu don't want to be debugging wether you still have air bubbles in your extra cores that you don't need to begin with. Just get the car to where it can idle in the driveway for as long as it has gas, without over heating. You should hear the cooling fan come on and then turn off periodically - just like your other street cars if you need to idle them in traffic or for whatever reason. I would remove the hood and maybe nosecone, just like your video was showing.

Leave your filler funnel thingie on too and mark were the fluid is when the engine is cold and hot. It should be repeatable every time you do this.

I don't know what to suggest to make sure there are not air bubbles in your heads when you start this, but adding extra cooling radiators will not help that. Some heads have provisions for steam vents.

Idling the car should not produce so much heat that any half way reasonable radiator and cooling fan can't deal with it.WHile the cooling fan is cycling you should be able to see a high and low temperature in the water in your funnel. Using extra fans on the radiator will never reduce the engine tmep below 180 because the thermostat should shut the radiator off. Both the cooling fan and the engine thermostat do not turn on and off at the same temperature or at the same temperature as each other. Otherwise they would potentially be turning on and off at an infinite number of times per second. You should be able to see all this happening with a thermometer in your funnel ( kitchen thermometer ). You can tell when the engine thermostat open because you will feel a big increase in heat coming from the radiator.

How does your coolant box with the filler funnel connect into your system? Since it's on the back of the motor do the lines to it loop downwards then up? That would help make the heads an air trap.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

i could start at the beginning and say,

1. the aluminum heads, when fitting these were the head bolts new or the old ones, the new ones are torque to yeald and should be replaced if removed, they should also have special hardened washers under the head of the bolt.

2. i need to see the inlet manifold you are using and the water pump, does the water pump have a elbow shaped hose from the top to the front of the inlet manifold next to the thermostat housing?

3. is the thermostat housing the highest point on the engine disregarding the carb and uncooled intake manifold?

4. are there any cooling pipes on the water pump other than the large port to the bottom of the radiator?
are there any water outlets on the inlet manifold adjacent to the thermostat housing?

5. does the engine sit in the car with a "nose up" attitude?

-------------------------------------------------------------------------------------------

now for the header tank

1. is it the highest point in the cooling system?

2. does the pressure cap fit on the header tank or somewhere else in the system like the radiator?

3. how many quarts does the header tank hold?

--------------------------------------------------------------------------------------------------------

radiator

1. core dimensions and thickness

2. what is it made of?

3. where are the tanks on the radiator?

4. is the top hose spigot on the radiator above, level with or below the thermostat housing?

------------------------------------------------------------------------------------------------------

other stuff to check

1. when you purchased the new water pump did you buy it for a fuel injected engine, was it the same as the one that came off the engine and how does it compare to say a 66 mustang with a 289?

2. does the water pump have a "v" belt pulley or a serpentine pulley or is it a shorty pump?

3. the block, is there any traces of water in the oil because the 302 blocks suffered from core shift worse than most other engines, is the block from Mexico or Dearbourn as the Mexican blocks are much better?

4. when they rebuilt the engine was it re bored and to what size as more than .030 over may have weakened the cylinder walls, usually on the back cylinders so you could have a pin hole in the cylinder which is sometimes exposed to above the rings and sometimes below the rings?

5. are you sure that the electric fan or fans are moving air in the right direction, if you have a pusher and a puller they must be wired oppositely.

6. is there a crossover passage at the rear of the inlet manifold or is it blanking off the water passages in the back of the heads?

just some thoughts.

_________________
this story shall the good man teach his son,
and chrispin chrispian shall ne'er go by,
from this day to the end of the world.
but we in it shall be remembered.

If his timing is a little off (advanced) couldn't that cause overheating at idle?

_________________
-STu

There is no shame in defeat, so long as the spirit is unconquered

My Build Log

You say you switched to a carb, does the new intake use the same coolant flow as the EFI one did? I'm guessing it probably does, but just a though. I have a V6 from a fwd in my car, and the res version of the engine uses a different intake and different head gaskets. The thermostat is also at the other end of the engine in the fwd version though.
Kristian

_________________
V6 in a book frame build. Now registered.
viewtopic.php?f=35&t=7587
viewtopic.php?f=33&t=18172