shooting coolant out of reservoir/defunct heater
 

After replacing my blown headgasket, car ran perfect for about a week. Then I noticed coolant would shoot out of the reservoir, so I first thought it was trapped air, so I parked it on a steep hill and burped it. Stopped shooting coolant out of the reservoir for about a day or two. Then it started again, so I thought air was getting in through somewhere. Replaced the cap, and it stopped for a few weeks until now. I went to go burp it again only now I noticed that the heater doesn't work (because I never use it here in San Diego)! I don't think its the heater core since I don't have any coolant leaks (inside or out). I think its air getting in through somewhere. Unless its a bad thermostat, but I it doesn't overheat (could it be stuck open?).

What kind of HG did you use? Metal, OEM toyota, aftermarket fiber type? Did you surface the head? Did you use ARP bolts/studs? What did you torque the bolts too?

If you didn't surface the head, and/or if you used an aftermarket "stock" fiber style gasket, it may well be blown again. Same if you didn't up the torque to 85lb/ft.

Even the OEM Toyota HG won't hold much past stock boost on a properly prepared head and block.

Not a turbo...
 

Everything was machined, I used a Felpro aftermarket headgasket. I don't get why the bhg-like symptoms didn't appear until now (it was replaced back in Oct.). Its an N/A, so I used the original bolts. I think 85 ft*lb (not ft/lb!) is too much for the stock bolts. I told my mechanic to torque it to 70 ft*lb as recommended, but even if he did use the factory specs I don't think it would blow again after 800 miles (it took 125k to blow the first time!).

It's also strange that I'm not getting the waterfall sound behind the dash when cold. Makes me wonder if there is indeed trapped air. Could it be a coincidence that both radiator caps crapped out (one is a Toyota the other one is an aftermarket, but neither new)?

I know the defunct heater is related. Any ideas?

if you have trapped air in your system it would suck fluid from the overflow, the only way its going to shoot fluid out is if something is expelling out of the engine into the cooling system, or if the coolant gets hot enough to boil. Sounds like exhaust gasses in the cooling system. It could be anything from a defective gasket to a mistake by the installer. Get a block tester kit from napa and check for combustion gasses in the cooling system.

Bad Cap. No O-Ring! ;) Gotcha, not a turbo. Still high compression, just by piston design instead of forced induction. And machining of surfaces makes squish area smaller, which increases cylinder pressure (unless compensated by thicker gasket).

You could be onto something, though. I don't like aftermarket rad caps. New OEM Toyota has been the only thing that can hold the pressure when mine gets hot. Cheap fix to test the theory ~$10 at magauto.com, ~$15 at local dealer.

Same with the combustion gas test kit like CyFi6 mentioned. Cheap but effective test.

You could also have a good shop pressure test the system to test the cap/HG.

You say you replaced the head gasket. Did you pull the motor? Rebuild it? Did you disassemble the block, too? Because I don't know of any way to surface the block without pulling it out of the car and taking it apart completely.

I've done half a dozen Supra HG's, turbo's and N/A's. Every one had grooves worn into the block/head mating surface from the previous HG. How deeply grooved and corroded seemed to depend on if and how long the gasket was leaking prior to disassembly.

Iv'e done mine three times now, two times wrong. Once with OEM gaskets, no machine work, just cleaned extremely well, lasted a few months. Next was Titan MHG and ARP bolts with fully surfaced and lapped head only. I just cleaned the block again. That lasted until I went past 12psi boost. Then I lived with a mild BHG for 2 more years. Waterfalls and gurgling streams, ahhh....the memories! Good thing about the MHG's- even if they leak a little, they don't deform or deteriorate nearly as fast as the fiber style (OEM, FelPro, RockAuto, etc.).

I just finished a complete rebuild, fully machined and lapped surfaces, ARP studs, no leaks, no drips, no errors, @ 16psi so far.

I sure hope yours is just a bad cap! But if, heaven forbid, it's another BHG, go MHG w/ARP. It's money well spent.

http://i17.photobucket.com/albums/b5...iff/agreed.gif I couldn’t agree with you more, well said tsupranami.

heater?
 

yes, the engine was pulled. I'll do a compression test.

But what about the non-working heater?

This is really stupid but just my two cents. I took my res. out once and cleaned it good even replaced the rubber tubing and scrubbed the cap. I accidentally reversed the cap which has the two nozzles so instead of going into the res tank it would shoot out all over the place. Switched the hoses and worked fine.

that prolly wont help lol but im just saying.

Engine pulled. Check.

Was it a complete rebuild? Did you or the shop pull the crank & pistons? Are the new pistons stock? Oversized? Same compression ratio?

Was the block deck resurfaced? If so, how much was taken off? Was the head milled also? How much was taken off of it?

Does FelPro make HG's in different thicknesses?

No heat. Check.

No heat = no hot water in heater core *and/or* airflow blocked by debris in ventilation system.

No hot water in heater core = no water flow(control valve(s) not operating) *and/or* no water (air in system.)

No water flow = control valve(s) not operating(firewall hvac and/or thermostat) *and/or* heater control unit not operating (dash unit and/or vacuum actuator)

No water in heater core = incomplete fill and bleed *and/or* leak in cooling system

Incomplete fill and bleed - Did someone forget to have the heater on (heater core valve open) when the system was filled and bled?

The heater hose into the control valve at the back of the engine is higher than the cap. Trapped air here causes lots of problems on the 7M's. Sounds like you're aware of that, though.

Leak in cooling system = internal *and/or* external

No external leaks and all other systems are good (thermostat, radiator, cap, water pump, no collapsed hoses, etc.) = engine is overheating (abnormal timing / fueling) *and/or* there is an internal leak.

Internal leak = water in oil/oil in water *and/or* water in cylinder(s)

Water in oil/oil in water = Milkshake of Death

Water in cylinders = air in cooling system *and/or* cracked head (<1%), cracked block (<0.5%), BHG (98.5%).

Clear as Mud? Check. lol!

Hope that helps. Good luck! Keep us posted.

update
 

Well, I finally had some time to do a little more research, and it occurred to me that the thermostat could be stuck open. So I went to go start the car cold, and sure enough, there was coolant circulation in the upper hose right away. It's raining now, but when it stops I'll go to Toyota to get a new radiator cap and thermostat. I'll give you guys an update after I install them and purge it.

Yep, that could cause a problem. Let's hope that's it.

delayed!
 

I took off the thermostat housing, and there was no thermostat! Not only that, but the heater core was bypassed! My mechanic supposedly bypassed the heater core because the hose that goes into it was leaking and he couldn't find a replacement so it was a quick fix. At that it was done poorly, I'm more than sure air is getting in through there. So I go on to put in the thermostat, and the bottom bolt broke! So now I have to either drill it out or hammer a flathead screwdriver in to take it out (if any of you have done this before, please let me know how to go about it. I also bought a bolt extractor in case the hammering doesn't work).

I didn't have time to work on it until today, but I was delayed even more because the douchebags at Auto Zone and Kragen don't know how to find that hose without matching it, and I don't have the hose to match it. Does anyone know the diameter size and proper name for it? There's a good picture of it in the BHG repair sticky. The hose goes into the firewall on the driver's side.

Since were talking about radiators and coolant I have a question:

I have one of those pressure release radiator caps, and after a trip to class or home it kinda fizzes out where the release tab meets the metal cap (hard to describe) like someone has a straw blowing bubbles? I bought a new cap yesterday and it still does it. Any clues?

Thanks

I usually use a dremel with a cutting disk to cut a slot into the bolt end big enough for a flathead. You can also replace the entire thermostat housing if you can't get the broken bolt out, as it bolts to the block with three bolts (two studs/1 bolt.)

As for the heater hose, it's a Supra. Which means that normal auto parts stores don't carry most parts for it (including almost all the molded hoses except the upper and lower radiator hoses). I believe the heater hose will be Dealer or junkyard only. Maybe someone is making them now, but for the past ten years, whenever I go to Schucks, NAPA, or the like, they have almost nothing available that is Supra specific, in stock or special order. That's why my dealer gives me wholesale pricing, since I order parts for mine and several friends Supras on a regular basis.

It's just part of life with such a limited production car. Toyota didn't sell many Supras (relative to their other models) so most parts stores do not stock any Supra-specific parts, and if available at all, they usually have to order them.

Spudz - Supras weren't designed to use valved pressure relief caps (the one's with the little levers to relieve pressure). Get an OEM one from the Dealer, assuming the radiator is stock or OEM replacement. Fluidyne radiators work best with Fluidyne rad caps, etc.. If that doesn't work, there are probably other problems with your cooling system.

Oh I see. I did not know that, the car came with one when I bought it. Appreciate the help.

There are many different rad caps for the Supra, even more if you include the non-Toyota stock rads. Some caps are very similar in overall size but vary in depth. I made a few drawings of the two different types I have owned with the Toyota part #`s. Ignore the words Halfords and Nissens they only apply to the UK. Just look at the dimensions and the Toyota part #`s. You may have the wrong rad cap ?
http://i17.photobucket.com/albums/b5.../NewRadCap.jpg

http://i17.photobucket.com/albums/b5.../OldRadCap.jpg

where does this hose go?
 

Ok, so I finally got that heater hose I needed. But now I don't know where the bottom hose in the picture goes into. The one on the top obviously goes into the firewall, but I cant see where the one below it goes into, and it doesn't show in the diagram I got from the dealer. I think its just to bypass (because I don't ever remember it going anywhere on the top), but I just want to make sure.



http://i30.photobucket.com/albums/c3...rhosesupra.jpg

Does this help ? This is a left-hand drive Supra as in the US.

http://i17.photobucket.com/albums/b56/cirgriff/AH.jpg

The upper hose thats plugged with a spark plug is the heater hose on the left side of the diagram (into the firewall). The lower hose (also plugged) is what I don't know about. It's some sort of bypass hose, but where does that plugged end go to?

If you're talking about that little red piece (lowest red part on the left side of the diagram) it is a cap, and goes nowhere. On right hand drive cars, the plug moves to the other side of that rail.

This is the Right-Hand Drive Supra (UK) Steering wheel on the right.

http://i17.photobucket.com/albums/b5...LVEHOSESUK.jpg

I circled the hose that I'm referring to.

http://i30.photobucket.com/albums/c3...hosesupra2.jpg

On the two Supra's I've had there has been a little cap on the tip of the metal pipe. Your hose goes nowhere (it's basically just a bigger cap), as the pipe it comes off of is designed to work on both right hand drive and left hand drive vehicles. You can see this in the 2 diagrams that BillUK provided.

Head
 

Is there a difference in the turbo head and the non-turbo head, or are they interchangeable.:dunno:

update
 

Ok, so I got the broken bolt out, and I'm putting everything back together, only I can't get to the heater core outlet hose I need to replace! I tried getting around the EGR, but I have no choice but to remove it. Only neither the Haynes manual nor TSRM explain how to remove it. Where are the bolts I need to take out to remove the EGR valve?

nevermind, I found a diagram. :crazy2: