Okay...I have read all the posts about overheating and the mystery coolant loss and I believe it to be the head gasket but just to review:

I just got our '91 wagon (277,000 miles) back on the road after sitting for about 6 months. She didn't pass smog because of overheating on the dyno. I changed out the radiator and cooling fan...original radiator and obvious broken fan...and no more overheating and passed smog. I also installed a new O2 sensor and she's runs great. However,

I have a mystery coolant disappearance. The only place that is obvious is at the overflow tank as it is always way full but the radiator loses enough coolant to warrant topping it off once a week. I replaced the original rad cap. But now she's gotten progressively harder to start in the mornings or after sitting for a while like running into the store, etc...missing and misfiring. I pulled the plugs when she wouldn't start this morning and they were wet so I dried them off and replaced and she started easier but still not right. I also noticed hearing bubbling sound coming from the system at shut down. I am going to replace the upper/lower hoses and t-stat today just because they ought to be...original t-stat. I don't believe it's a t-stat because it works fine when the coolant is topped off. Once she's started and cleared she runs great!

With all that said...maybe I'm just looking for confirmation on the head gasket. All symptoms point that way and I dread doing it as it looks like a pain in the arse. Any input is appreciated...thanks.

Darol

I dont know if I have the same issue but I check my reservoir tank & it was very low & then checked the rad & it was also low. I'm going to check again today & see if its gone down.. its been a week since I last topped up.

Hopefully its not headgasket like you said... if that's the case I'd rather drop in a motor with new belts & seals ready to go!

Do you have any visible leaks?

No visible leaks but all the other signs are there. It must be internal as she is hard to start and rough running for the first few minutes in the morning. She doesn't run hot until the coolant level drops after about a week of driving and then add about a quart and we're good to go again. I agree...I'm seriously thinking about pulling the engine to do this one right. The Chilton manual says I have to remove a couple of motor mounts and move the engine anyway. We'll have to think about this one real hard and see where the pay off is.

All done...new head gasket and all associated gaskets and seals in place and running. It wasn't too bad for the first time...the hard part was assembly and putting things back in the correct order such as the AC compressor bracket on before the alternator bracket. After 3 times in and out, I'm now an expert on '91 Accord alternator R & R. The biggest problem was trying to get the stock size AC/alternator belt on...I couldn't get it to go no matter what. So ingenuity took over and I just put a longer belt on...problem solved. Now time will tell if the mystery coolant leak is solved.

Cool, good to hear.