Cooling issue

[supraken]

Ok so my supra started doing this new thing and i was hoping someone would know what was up. whenever i have been driving the car and i turn it off i will get out and coolant will spit out of the overflow hose then in a week to a week and a half the bird cage will light up to tell me its low. What is making this happen, i already installed a new thermostat and it is still doing it. Any suggestions???

 

[87tomanymods]

try a new rad cap

 

[CyFi6]

Get a block tester kit from napa and test for combustion gases in your coolant. Test your cap before just replacing it.

 

[supraken]

I tried a new rad cap and its still doing it :bigun2:
I will get a tester and test for exhaust gases sometime in the next few days.

 

[Kckazdude]

BHG thread in 5,4.......
Not trying to be an ass but if you have a new radiator cap and it has been doin this for more than a couple of days. You have a blown HG on cylinder 6 for sure.

 

[supraken]

BHG thread in 5,4.......
Not trying to be an ass but if you have a new radiator cap and it has been doin this for more than a couple of days. You have a blown HG on cylinder 6 for sure.

wow you nailed it, it blew bad today:aigo: im getting it towed home now, im going to attempt the worlds fastest BHG job on a mkIII:1zhelp:. Ive ordered a felpro gasket kit and ARP head studs, hopefully that will do the trick, whats the fastest anyone has done a BHG, just out of curiosity?????

 

[CyFi6]

You can do it in a weekend easily depending on how in depth you are going, and assuming everything is in good condition and your machine shop will get the head back to you fast enough.

 

[supraken]

You can do it in a weekend easily depending on how in depth you are going, and assuming everything is in good condition and your machine shop will get the head back to you fast enough.

this may sound dumb, but ive never had a BHG before, what exactly do i need done at a machine shop?

 

[jgcable]

this may sound dumb, but ive never had a BHG before, what exactly do i need done at a machine shop?

The head has to be checked for straightness. If it isn't perfectly straight they have to plain it (or deck it). This is an extremely important part of doing a BHG correctly. Make sure you torque the head down in the correct sequence using the proper torque specs (around 73ft/lb if I recall)
You will also need to retorque the head after around 5-10 heat cycles. This is also VERY IMPORTANT.
You will need to remove the waterpump so you might as well get a new one. I also did the timing belt, the fuel injector cushions and o-rings. I used copper spray on both sides of my gasket. keep in mind.. you really only get one shot to place the head on correctly so get it right the first time. '
When I took my head to the machine shop I had to completely disassemble it before they could straighten it. Because of this.. I also installed new valve stem seals. If you need to dissassemble the head you will need a special valve spring compression tool. I had to order mine. A BHG is a pretty big job if you have never done it before.
The crank pulley is EXTREMELY hard to get off. I used a 2' breaker bar and barely was able to get it. You will need a good torque wrench too.
You will not be able to tell if the head is straight using a straight edge. Trust me... you need to bring it to a machine shop. They charged me $100.00 to do it. I dropped it off in the morning and picked it up in the early afternoon.
Good luck and search this sight for tips. There are tons of them.

 

[supraken]

The head has to be checked for straightness. If it isn't perfectly straight they have to plain it (or deck it). This is an extremely important part of doing a BHG correctly. Make sure you torque the head down in the correct sequence using the proper torque specs (around 73ft/lb if I recall)
You will also need to retorque the head after around 5-10 heat cycles. This is also VERY IMPORTANT.
You will need to remove the waterpump so you might as well get a new one. I also did the timing belt, the fuel injector cushions and o-rings. I used copper spray on both sides of my gasket. keep in mind.. you really only get one shot to place the head on correctly so get it right the first time. '
When I took my head to the machine shop I had to completely disassemble it before they could straighten it. Because of this.. I also installed new valve stem seals. If you need to dissassemble the head you will need a special valve spring compression tool. I had to order mine. A BHG is a pretty big job if you have never done it before.
The crank pulley is EXTREMELY hard to get off. I used a 2' breaker bar and barely was able to get it. You will need a good torque wrench too.
You will not be able to tell if the head is straight using a straight edge. Trust me... you need to bring it to a machine shop. They charged me $100.00 to do it. I dropped it off in the morning and picked it up in the early afternoon.
Good luck and search this sight for tips. There are tons of them.

I just rebuilt this motor 6,000 miles ago and had the had the head and block done at a shop bored it 50 over new pistons, rings, valve seal etc. he leveled the matting surface of the block, also tested for cracks in both and they are both good. should i do it agian?

 

[supraken]

also im going to use ARP head studs, is it still necessary to re-torque after 5-10 heat cycles???

 

[Rennat]

yes, you should.

but you should figure out why it blew... either bad machining, bad cooling system. ect... somthing caused this to happen. especially with just 6k on the motor.

and you dont need to replace the water pump when you do a BHG...

just a side note about the studs though, you should REALLY clean the block holes out with a tap. there is normally tons of shit in there that even a hot tank wont get out.

 

[CyFi6]

Is it possible that you didn't have the deck machined with the rear timing cover bolted on?

 

[supraken]

Is it possible that you didn't have the deck machined with the rear timing cover bolted on?

this will make me sound stupid but i know exactly why it blew.

Mistakes:

1. I reused the original head bolts
2. I only torqued them to 58 ft. lbs (which was the spec i had)
3. I didn't re-torque after 5 -10 heat cycles

does that sound like a logical explanation? I think it does.
I hadn't discovered supramania until after i had put the engine and transmission back into the car and i was bolting on the intake and working on vacuum and such.

 

[jgcable]

this will make me sound stupid but i know exactly why it blew.

Mistakes:

1. I reused the original head bolts
2. I only torqued them to 58 ft. lbs (which was the spec i had)
3. I didn't re-torque after 5 -10 heat cycles

does that sound like a logical explanation? I think it does.
I hadn't discovered supramania until after i had put the engine and transmission back into the car and i was bolting on the intake and working on vacuum and such.

Yes it does. I would suggest having a machine shop look at the head. If it overheated it very possibly warped.
The original headbolts stretch if you use them over again. Your torque was wrong too.
Let me give you an example. I did my head over the summer. I replaced everything and followed all the pro's instructions here. After 10 heat cycles I retorqued the heads. Some of the bolts were off as much as 20 ft/lbs. Others were still at 73 ft/lbs. I used new Toyota head bolts and the lube to increase the torque accuracy I also chased the threads in the block prior to make sure they were perfectly clean. I have over 7000 miles on the car since with not even a hiccup. I replaced the waterpump and the timing belt, cam seals, valve stem seals, injector o-rings and cushions because they were all cheap parts and the car was all apart anyway.

 

[CyFi6]

I dont think that's a logical explanation considering the fact that to my knowledge im pretty sure they still toque them at 58 ft lbs at the dealership? Someone correct me if im wrong, is there a TSB somewhere? Also, the stock bolts are not torque to yield bolts, so they can be reused. Nowhere in the tsrm does it say you must re torque the head bolts after any number of heat cycles. Sure the way you did it might decrease the life of the head gasket compared to upping the torque, but it shouldn't have gone out that soon. Most supras lasted 80-90k miles before blowing the stock head gasket, and a lot never blew one at all.

 

[jetjock]

Agree. I reused them and never did a retorque. Don't believe in it. 56k miles later I'm still happy. Been working on cars all my life. Never done a retorque and never had a problem. Never had a factory manual that said I must. Never heard of a competent shop telling a customer to come back for one. Never heard of an auto maker requiring it be done on new cars either...

 

[jgcable]

I dont think that's a logical explanation considering the fact that to my knowledge im pretty sure they still toque them at 58 ft lbs at the dealership? Someone correct me if im wrong, is there a TSB somewhere? Also, the stock bolts are not torque to yield bolts, so they can be reused. Nowhere in the tsrm does it say you must re torque the head bolts after any number of heat cycles. Sure the way you did it might decrease the life of the head gasket compared to upping the torque, but it shouldn't have gone out that soon. Most supras lasted 80-90k miles before blowing the stock head gasket, and a lot never blew one at all.

I believe there is an addendem to the TSRM. I don't believe that Toyota ever had a factory recall. All the experts here highly recommend new head bolts or ARP studs. The addendem calls for a torque setting of 73ft/lbs I believe.
The retorque is only called out for head bolts. I am pretty sure that they don't suggest it if you use ARP studs. Most guys here do it anyway though.
I have heard many stories of cars having multiple BHG's until its done correctly. I think Toyota even acknowledged the fact that 58ft/lbs was improper. They came out with a new gasket at the same time.
You are correct, most N/A Supra's lasted 80-90K before blowing. Most of the Turbo's didn't last that long.

 

[jgcable]

Agree. I reused them and never did a retorque. Don't believe in it. 56k miles later I'm still happy. Been working on cars all my life. Never done a retorque and never had a problem. Never had a factory manual that said I must. Never heard of a competent shop telling a customer to come back for one. Never heard of an auto maker requiring it be done on new cars either...

I based my response on all the advise I got here on this forum. When I retorqued my head I found that a few of the bolts were almost 20 ft/lbs less. The guys here are so good that they even told me which bolts to look out for. This is the first time I ever did a retorque and I have been wrenching cars my entire life too. I came here as a Supra newbie a few years ago and I took all the advise I could get. There are great techs on this forum.

 

[supraken]

I Heard that you dont have to re-torque ARP head studs also. thats why i got them because the way that my new cams are made it is impossible to put the head bolts into to 2 of the holes(the second 2 from the front if i remember right) with out taking out the cams. that means to do a re-torque after heat cycles i would essentially have to tear it down to the head twice :aigo:. which im not to thrilled about but will do if absolutely necessary.