Need help please - new engine fitted - spewing coolant from rad on every journey

[cutes6]

I recently built a 302 engine and have installed it and it works very well - so far so good - it's a 72 block.

However I have one big problem - every time I run the car it spews coolant out of the radiator overflow. It does not overheat according to the gauge and the temp does everything you would expect - it rises and falls as expected. The temp gauge is however overall higher than the previous engine but is always around the half way mark whereas the previous engine was around the quarter mark. I did put this down to cleaning the sender unit and it being a new engine. the top hose is always hotter then the bottom hose.

When putting the engine together I did buy a new water pump with a RH outlet as from the drivers seat to match the radiator connections. This pump appeared to have the same number of impellors with the same shape impellors as the pump that came with the engine.

I have increased the rad cap to 15lbs from 13lbs and I have also retested the thermostat in a boiling pan and it is ok.

We ran the engine on tickover without the cap on this morning and my mate who has good experience with engines reckons the movement of water in the radiator was too fast - the water was moving from the top hose connection to the other side of the rad so the flow seems to be in the right direction.

I have no water leaks and the coolant was about 50/50 antifreeze but will be less now.

I have studied the internet last night and I seem to be left with these possibilities -
1, The water is being over driven and aerating. My water pulley is the same one from the old engine and the same diameter as the pulley I was given with the engine ?

2, The head gaskets are leaking severely, introducing combusted hot air into the water - I did have the heads lightly skimmed though and fitted the recommended Felpro gaskets so I hope this is not the case.

3, Finally and the one I hope it is - I have fitted a reverse flow pump, but having searched the internet I am unable to come up with an explanation of how to tell the difference between the 2 types of pump

So as you can see I am stuck and need to draw on your experience to help in anyway please as I am at my wits end.

thanks

PS - I have just looked under the car and a substantial amount of water has leaked from a rubber pipe which hangs down at the bottom of the bulk head on passenger side I believe this has something to do with the heater unit or my air con - it seems like water as opposed to coolant tho, and this has just started today and I have driven 80 miles with the air con on. I hope increasing the rad cap to 15lbs has not sprung a leak !

The carpet is not wet however the underneath of the heater/ air con unit is wet - is this pipe like a catch drain for condensed water from the air con bit hence the clear water ?.

you have just gotta love these cars to keep going !!!!

 

[brianj5600]

It may just be from expansion. You need to know the actual temp to tell if it is overheating. I know a guy that runs his coolant low with the engine stone cold. If he adds it will overflow out the tube. Once the level sets itself it does not overflow anymore.

 

[cutes6]

Thanks for your reply,

I must get a more accurate reading of the engine temp as I am relying on the gauge although this never goes much above half.

I have just looked at my water level now it is cold and the water is well below the holes down the inside of the rad - it took 4 litres of water to top it back up to just above these wholes yesterday after a run which must be too low.

 

[10secgoal]

Hate to tell ya it's probably the head gaskets. Who's gaskets did you use ? We just went through this about 6 months ago. Brand new motor. Would puke coolant everywhere, on command. Would not fail a block check, would not over heat. Drove fine until you buried your foot in it. Everything told us HG, but we couldn't prove it. We ran out of theories, and things to check. Replaced the HG's, and left the next day, just fine.

 

[cutes6]

Hi

I used the Felpro ones with the silicon beading around the waterways and I also used some new ARP head bolts.

I have decided that tomorrow I will take the timing chain cover and the water pump off my redundant 289 motor as I know these worked OK and put them on my new engine. I want to know if the new water pump I fitted is causing this issue or not.

I have read that if you have the wrong flow pump on then you will get the same issues. I still do not know how to tell the difference between a reverse flow pump and a normal one.

This is a real PITA to make these changes though as my new engine is completely water and oil tight.

If that does not work then it will be head gasket time !!!!

 

[ForceFed70]

Time for a compression test....

 

[94Blue302GT]

I had a similar problem once... heads
I think they may have actually been cracked though.

Do you have an overflow, or are you refering to it just coming out the rad. cap?
I would get an overflow if you don't have one already, and watch the levels on that.
Summit and jegs have them for fairly cheap.

 

[Rusty67]

Whats the part number on the water pump you have on the motor right now ?

 

[D.Hearne]

Could very well be the head gaskets are on backwards. Look at the lower front corner of both heads, if the gaskets are installed correctly, you will see a portion of the head gasket protruding out from under the head in that corner. There's sort of a notch in the head that doesn't cover the block deck there. The gasket should cover that deck area. As fo rhe water coming out the heater A/C drain, that sounds like the increased pressure has ruptured the heater core. Not unusual for that to happen, even with new cores. Just bypass the heater till you get the other problem resolved. Third: BUY AND INSTALL A MECHANICAL TEMP GAUGE, PRONTO!!!!!!! relying on the factory gauge to tell you what temp the coolant is, is an excersise in futility!!!!!!!!! You're not the first here to have this go-round with a factory gauge.

 

[BarnStang]

If you do pull your new water pump, you can tell by the pitch of the impeller blades compared to you 289 pump. If the new one is reverse rotation, the impeller pitch will not match the 289 pump impeller. Or would be faster and easier to post the part number of the new pump.

 

[cutes6]

Sorry for taking a while to reply

update - well this morning I set about fitting my old 289 pump and luckily it fit the cam chain housing.

Now I took it for a hard drive and strangely the over all temp is much lower now and whilst it did blow some water out it was no where near the quantity of yesterday and this was after a 30 mile run at around 3,500 - 4,000 revs (about 85 to 100 mph with my gearing) so a big improvement.

when it was still hot I carefully removed the cap and the coolant was very frothy - now this could be caused by the water getting aerated or I do have a leak in the heads somewhere - but why the improvement ?

The only number I can find on the pump I took off was PH 303.

Here is a link to the 289 pump impellor design that is now on which is very different to the one I took off this had separate " L " shape exposed fingers.

http://i539.photobucket.com/albums/ff358/bad-ass-67/DSC00378.jpg - this is the same as my water pump not the actual one.

After the first run the water was just above the coolant holes in the rad, but after the second run it had dropped below so I still have a problem - or the natural level is somewhat lower with this engine.

I also checked to see if the head gaskets protrude at the front lower part and they do on both sides, I hope this means they are on OK.

Thanks for every one's help so far.

 

[Rusty67]

Looks like your old pump was using an impleller instead of a propeller. Impellers are much more efficient at moving water which would explain the lower overall engine temps. I believe impellers are also less prone to cavitation (or how ever it is spelled), basically they don't froth the coolant as much. I would suguest adding an over flow catch can and seeing if that fixes the problem. My old 289 didn't have a catch can and would drain out coolant until the coolant was too low. Same thing with the 5.0 I put in. Now that I have an overflow tank I don't have that problem anymore.

 

[D.Hearne]

If you have a head gasket leaking compression into the coolant, that can be identified by opening the radiator cap after the engine's been run for as little as a minute. Do this in the morning on a cold start. If there's pressure in the radiator after a minute's time, you've got a compression leak. Three possibilities for the other pump not cooling the motor more: One, the pump is a 79-84 Mustang pump, which has a std rotation housing, but a reverse rotation impeller. Two: that pump is a std rotation but has a smaller, lower volume impeller than the old 289 pump. Lastly, the other pump dosen't match the timing cover that the 289 pump does. That 289 pump you have pics of, uses a different timing cover than the later pumps use. The pumps are not interchageable between covers.

 

[cutes6]

Well I thought I would provide an update -

After changing the water pump things are a lot better. After several runs of normal driving it has leaked a very small amount when turned off and on some occasons it does not leak at all.

Each morning the water level has dropped a fraction but getting less.

A friend said I must leave it for a few days without taking the cap of all of the the and wait to see what level it settles to and take it from there.

Each time I have taken the cap off in the morning there is still pressure in the system and it gurgles, when I tried the 1 minute test from cold whilst there was no noticable pressure when I took the cap of there was a lot of froth in there - so I do believe that it is not fixed - unless the froth was because the system still had air in from changing the water pump.

I am going to leave it alone for the next week or so, keep eye on the running temp and see if it does settle to a level and is stable.

I must thenk everyone who has contributed to this thread and tried to help, thanks.

 

[BarnStang]

You will have air in the system till it all works out, especially if the water jacket was empty. Don't know about leaving it sit for a few days, running it will get the air out the fastest. It sounds lke that is whats happening if it's using less and less water. Keep topping it off, it will settle to it's own level and not push anymore water out. The overflow can will make this easier and faster though.

 

[Decurion]

Hate to tell ya it's probably the head gaskets. Who's gaskets did you use ? We just went through this about 6 months ago. Brand new motor. Would puke coolant everywhere, on command. Would not fail a block check, would not over heat. Drove fine until you buried your foot in it. Everything told us HG, but we couldn't prove it. We ran out of theories, and things to check. Replaced the HG's, and left the next day, just fine.

I had exactly the same problem on my car, but 2 sets of head gaskets did NOT fix the problem. I finally got mad and put new heads on it and never had a problem after that. I sold the old heads on eBay and the buyer emailed me a while later and said the heads worked great. Go figure.

 

[CraigMBA]

Why no puke (overflow) tank?

 

[cutes6]

Update,

well I decided to take the heads off and have a look to see if there was anything obvious to fix my loss of coolant problem but everything looked fine with no obvious leaks across the head gaskets etc.

One of the inlet manifold gaskets looked a bit rough but that was it.

whilst I was there given that this new engine has now done 800 miles, I looked at the Cam lobes, valve lifters, valves, tappets and push rods and the bores, I am pleased to say everything looked fine although I think I have a lazy lifter from time to time first thing in the morning.

Anyway I replaced the gaskets and re assembled and !!!!!!!!!!

everything seems fine now - yippeeeeeeeeee.

I can tell that there is a huge improvement as the pressure in the cooling system is nothing like what I had before, so I need to go for a good drive now to confirm everything.

A couple of questions

1, should I re torque the head bolts ?

2, when setting the float heights on my Holley 600 should the fuel just, and I mean just be below the sight holes or a bit below or should it just dribble out ?

Oh and I have just worked out that I have a mechanical secondary which is not good with auto apparently so will have to look out for a vacuum secondary