So so heat and lower rad hose not hot

[CJM]

Ok so this is interesting. Over the summer I replaced thermostat, both rad hoses, rad, waterpump and t-belt. Didnt notice till today when its like 9F outside, but the heat isnt pushing like it should it seems. Upper rad hose is hot but not so hot I cant hold onto it, lower is cold. I cleared out the cooling system and everything seemed fine this past summer, seemed like no clogs.

Bad t-stat? Water pump cant possibly be bad, I think I woulda overheated. Temp gauge is about a tick mark off from the middle, so I know its getting hot. Perhaps I have the wrong t-stat? It came with the t-belt kit from ebay from aircabin man (the kit everyone seems to buy) and was a denso/toyota part I recall.

Clogged heatercore? Bad waterpump, bad or wrong temp t-stat? Or is it just to damn cold? I stuck some cardboard in front of the rad but didnt seem like it did much.

The truck was fully warmed up just now when I checked all this.

Edited to add: Just removed the cap, damn coolant isnt even hot!!!!! Coolant didnt fly out either like you normally get..ugh I think the rad is clogged...brand freaking new!!!

[Seanz0rz]

Seems like you found your own problem (maybe), but I would also like to add this can be a problem with the valve to the heater core.

Valve on the firewall of my 4Runner (note: 1" bodylift makes this more accessible, on stock vehicles it sits lower in relation to the engine):
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/IMG_3083.jpg (http://s955.photobucket.com/user/hamiltonfabrication/media/IMG_3083.jpg.html)

Close up of the control cable:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/IMG_3084.jpg (http://s955.photobucket.com/user/hamiltonfabrication/media/IMG_3084.jpg.html)

Also with the mixer door on the HVAC box:
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/IMG_3086.jpg (http://s955.photobucket.com/user/hamiltonfabrication/media/IMG_3086.jpg.html)
http://i955.photobucket.com/albums/ae38/hamiltonfabrication/IMG_3087.jpg (http://s955.photobucket.com/user/hamiltonfabrication/media/IMG_3087.jpg.html)

There was a thread a while ago about not giving heat (or not giving cold with the AC). This should help future searches on the topic.




As for your problem, I don't know any good ways to fix a clogged radiator. Was this one OEM or aftermarket?

[CJM]

Rad was an aftermarket, but apparently a decent/good brand.

Im not sure if the rad so much is clogged or if the t-stat is bad, but I think Ill take it apart one day next week (no time this week) and see if I can check and or replace it. If it checks good then I assume the rad is the issue and Ill have to see about getting another one from perhaps a local supplier and not rock auto again.

I didnt have any issues with cooling/heating via the mixer i think, I have great AC so IDK for sure. This sucks with it being so cold too.

[Seanz0rz]

Check the PN on the thermostat and make sure it's not a low temp one, I know that has been an issue in the past.

[CJM]

Im gonna go buy one in the next few days and yank it all apart sunday. Hoping the heater core isnt clogged.

What temp do they spec for? I found in my FSM it said like 183 degrees it opens I think. I checked at 1st toyota parts and apparently there is only one for the 5vz? What is it about 180-190F?

[04 Rocko Taco]

We had an issue around here with cars not having much heat after new rads. Turned out the shop that was replacing them (before thay came to the shop where I worked for help) was taking a screwdriver and puching out the center of the thermostat to make sure that everything flowed fine, of course that ruined the t-stat forever.

Obviously this isnt your case as you installed it yourself. Crack the drain on the radiator, if it seems to drain relatively well, close it back up, and I would suspect t-stat before I went to clogged radiator, since it is new.

[Seanz0rz]

I've seen performance t-stats (even TRD I believe) that are 170F and people often complain of no heat.

[CJM]

Thanks for the info Chris and Sean! Ill give it a look see next few days, to dang cold right now and no time. :(

[4x4mike]

We had an issue around here with cars not having much heat after new rads. Turned out the shop that was replacing them (before thay came to the shop where I worked for help) was taking a screwdriver and puching out the center of the thermostat to make sure that everything flowed fine, of course that ruined the t-stat forever.




Another popular thing to do is to drill a hole in the flat part so that fluid could pass if the t-stat gets stuck. I guess the idea is that it will slowly overheat and give more of a warning. I had a t-stat on my first truck when I was 16. The thing overheated in a heartbeat. My second truck would have cooling problems and depending on the time of year, length of drive etc I would run no t-stat, high temp or low temp.

You can also test what you have on the stove. Put some water on with a thermometer in it and wait to see when it pops open.

Has your coolant level dropped any from when you replaced the radiator?

[CJM]

Nope coolant level hasnt dropped, I did have a leak problem where I traced it back to one of those stock spring loaded hose clamps was not sealing well. But I fixed that. Honestly thinking about it I didnt have any heat issues till it got REALLY cold these past few days.

Im wondering if by accident I messed up and bought some premix coolant and threw water in. I always buy the 100% stuff but it is possible. Wonder if got wate rin there and its freezing..which is really bad.. Gonna check it tomorrow in the am.

I dont think the heater core is bad, no water on the floor at all, no gurgling noises. The truck takes a good 15-20min of idling to warm up.

This sucks..

[Seanz0rz]

Maybe that is just a bit too much to ask from the heating system? Especially one that is nearly 20 years old.

[CJM]

Quite possible I guess it's about 15° warmer today about 25 outside instead of 9° and the heat works better maybe I was just expecting too much out of it I'm a try blocking off more the radiator maybe

[YotaFun]

What kind of coolant is in the system?
Is it something pre-mixed or you have to mix yourself?
I have Toyota red, and I tend to do more of a 60(coolant)/40(water) mix being that its usually cooler around here and I have had no heat issues even with the extreme cold, it still takes a good 20-25 min to warn up but thats just because its so cold.

I remember the last time I had the truck up north in this type of cold the heat wasn't as good and it was more a 50/50 mix (before I did the frame swap)

[CJM]

Walmart brand maybe I think, could be prestone I forget at this point and I recall its premixed. I do know its regular green coolant-nothing special. I think Im going to go ahead and see about the flow just for the heck of it since my friend agree to help me in a heated shop. What I think I will do is buy unmixed and then mix it myself at about 60/40.

Previously I had used this milk looking like coolant we had at the shop I worked for. It came premixed in a drum and IDK what it was but it worked really good.

[CJM]

Ok so more investigation so far leads me to think the t-stat is fine. and the following are observations...

-Its like 10f outside the heat works but isnt nearly as hot as Id think it could be. My chevy work truck with 280k makes better heat at these temps

-Warmer outside, like 20-25F the heat works fine. Blasting and hot.

-Truck still takes 15mins to warm up, probably just due to age.

-Upper rad hose when it was really cold out was not scalding hot liek you would think. I could easily grab it. Lower was ice cold. Havent had a chance to check when its warmer outside.

-Heater core hose going from truck into the valve seemed hot, but not scalding either the other day I checked when it was 10-15f outside. Hose past the valve seems cooler than the hose going in.

Im gonna hafta sit down and play with this for a day. Its really annoying. Temp gauge is near the middle, cardboard blocking about 80% of the rad has no effect. So either that valve is bad (can I nab one from another toyota truck at a yard?), something is clogged or it was just to damn cold.

[CJM]

Update:

The t-stat was bad it seems. We took off the water outlet pipe and it t-stat never closed. Once we replaced it, got better heat but still not great. There was an awful lot of air in the system as well that took us awhile to get out. Checked the hoses and before the heater core hoses werent that warm once they went into and out of the switcher valve, infact the one hose hotter that came from the block to the switcher but it got cold (about a 20-30F difference) once we fixed the t-stat it was much better. I got alot of air out it seems.

Still heat isnt that great. We decided that:
A). We think because the cat is leaking decently, it is possible the entire truck is running cooler than it should. Said buddy helping me has a dodge with a punched out cat, that sucker will not get up to temp all to well and the truck only has 60k on it. So it is indeed a possibility since my cat is leaking right at the flange and the exhaust is leaking.

B). The heater core is clogged possibly and we will try to blow it out.

[CJM]

Blew out the heater core today, some metal flakes and gunk came out-heat is way better. I ordered the heater control valve from advanced auto b/c the valve is cracked on one side a bit. Gonna replace the valve and then blow out the core a few times again.