Ry

First off I own a 91 Runner 3.0. Was losing coolant to my number 6 cylinder a couple weeks back. It turns out that the water passageways between the head and intake were leaking and the coolant was dumping into the valley and into the cylinder. So the head gasket wasn't leaking but I figured since I got that far I may as well change them out too. At the same time I was installing Downey headers so pulling the heads off made it a breeze to get that stupid crossover pipe out.

Anyway, the trucks all back together and it runs great until it heats up. The temp guage just keeps climbing. So yesterday I replaced my water pump and thermostat and it changed nothing. My first question has to do with the head gaskets themselves. If any of you have changed them yourselves did you notice that some of the passageway holes in the gasket were not cut out? I noticed this with the new gaskets but since they (Victor-Reinz gaskets) came that way I figured that they were supposed to be like that.

When I let the engine heat up my top hose gets hot and I can feel pressure but my bottom hose stays cool to the touch. It's like the coolant is not circulating from top to bottom. I'm flushing my radiator out right now as we speak with some flush/detergent stuff.

I need ideas. It feels like I have eliminated all the possibilities, but apparantly I haven't. New pump, thermostat, rad. cap and now I've changed the coolant 3 times going on four.

Any comments are appreciated

Los Gatos?

If the gaskets are not IDENTICAL to stock, that would be the FIRST thing to check, not the last.

AgRunner06

I would have to agree. If you don't have holes in the gaskets where there should be holes than that is why you aren't flowing any coolant.

Ry

Well The old gaskets came out pretty beat up. But the new gaskets are that sintered metal with steel core plus one side of the gasket has a thin steel lining and everything that needed to be cut out had to be done through that steel. It was a high quality gasket set so I figured they had there stuff cut right. I was not about to take a drill and some tin snips to my new head gaskets if you know what I mean.

Otherwise I'm totally lost, there in no circulation at all. I'm going to try and remove my thermostat and see if I get any flow. Like I say the lower hose isn't even hot so I don't know if the therm would be able to open.

its2slo

i work on crappy hondas and certain ones are a beyauch to get the air out of the system. my theory is the air bubble cavitates around the propeller on the water pump and the pump cant pump the water anymore, so the top hose gets hot while the bottoms cold.

this can take alot of patients! follow the instructions in of your manual closely for the radiator filling procedure.

if i still have trouble i try it without a thermostat to see if that cures it, sometimes they open up slowly and not completely....

good luck, i hope/think its just air in your system.

Ry

So check this out guys! I pull out my Therm. Filler up and start the engine and Voila! I've got flow! Best part is my needle never even makes it to the half way point. I didn't even turn on my 'lectric fan. I took it for a spin still no upward movement in the temp.

This is great news. Atleast I am flowing coolant now meaning the holes in my gaskets were correct. .

So what gives with the therm? I had no way of accurately measuring the amount of water that came out, but it seemed like I poured in a lot more this time. Maybe large air pockets?

If that's the case, then how the hell can I get it back in without letting more air into te system?

This system NEEDS a bleeder valve. They make it so much easier.

Thanks for the replies guys!

Ryan

its2slo

loosen the clamp on the upper hose going into the engine. pull the hose back a little at an angle to open a small opening at the top only, fill it untill coolant comes out then retighten it and finish topping it off.. sorry thats my best description, anyways it will bleed off the air.

its2slo

forgot to mention, if the thermo is functioning properly (after ive checked it on the stove in a pan of water and a temp. guage) and i still have trouble, i drill the little hole on the thermostat flange a little bigger.

believe me it can take some patients, i feel your pain!!

you definately had air if you think you got more water in.

AgRunner06

This may seem trivial seeing as how you just did a head gasket job, but could the thermostat have been in upside down? I don't know if it is possible to do that on a Toyota, but I know you can do it on other makes.

AgRunner06

Oh yeah, congrats on figuring out the problem. At least you didn't have to tear the engine apart again.

williemon

My 3.0L had to have head work a while back. The shop could not get it to stop getting hot after they got it all back together. They thought the system had air and they could not get it burped. So they took it over to another shop where they sometimes farm work out to. They got it back and all seemed fine. It seemed to take an extra min to get up to temp, but once there, it held perfect temp all the way through the 95 degree summer. I got it back and ran it for about 4 months untill it started to turn cool outside. Then It would not get warm enough to allow the auto tranny to shift into overdrive. Ok I thought. Stuck thermostat. I get one from the dealer and it has a jiggle valve on it. Cool I thought. Pulled the lower hose and the thermostat and found the one in there had been cut so it had no plunger in it. It was just a big hole. By now Im mad as crap. I call the shop that did the work. They tell me to bring it all in and they would make it right. So I did. Turns out, long story short, they put the head gaskits on backwards (yea, they fit) and actually covered up a water passage. Once they got that all back right, put in a toyota thermostat, burped the cooling system (easy to do this time) all has been well since. So, you may very well have a covered cooling passage. This could also lead to hot spots in the head and cause a big problem later. I hate to tell you this, but you may have to pull the heads again. Use a new set of gaskits and new head bolts. Both are a one time use item. Believe me, I know, and so does the shop that did the work. Credit to the shop though, they made it RIGHT for me. Yea, maybe they goofed, but they did not charge me one cent more to totally redo everything. Later.

I forgot to mention, there IS a bolt or sensor on top of the engine thats at the top most part of the engine and extends into the coolant passage. As a trick to bleeding, this can be pulled and the air pockets will escape through this hole. When you get a steady water stream, put this item back in. I dont know what it is, but I read on a board that "something" was there to aid in bleeding, and the toyota dealership I consulted with says they have a little trick to it, and the shop that did my work said they even tried that too the first time. (the first time was actually the cooling passage blocked that was the problem.) Later.