427 Windsor Cooling Problem

CoupedUp · #1 (**permalink**) 08-08-2009, 09:22 AM

Had a problem with air in my cooling system (I'm assuming this due to my water temp gauge "bouncing" between 190 and 220) which eventually led to a warped head and blown head gasket. Had the heads resurfaced and everything back together. Car runs great, but temp gauge still bouncing and now once the temp gets to 200, it rockets up to 240. I've tried "venting" the air out by cracking open the temp sensor on the manifold. When I did this yesterday when the temp was 230 or so, only steam came out and no water whatsoever. There was plenty of water in the expansion tank. The plan right now is to pull the plugs and see if I am still having an issue with water leakage into the cylinders. I checked the oil and there is no coolant in the oil. Yes, I'm worried about a cracked head or block - I'm thinking a check of the plugs will indicate if there is still a problem with the head/head gasket or block. If I eliminate that, then I will pull the thermostat, although it seems to be opening at 180 just as it should. What would be next? Backflush the radiator? Other than that, there is the water pump.

Ideas and suggestions are appreciated...
Doug

Keithc8 · #2 (**permalink**) 08-08-2009, 10:10 AM

Doug,

Make sure that you are getting all of the air out of the system. They make a set up where you can pull a vacuum on the system to make sure you get the air out and the water in. Make sure that the head gaskets are on the right direction as well and that the thermostat is not sticking. I have seen people not get the system full of water because the thermostat was not open yet. I even put the water hose in the tank and run the car for a while with water on to force more water in. Remember the temp gauge will not read air, only water so if there is no water where the gauge is it will stay on what the last water temp was that it saw. Then when to water makes it back to the gauge it spikes up from the new water temp reading.
Did you have any of these problems before you had the engine apart? I have seen very few cracks in those blocks are heads that you have.

Later, Keith

CoupedUp · #3 (**permalink**) 08-08-2009, 10:16 AM

Hi Keith,

I did have this problem before the last reassembly. It started after the initial replacement of the intake manifold before the head warped. It is possible that I just never got all the air out last time and now again.

I pulled the plugs and they all look good. Spun it over and no water spraying out of the cylinders this time (yeah!). Will now pressure check the system to make sure it is holding pressure. Do they sell this vacuum kit at NAPA, AutoZone, etc.?

Thanks,
Doug

CowtownCobra · #4 (**permalink**) 08-08-2009, 10:23 AM

There must be a thousand threads on this subject, start reading....

CoupedUp · #5 (**permalink**) 08-08-2009, 10:34 AM

That's what I was doing all morning before I started, so following a lot of that advice. Thanks!

CoupedUp · #6 (**permalink**) 08-08-2009, 10:54 AM

Compression check shows a minor concern. All cylinders at 180 - 195 except #4 which was 165. Plug for that cylinder looked fine and consistent with the others. Just resurfaced the heads and replaced the head gaskets. Would expect it to be up there with the others... Either rings not sealing or valves???

Doug

vector1 · #7 (**permalink**) 08-08-2009, 11:27 AM

check your cooling system with a pressure tester?

CoupedUp · #8 (**permalink**) 08-08-2009, 12:03 PM

Yep. System and cap are good. Going to pull the thermostat and see if replacing that helps.

CoupedUp · #9 (**permalink**) 08-08-2009, 01:03 PM

Took out the T-Stat and found a black piece of rubber stuck in the thermostat - probably got in there from the past work of taking the intake manifold and heads off - maybe even a seal internal to the thermostat itself (it was a high-buck t-stat with the wax used to open it for more precision, etc.). Will go get a nice cheap one from NAPA and get my a$$ back on the road (I hope).

Doug

vector1 · #10 (**permalink**) 08-08-2009, 02:12 PM

may i suggest 2 3/16" holes drilled 180 degrees apart in the outer flange? helps to aleviate the temp spikes.

CoupedUp · #11 (**permalink**) 08-08-2009, 05:02 PM

Replacing the t-stat fixed it. The rubber jammed in it was the problem.

Doug

RedBarchetta · #12 (**permalink**) 08-08-2009, 05:17 PM

Atta boy, Doug. With all this practice you're almost as good a mechanic as Brian and I.

CoupedUp · #13 (**permalink**) 08-08-2009, 10:52 PM

I can only dream...

twobjshelbys · #14 (**permalink**) 08-09-2009, 05:20 PM

T-stat was my first guess then water pump, but beware of air bubbles though. The 3/16 holes in the t-stat help with that but I put in a Kirkham overflow tank that contains the t-stat housing and a reservoir at the highest point.

CoupedUp · #15 (**permalink**) 08-09-2009, 08:34 PM

So far, so good... I will definitely keep an eye on it! Thanks to everyone for the responses and advice!

Doug