Overheating

[rnoswal]

I have had this POS for a couple of years now. The engine was overheating and blowing water out the overflow. I thought, blown head gasket. Well it was sort of, but mostly it was the eaten up head that wouldn't allow the head to seal properly. I also had another block bored because what I had needed rebuilding and I wanted a fresh engine.

The problem was that the cooling system would pressurize and blow the water out of the system and overheat! I tried a couple of heads from the junkyards but all of them had been eaten up pretty well and the gasket wouldn't seal. I bid on a realy nice head, got it in and checked it out and stuck it on. Well I was still getting the bubbles in the radiator coming out the cap hole. I finally pulled the head off the last time and found that the number 1 cylinder had some pitting and it looked like the water was seeping in there but also being pushed out when the engine was running.

I got my old block and had it bored then just transferred the parts to the just machined block. I built it, put it back in, connected everything, poured water in. I started it up and the bubbles are still there. They look like bubbles that might have a bit of exhaust gas in them. They just keep on coming out, never stopping. Eventually the system pressurizes and blows the water out and it overheats.

I got the radiator cleaned out and it has a new water pump. I just have been racking my brain trying to think of where and how these bubbles are getting in the system. It has to be something periferral, at least I think it does. I am ready to shoot it. I want to drive it so very bad, but I can't.The head is basically new, the block deck was milled flat I am getting the same problem with the engine setup as with the other. That is when I start it up. with the radiator cap off, I am getting bubble coming out of the cap hole. It never stops. the engine overheats after 20 minutes of idling and blows all the water out. Freeze plugs are sealed too. Somthing is forcing air into the system somewhere, but I am at a loss.

Any help would be very much appreciated. Suggestions, hints, even Miss Cleo. If you need more specifics, please ask.

Thanks
Russ Lawson

[suprra_girl]

well... it's 2am currently

i read your thread... i'm dumbfounded...

i'm sure i know why

but i can't think or answer right now LOL

i must be tired, but tomorrow i will answer

promise!! hehe

[suprra_girl]

well... i've been thinking about your problem all day....

about the most i can come up with is...

it's not bhg'd... more you have a split or leaking water hose which is sucking in air.. therefore constant bubbles?

have you burped the car?
are you sure it has a bhg?

have you done

• leakdown test
• compression check
• block check

let us know how you get on

[daiagaru2]

hello,it maybe a leaking hose this would more likely leak coolant than suck air in.is the waterpump actually pumping,even when you do replace a waterpump brand new there may be air in the pump preventing the water from ciculateing coolant thru the engine.sometimes a vacume pump is requred to get the air out.my other suggestion is that the thermostat is not functioning correctly preventing the flow of the coolant thru the waterpump,thus the system becomes preasurized and extremely hot and spitts the coolant thru the overflow and out into the overflow tank.if your rad is good you've covered all the other bases milling the block,milling the head at the same time making sure the surfaces are true and using brand new metal head gaskets .also,have you had these blocks magnafluxed along with the heads there may be a minute crack somewere causin this irritating endevor.thats all i got for now, i hope this helps.being as thorough as you sound i'd immagine you'll figure it out.if not i'll try to brainstorm a few fresh ideas.have a less frustating day,and don't let that crap defeat you.

[suprra_girl]

^ thanks for the additional suggestions heh

i should be the bhg expert considering i've killed 4 LOL (crappy locally made ones )

i think i've seen almost every symptom there is for bhgs... but the above really had me for a while lol

[daiagaru2]

man, the more i look at this post the more it seems like the block deck surface and head deck surface are not mating correctly,the reason i say this is because you say you see exhaust gas leaks ,you also say that it seems like water is getting into the block. check the valve seals,if this is okay then make sure the blocks deck surface is machined to factory specs and also that the head deck is machined to factory specs,then with a new metal head gasket slap that onry thing back together use arp fasteners.if you've done all this correctly then all you have to worry about is the stuff i mentioned to you in my previouse post.i'm not assuming that you haven't done this correctly, i just want to make sure you have the right information.i hope this helps, if it doesn't help then i deserve 900 lashes with a wet noodle.

[rnoswal]

Hmmmmmm...I sure do appreciate all the suggestions. I did not have the block magnafluxed. I have done work on other Toyotas and while I have seen the blocks leak on the outside from rust below a freeze plug or a stress crack, I have only seen the cylinder pitted just once where it was leaking coolant once and that was my last 7mge engine. The mating surfaces are flat and the guide pins are not too tall and the head bolts are not bottoming out. I feel good about that mating surface.

What I don't like is the way the waterpump impeller is turning. The fan is turning the correct way to pull air through the radiator, but the impeller seems to turn backwards from what I would think as normal. Most people mechanic friends I have asked about this say it looks like it should turn just the opposite from the way it is turning.

If you turn the waterpump over and look at it from the impeller side it turns counter clockwise as it should with the way the engine turns over, clockwise.........with me still?!?!?!?!....lol. Most mechanics think the impellers should turn with the leading upper edge first, cupping the watter and forcing it to move. Instead it looks like the back side of the impellers are pushing the water away. They are arced and this way looks like it causes cavitation when it spins and very little water movement. I looked at a bunch of water pumps for the car and that is the way they all look.........so, anyway it just seems weird.

Now I have an electric fan on the newly acid dipped radiator, but I didn't have a thermostat in it. Well there was one in it but hollowed out. Is this one of those cars that needs a thermostat to slow the water down through the radiator?

If I drive it around town for a little bit, it seems to run a normal temp, but as soon as I get it on the freeway, it overheats. Should there be a shroud under the car from the airdam to the front crossmember? Would that help more air go through the radiator at higher speeds and keep it cool?

I have never had a problem with overheating like this car. I really like it, but I am taking more and more drugs to help me not drive it off a cliff, well, into a swamp down here in Louisiana..........lol.

Thanks and sorry to be so long winded, my kids think I talk too much also..........sigh.

Russ

[daiagaru2]

try putting a 180 degree or 192 degree thermostat in,it's cheep and easy and worth a try.i'll bet at this rate that your thermostat set up is your problem,it will tops cost you 16.00 dollars and at most an hour of labor.without the thermostat the rad does not have time to cool the water .after all an easy fix is the best ,if it is possible.see if it's possible ,laters!

[Poodles]

Yes, there are airdams on the underside of the car, but the car has a grill that allows plenty of air through, but it's worth getting them to force the air where it's supposed to go. Yes, get a thermostat, it may help a lot on this. Also, I know that water constantly goes through the heater core, so there may be air trapped in there, I know my bro had problems on his car getting the system to release all the bubbles and fill with water after he changed the engine.

Also, change your radiator cap. It holds the pressure in the system, and is spring loaded to allow it to vent to the bottle, and they do wear out. I think your water pump is fine, if you've looked at a bunch and they're all teh same, it should be fine, plus I don't know of any years that had backwards rotation on the fan/pump.

Also, is your electric fan one with a fan shroud, if not, that could cause yu to overheat as it will just suck air from around the fan and not through the radiator.

I'm outta suggestions, but if you suspect it's the HG, do a compression and leakdown test and at least get that out of the way and make sure it's not that.

[daiagaru2]

and i grow even wiser,i love this place!