my 87 Runner w/ a 22RE is overheating, and boiling the coolant on shutdown. the fan is running, upper and lower hoses seem to be clear, but the upper hose isn't hot, which the Hanes manual says is indicative of a thermostat being stuck closed.

so I plan on replacing the thermostat, with a new gasket, and using RVT sealant. also, there are a bunch of vaccuum and other lines running across the top of the thermostat housing. is it going to create any problems to diconnect any of those to access the thermostat?

anything else I should be considering with the thermostat replacement, before trying to look at the water pump or radiator?

Carefully label each vacuum line before removing (both ends) and document where they connect.
- http://www.4crawler.com/4x4/CheapTricks/index.shtml#TstatReplacement

get a paint marker an mark all your hoses BEFORE you disconnect them. Or take a pic for reference. My guess is your thermostat too BTW, or totally clogged journals, which is much less likely.

<img src="/forums/images/graemlins/scared.gif" alt="" /> OOPS <img src="/forums/images/graemlins/scared.gif" alt="" /> is right.....overheating this week and blown HG next week. Sorry to put the news to you that way but people have told me that I'm psychotic and can foresee the future <img src="/forums/images/graemlins/cheers.gif" alt="" />
I put my money on the radiator especially if it has high miles. Been there. Done it. ZUK

edit----trey....let me guess....it tends to overheat faster on the highway....going slow around town it's ok.

additional edit---haha! Yours is an 87 22RE.....so was mine with 211K on the radiator. The radiator was my issue but I let it overheat maybe 6 times before I figured it out so the HG went the following week. Lots of white smoke pouring out the exhaust.

$110.51 .......I believe I got mine from here....took only 3 days to get..... http://www.radiatorbarn.com/s7.asp?...ALL+MODELS&engine_size=L4%2C2.4L

so I just broke the bolt on the thermostat housing closest to the valve cover. what do I do now? and this is my daily...

and I'm sitting at 236k miles. Zuk, it's slightly cooler at speed, climbs faster sitting. I wouldn't be suprised at the radiator, but wanted to go the "easiest", cheapest route first. and it's stayed w/in the marked limits on the temp guage, to try to avoid the HG swap.

Overheating while stopped could be the fan clutch, test it to see:
- http://www.barneymc.com/toy_root/techneek/fan_clch.htm

If the broken bolt sticks out enough, try heating it up and see if you can grab it with some vice gribs. Otherwise drill and screw extractor.

Get the broken bolt out.....got any clear close-up pics of the break? Mcgyver might goop it up with Ultra-Blue RTV and tighten down the one good bolt and let it dry 24 hours. I once did a similar thing for a customer at Checkers in SLC,UT.....3 months later she came in to get something and told me it was still holding great.
Your symptom of a cool upper radiator hose and running slightly cooler at highway speeds points to a water flow issue of some sort. How's the tightness on the water-pump belt? Keep us updated.

didn't do anything with it yesterday, because I couldn't get an extractor. today me and a buddy broke the extractor, ran through a couple of drill bits getting that delt with, tapped a new fitting for a m10x1.25 bolt, got it sealed up, and am letting that cure tonight to see if that was what was needed. looks like the old thermostat wasn't opening fully when we played with it, once we got it out.

see how it goes tomorrow.

well, we seem to have fixed it. it's operating higher than it used to before the overheating, but staying just about halfway up the normal operating range of the gage. haven't driven it hard yet, just got it stablized with some easy driving near the house in case it wasn't fixed. so I think it's good.

when I was describing it before, as it was over heating, it would heat faster in slow or stop and go traffic, but would heat slower (but continuously) when up to some speed.