QuickPaws

Well... as some of you might have remembered... I stated a while back that I would be driving cross country with the Runner.....

Right away I started having problems.... I'm pretty sure that it's a thermostat issue.. I think. I'm not getting any heat off my heater when I turn it on, even though the truck is almost pegged to the redline for temp.

Secondly, I blew a hose. It's coming off the heater core hoses, but I can't tell what the hose is, and I can't find it in the FSM. I'm attaching pictures. Like the last picture post I did, the red arrows point at each other. The firewall is at the top of the picture, and the arrow points down towards the ground in pic 1. Pic 2 points in the direction of point 1.

I can't drive the truck anymore than maybe 5 miles before I start to get too hot to drive. I'm towing a 5x8 Uhaul, and I suspect I might have too much.. but I still don't think it should be heating up like this.... so... as it sits, it took me 34 hours to get from Phoenix, AZ, to Albuquerque NM.

I is stranded here, but at a friends house. I'll be getting rid of a ton more stuff from the trailer to lighten the load even more.....

So, here's the pics.

The area circled in red is the area that has the hole blowing coolant and water out.



The second pic is just following the hose, where it appears to be a special connection to a metal pipe, rather than a rubber hose.



Please.... help.

For the record, I have never let it get into the red zone. Only to the top end of 'normal'

1990mudslut

bugs1961

When the heater won't put out hot air it means that hot coolant isn't circulating. First check the level of coolant in the overflow tank and then in the radiator when the engine is cool. The thermostat won't prevent the coolant from circulating through the engine and the heater, even if it's stuck. It just prevents it from going to the radiator for cooling. It may well be bad and I'd change it with an OEM one if it hasn't been done recently.

Change the old hoses while your changing the thermostat.

Be sure the system if full with good 50/50 antifreeze and distilled water.

If the coolant gets low then there will be air pockets in the system that can prevent coolant from flowing and can give inaccurate readings on the temp gauge.

I live in Albuquerque and would be happy to help. I am out of town but will get back early Wednesday morning. After getting some sleep, I could give you a hand Wednesday afternoon. PM me if you're interested.

Take care and good luck,
Bugs

QuickPaws

See... this is the problem. I know something is wrong, because it will boil over out of the reserve tank. The heater USED to blow hot air at the beginning of this trip on Saturday night. ( @ 1230 AM ) And as I progressed through Flagstaff AZ, it was still working... that's how I limped along to ABQ. The hose in the picture blew on the I-25, three quarters of a mile from the San Mateo Blvd exit. ( literally like 5 miles from where I needed to be )

Problem is I also now have a blown hose, and no idea what the hose is.

You said that the t-stat won't prevent Coolant flow through the engine... is that true even if the t-stat is stuck closed?

bugs1961

The thermostat has a bypass that allows coolant to circulate around inside a cold engine as it warms up, including to the heater. On a cold day you can start to feel heat long before the thermostat opens and the radiator hoses get warm. This is the bypass coolant circulating in the engine. I've attached a picture from the FSM that talks about it. A heater that was putting out heat and stops indicates a very low coolant level and the temp gauge can't be trusted.

Take a look at the coolant level in the radiator after it cools down and top it off if needed. Then check if the heater starts working again.

I can't tell for sure from the picture but that looks like the hose that goes to the throttle body for the IAC system. Follow the hose/pipe and see if it leads to the throttle body.

QuickPaws

From what I can tell, the level def. drops in the rad when it's hot and starts to go to overheat. However, I stayed in Gallup last night @ a Motel 6, and from what I can tell there was no additional coolant missing other than what was missing to begin with when I had pulled over to let the truck cool down before finishing the route to Gallup ( I had been up for about 32 hours at that point, and needed to stop.

From what I can tell, NO coolant is getting to the heater core anymore. Sometimes I can get just a little heat out, but it usually goes away pretty quick.

Also, no white smoke or other odd signs from the exhaust, no exhaust smell in the coolant either. The rad only smells like water and... well.. coolant. Same for the over flow.

I basically drove from Phx, to ABQ pulling over every 5 miles or so to sit for 20 minutes and add water until I got out of Flagstaff. ( once in Flag, I was able to go for 30 miles once, and today I got a 60 mile drive out of it before I had to stop on the I 40 ) Though, I got that high because I would turn the truck off and coast down the hills in the break down lane, and then start it up again and drive up the next set of hills, and repeat the process.

Also, I'm a complete moron most of the time with vehicles. IAC is what? and I'll check for a TB image to see if I can match it up.

***EDIT***

From what I can tell from Google Images, this line is not connected to the TB. .. :-/

bugs1961

It's really important that the cooling system is totally full and all the air is burped out in order for it to function properly. If the radiator is a little low you'll have problems.

First replace the thermostat and the blown hose. Depending on which hose it is, you can use 5/8" heater hose or 1/4" heater hose available at Autozone, etc.

Set the heater control to full hot to allow the air in the heater to be pushed out by coolant. Slowly fill the radiator until it comes out the top and won't take any more after a couple of minutes. Run the engine with the radiator cap off initially. The air in the system will "burp" out after the thermostat opens and as it does, keep filling the radiator. Squeezing the upper radiator hose several times during this process will cause a surge of coolant into the engine and can help force air pockets out.

When you don't get any more air out, put the cap back on and allow the engine to heat up. Fill the overflow tank to the full line. You should now get good heat and stable engine temp.

It is critical that all the air is removed for the system to work!

After the engine cools following the first warm-up, it is normal for the overflow tank to be low. Keep checking it and refilling it to the "full" line (about half full) for the first couple of times the engine is warmed up and cooled down.

Hopefully you'll be back on the road again soon,
Bugs

bugs1961

The IAC is idle air control and uses water circulating through a valve in the throttle body to control the extra air needed to increase the idle on a cold engine. With cold coolant the valve is open and the idle is higher. As the coolant warms up, the valve closes reducing the idle speed. It uses a 1/4" heater hose.

I have to check out for now and will check back tomorrow afternoon with any luck. Take care and good luck,
Bugs

QuickPaws

in that second picture inside the circled section, the hose changes from that rubber heater hose, to a steel(?) hose. The compression fitting style thing over the rubber to steel section looks kinda like a cotter pin wrapped up in a compression fitting... but it's not a compression fitting.

Just to clarify something. Water should flow OUT of the top of the block ( through the upper hose, into the rad, right? )

bugs1961

Yes, that is correct. The cotter pin thing is one style of OEM hose clamp and can be replaced with a regular screw type clamp.

yoterr

did you fix it?? if not your heater core passages might be all clogged up, you can try louping the houses to bypass the heater core and later on backflush the entire system...

QuickPaws

No fix yet, I'll prolly start working on it tomorrow.

I was thinking that about the heater core being plugged up, but I don't think that would case the slow overheat would it?

QuickPaws

Awesome. You just made my night. I'm friggan stoked that I can just use a different clamp.

I'll prolly pick up with I need tomorrow, and work on it. My friend wants us to stay until Wednesday, or Wednesday night.... And I still need to offload some more crap from the trailer... I think I'm lugging around close to 10k ( including the weight of the truck, plus 6 dogs, and 3 humans )

I'll keep you posted on everything. Thanks for all the insight and support, and if I need some extra help, I'll certainly PM ya about it.

Thanks again

QuickPaws

Ha.... was just thinking before I passed out for the night...

I didn't see any reason to use it, but should I be using any RTV on that t-stat housing? To me, and to the FSM, it looks like it's just the gasket and the bolts that keep it sealed? I used some high temp RTV ( 650 degrees stuff ) on the outlet, and figured it would be the same down below, but can't find anything that says to use a sealant.

Thanks ahead of time, and again for the help.

bugs1961

I got a chance to check this thread before going to work today. No don't use RTV on the thermostat housing--it uses a rubber o-ring. Just clean it up as well as you can and put a new o-ring around the tstat outside edge. The o-ring has a groove around the inside that fits over the outside edge of the tstat. I highly recommend an OEM thermostat and o-ring because they are much better than any aftermarket one and will last a long time without giving any trouble.

Be sure the "jiggle valve" is at the top when you install the tstat.

Take care,
Bugs

QuickPaws

Alright. Awesome.

The oem that I'm picking up is about 9 bucks..., the gasket is 2. I'm on a tight budget, but it says it's oem, so I figured that was the best thing to do.

Thanks for checking in. Have a good day. I'll update on whether or not it resolved the issue.

QuickPaws

Alright... so I started the work today on things, and I found another blown hose.... one that might have been the problem to begin with... but I had never seen anything leaking from the truck. I'll attach pictures again.


The first picture is a 2nd hose attached right near the t-stat housing. Once again, the area in red is the section that is leaking, and the arrows point towards each other.




The second picture is the other end of the hose that ends at the round device on the side of the engine. I don't see either of them listed in the FSM.




Thanks ahead of time!

TNRabbit

That's the oil cooler; it is standard on models with the towing package. That hose will run about $11 from a run-of-the-mill parts place to as much as $28 from the dealer. If you're overheating this much, it does NOT bode well for the health of your engine! How hot is it getting?

RMA

These hoses go to your rear heater core

Not all thermostats have this by pass hole I think only the dealer ones do .

This is your oil cooler cooled by the water from before the thermostat.


Dude just remove the thermostat for now all your old hoses are blowing because of the thermostat is bad, it looks like only the hoses on the engine side of the thermostat are blowing when it gets to hot .

Remove the thermostat you could run like that , your in a super hot place anyway.

QuickPaws

I always turned if off when it hit the top part of the white -normal- temp range. I never let it go red, then I would coast for a little while to help it get hot air out, and then sit for a bit. Always cooled down to under normal in about 15 minutes.