jackndelphine

Hi Everyone, its been a while since I have been in the forum, its been a busy summer!! I have a 66 Mustang with a 289 and yesterday I had to take it about 100 miles round trip into work because my daily driver is down right now, it was kinda hot out, about 80 or so, and the car was running great as usuall. I go up to the hwy and hit about 65mph and I look at the temp gauge and its at about 200 degrees, so I figured its a little higher than normal and its hot out. So I keep watching it and its keeps climbing, it hits about 215-220 and then I slow it down to about 50mph/2000rpm and turn the heat on and she cools down, I hit the gas a little to pass someone and it shoots right up, so Islowed back down to about 50 and continued on , got off the hwy andit cooled back down and I made it to work. So later on I checked the coolant, it was low (again....I checked before I left my house) so Itopped it off, started it, and checked for flow, the water didnt move, I hit the gas and it starts gulping and over flowing out of the radiator (car was cool) So I decided to remove the new thermostat I had just put in about a month ago, I started it, had massive flow and then gulping. I topped it off took it for a ride, and the same thing happened, temp up to about 210. So I retarded the timing a little and decided to drive home, well I had to do 45 the whole way home, but now I felt hesitation down low and it would seem to surge a little going up inclines. The temp gauge acted like a 2nd speedometer and never cooled down till I got off the hwy. I noticed that the coolant is milky looking, but the oil is clean, I have no white smoke. But the coolant keeps disapearing, the faster I go, the hotter it runs and I am getting more and more of a dead spot when I take off from a stop. So I am wondering ifthe head gasket is bad and exhaust gas is getting into the cooling system. If I get time this weekend I would like to check the compression, but I guess I should just look for a cylinder bleeding off faster than another? Anyway, anyideas would be appreciated.-------Jack

JMD

Yea, IMO you have compression/combustion gasses being forced into the cooling system. When the radiator is constantly puking, even when cold/cool, there is little or no doubt.

Could be just a head gasket, or it might be a cracked head, or both.. I would guess about 60% it is just a head gasket... Upon disassembly, you should be able to see evidence of a "trail" on the head gasket where the compression is traveling toa water passage. This will help to confirm that a head gasket is the issue. If you do not see evidence of this type of trail, you will need to pay particular attention to the heads.

Usually a compression test will find this issue, but sometimes it wont, because in the early stages it may take the pressure of combustion to cause the leak. With compression levelpressure alone, the leak may be too slow to detect using a leak down test.

Be aware that a leak of this type has the potential to "hydrolock" your engine with the possibility of devastating results.... I would not drive it (or even start it) until the situation is resolved.

USMCrebel

+1 to that
have you done a radiator flush, just outta curosity? if yes, put all your time int your DD, and pull the 289, strip it and check it (well the heads anyways). i would be willing to bet your cooling system needs a flush though, aslo after inspecting the heads i would check the block as well even if you know nothing is wrong go through the whole process to ensure catostrophic failure is avoided.

jackndelphine

Yes, I flushedthesystemabout a month ago, and the coolant was clean for a little while then started getting all muddy looking, but I am wondering if it is looking like that from all the exhaust gases getting pumped into it? When I was working on it yesterday antifreeze got all over the top of the radiator and it was a tan color, then I looked at it about an hour later and it was green again, thats why I am thinking its air causing it to change, its the strangest thing I have ever seen! I think the engine was getting hydrolocked and thats probably why when I pulled the t stat and put it back together then started it with the cap off I had flow, but I bet when I put that cap back on the exhaust gases were causing the flow to get restricted, maybee untill the coolant would get forced out of the overflow. Thats all hypothetical, but I guess I will check the compression for the heck of it, and just compare one cylinder to another then take the heads off and see whats going on. The season is pretty much over, so its no big deal to have the car laid up. I don't think I have catstrophic failure, I guess I got lucky, cause it still seemed to have plenty of power, even at 220 degrees Ha! So I guess I will just hope for the best. Anyway thanks for the advice----Jack

JMD

It sucks! Yea, I would do a compression and a leak down test also, upon re-reading my prior post it looks as if I am saying not to do it, but I didn't mean to say that... The tests will probably help you to at least know which head to pull. What I was trying to say is that you should not be really surprised if the tests don't show a problem, I just didn't say it very well.

I hope all goes as well as can be expected!

jackndelphine

I understood what you meant, basically you were saying that it might, or might not reveal the cause of the problem by checking compression. Hopefully when I get the thing apart I can physically see the problem, that always makes me feel better!! Ha!! The more I think about it, the more stuff I remember, and to be honest, I should have seen this coming, the car has been acting stranger and stranger progressivly for the last few months, it felt slower and the temp problem got slowly worse and worse, it used to only go up to about 190 then I would slow down to 60 65 and it would be fine, and the gulping, this I noticed last time I had to refill it with anti freeze, which was when I did the cam and had the intake off, I filled it after I got everything together and started it, and it seemed like it had air pockets in the cooling system because before the t stat opened it would start gushing fluid out then the t stat would open, suck all the anti freeze in, then start to overheat right in the driveway, so I would have to add then quickly put the cap on or it would gush out all over, I guess that should have been an indicator that there was a problem. I just hope the intake gasket isnt screwed up or the wrong one or something like that. Anyway, I will figure it all out when I get it ripped apart, whatever it is, I will fix it.------Jack

boogerschnot

Sounds like the head gasket would be the culpret.. Make sure that if you do run it, your radiator cap pressure release works,, Mine failed back in high school and blew the entire top off of the radiator, it peeled back like a sardine can all because of a failed head gasket.. It was an easy fix, thank god,, if you call replacing a head gasket easy.. Better than replacing a block though if you know what I mean....

JMD

This is a very good point.

Made me think of something else, if a vehicle has to be run with a coolant leak (internal or external) the odds of reaching the destination can usually be improved by loosening the radiator cap to the point where it will no longer hold pressure in the system. With zero pressure, the coolant will stay with you longer, but if the vehicle temp exceeds boiling point at atmospheric pressure, or there is somuch combustion gassesentering the system that the coolant will not stay in,all bets are off.

jackndelphine

I'm not planning on running it anymore untill its fixed, I am probably going to do it this weekend, now I just have to find out if there are differences between intake and head gaskets for a 4 barrel head and a 2 barrel head. I have stock heads on my engine but I am running a 4 barrel carb, the engine was originally a 2 barrel engine so I am guessing I have 2 barrel heads, but I am not sure, do any of you guys know how I can tell what heads I have on my car, I know for sure they are stock Ford heads, I am guessing there will be numbers on the heads to identify them, I just need to know what I am looking for. Oh and what brand head gaskets do you guys recommend? I was gonna use Felpro, I have used them in the past and never had any problems.-----Jack