Cougar XR-7 water loss.

Topic: Cougar XR-7 water loss. (Read 919 times) previous topic - next topic

Cougar XR-7 water loss.

October 08, 2006, 08:55:48 PM

Hello,

It's been a couple months since I've posted. The question I have is on my dad's 1987 cougar XR-7 that has had the '89 mustang 5.0 HO and mass air swap. For some weird reason the cooling system keeps losing water somewhere. There are no leaks on the ground and while it is running there is no steam or leaks. There is no sign of anything coming from the exhaust at all, there is no water in the oil either. It has us stumped because before we put the engine in, all cooling related parts were replaced; i.e. water pump, thermostat, hoses etc. However, after about five to seven days almost a gallon has to be added! The car runs really strong and performs well especially compared to the non-HO 5.0. Any ideas?

Cougar XR-7 water loss.

Reply #1 – October 08, 2006, 09:28:31 PM

Run a compression test on the radiator.
Check your hoses for pinholes.
Check to make sure the thermostat is in fact opening.

Cougar XR-7 water loss.

Reply #2 – October 10, 2006, 03:50:08 PM

okay, I'll give it a shot. Could there be a slow leak maybe in the head gasket?

Cougar XR-7 water loss.

Reply #3 – October 10, 2006, 04:00:40 PM

Doubtful, but anything's possible. I don't know enough to make an armchair diagnosis at this point....

You say it's making a gallon of water disappear in 5 to 7 days. How many miles are driven in a 5 to 7 day period?

It almost sounds as if the themostat isn't opening or a hose is sucking air in. Either way coolant would back up into your overflow tank and run out the top when full. You would most likely notice a high fluid level in the overflow tank and low fluid in the radiator if this is indeed what is happening.

Cougar XR-7 water loss.

Reply #4 – October 28, 2006, 02:23:49 PM

Hey,

I think I've isolated the problem to the heater core. When you turn on the defroster a serious fog comes out of the vents and continues to stay there, it won't dissipate at all. The car was bought from the original owner almost ten years ago and as far as I know has never been replaced. Since I'm not finding anything else that could be the problem, I've decided to go ahead and replace it.

Now the question is, how difficult is it to replace? I have the digital dash and floor shifter. Am I going to have to remove the console and then the dash? What is the difficulty on a scale of 1-10, 10 being horrible:yuck: Thanks for you guys help.

Cougar XR-7 water loss.

Reply #5 – October 28, 2006, 08:31:46 PM

Yes, you will have to pull the console out. You may be able to crank the floor shifter back to '1' and have enough room.
I just did the heater core in my '86 XR-7... it really isn't that bad. I didn't mind it that much.
Just take your time and remember everything you do! Make sure you get all of the bolts, and don't pull too hard on the dash. Nice and easy does it.

Oh, be prepared for plenty of coolant to be in that heater box. Have some towels laying around.

Cougar XR-7 water loss.

Reply #6 – October 29, 2006, 07:27:26 AM

Standard viewing:

http://www.coolcats.net/tech/troubleshooting/heatercore.html

Cougar XR-7 water loss.

Reply #7 – November 05, 2006, 03:35:36 PM

Well, i'm in the process right now of changing that heater core. Man, there ALOT more wires back there than my mustang GT. I found that the heater core was leaking in about three areas! should have it done here in about 2 hours.

Cougar XR-7 water loss.

Reply #8 – November 06, 2006, 07:48:28 AM

That write-up saved me an A$$LOAD of time. Most shops will charge 10 hours of labor on that.