is this a BHG?

[NiGMa]

I've got some interesting data for yas.

I've been trying to solve an overheating problem and I noticed that after a drive, even a short one, I have air coming out of my coolant overflow container hose, not the one on the outside but the one in the container. After a drive I pop the hood and I can see the surface of the coolant moving, so I take the cap off and only pull it out enough for me to see the coolant and I can see bubbles coming out of the hose. Its a pretty constant stream.

I didn't think there was supposed to be any air in the cooling system?

I thought I might have a leak in the heater circuit that could be letting air in. And I dont know if my heater VSV is working 100% so air could be getting in even with the valve closed. So yesterday I blocked each end off, so I dont have the heater circuit to cause symptoms. But after doing this I still have air bubbles coming out of the hose in the coolant overflow container. ???

Do I have another leak in a hose somewhere?

Do any of your cars have the same behaviour with the overflow container?

Thanks a heap guys! =)

NiGMa

 

[supramacist]

How does the gasket on the radiator cap look?
All in one piece..., or missing pieces.

 

[johnathan1]

A leaking hose doesn't let air IN...it leaks coolant, which has to be replaced by something...yep...air. Also, if you have that much air in your system, but no visible leaks, I would vote BHG.

Remember, the cylinder is under lots of pressure...when the headgasket leaks, that pressure (exhaust) is forced into the cooling system...Do a block test.

 

[NiGMa]

How does the gasket on the radiator cap look?
All in one piece..., or missing pieces.

I dunno, I replaced it a few weeks ago, its nice and new.

I also put in a new genuine thermostat last week.

A leaking hose doesn't let air IN...it leaks coolant, which has to be replaced by something...yep...air. Also, if you have that much air in your system, but no visible leaks, I would vote BHG.

Remember, the cylinder is under lots of pressure...when the headgasket leaks, that pressure (exhaust) is forced into the cooling system...Do a block test.

Yes, I went to buy one of these tests but the price scared me off.

Can you guys tell me if your cars have the same behaviour with the overflow container? or can you check?

 

[johnathan1]

I don't know what you guys have in australia, but I can rent a bock tester here (from Autozone) for about $30...

And the behavior you described is NOT normal...the heater valve won't make the car overheat. Do you get hot air out of the vents when the heater is on? You should only replace the radiator cap with a Genuine Toyota cap, btw.

 

[NiGMa]

I don't know what you guys have in australia, but I can rent a bock tester here (from Autozone) for about $30...

And the behavior you described is NOT normal...the heater valve won't make the car overheat. Do you get hot air out of the vents when the heater is on? You should only replace the radiator cap with a Genuine Toyota cap, btw.

I will get a genuine radiator cap, I hope its got a Toyota logo on it :biglaugh:

I've never heard of renting a block tester, dont you pay for the liquid you use up? how could they rent it?

I did have hot air coming out when I had the heater circuit connected, but now that I dont, I obviously don't =)

I can't see how I can put a new head gasket in and then 2yrs later have a BHG when it has always been nicely maintained??

I hooked up an extra coolant bottle to catch any overflow as explained in this thread: http://www.supramania.com/forums/showthread.php?t=251

I will report back.


Thanks again guys.

 

[NiGMa]

WOOHOO!!

I got home popped the hood and the extra bottle I put there is full of coolant, so I guess some overflowed onto the road too..

Ok well that DEFINATELY confirms a BHG for me. such a shame.

So I've read around the place that people advise not to drive the car or start the engine once it is confirmed that you have a BHG, why is this?

It is my daily driver and I have no other way to get to work.

I need to find a good mechanic now I guess, any tips on this? Anyone from South East Queensland on this forum?

Also, give me some advice on what things I should do while getting a new Head Gasket, is a full rebuild much more money?

What type of HG should I get? I like sticking with Toyota.

How many times can an engine overheat before it starts warping the head? Would mine be warped and needing machining?

Thanks guys :icon_razz

 

[thelonerider]

Though the Toyota stock gasket is good (IMO of course), the main problem is with the head bolts (easy stretch) and the torque settings (way to low). ARP bolts or studs should replace the original Toyota bolts. If your mechanic (or you) rebuilt the engine but used all the original stock settings and parts, you were due for another BHG. Also, when changing the gasket, the head should be checked to see if it is still straight and the block needs to be cleaned of any old gasket, If you decide to go metal, then the block deck needs to be machined and there is a whole series of steps to prep

 

[supramacist]

Wich engine do you have in the car right now ?

You don't need to check anything on the head. It HAS to be machined. The block at minimum must be lapped. You want ARP hardware and ya..., you want a MHG.

You shouldn't run the engine after the bhg has been confirmed simply so you cause no more damage. If you had a hole torn into your chest with your heart exposed would you want to get up and give your' buddy a ride to work?

The head will warp when loosened from the block without a bhg. It shrinks and expands just like any other metal. The overheating is a symptom of bhg wich adds additional stress to the easily fatigued alluminum. Wich causes extended damage. Because normally by this time the hg has began sucking air somewhere and hasn't totally blown yet.

These are just opinions and there is a reason they are free.

 

[NiGMa]

Wich engine do you have in the car right now ?

You don't need to check anything on the head. It HAS to be machined. The block at minimum must be lapped. You want ARP hardware and ya..., you want a MHG.

You shouldn't run the engine after the bhg has been confirmed simply so you cause no more damage. If you had a hole torn into your chest with your heart exposed would you want to get up and give your' buddy a ride to work?

The head will warp when loosened from the block without a bhg. It shrinks and expands just like any other metal. The overheating is a symptom of bhg wich adds additional stress to the easily fatigued alluminum. Wich causes extended damage. Because normally by this time the hg has began sucking air somewhere and hasn't totally blown yet.

These are just opinions and there is a reason they are free.

In the car now is a Japanese import 7M-GE engine I put in two years ago with a mate, the place I bought it from said they put a new HG in it and some seals, timing belt, etc. But I guess they didn't torque it down to the right spec. Or I should have checked it myself continuously. How often do you guys retorque your head?

I am definately gonna get ARP head bolts then, no questions there, anyone recommend MHG or they all the same?

Thanks again for the tips guys, it may be free but its invaluable to me. hehe

 

[supramacist]

I bought an HKS stopper 2.mm MHG. It was around $320ish.
The HKS beaded is also metal. Good gaskets.
They are not all the same.

You can't trust JDM. You drove the engine for 2 years. It WAS torqued down or you wouldn't have seen but 1 oil change.

On a used engine a retorque can make or break you. Everyone says to retorque them but I am not sure anyone ever does. You have to pull the whole thing apart to get the cam covers clear and pulled off.

It's easier on an na than a turbo'd engine. The gte guys have a lot more to remove.

 

[Burntz]

You dont NEED to run a MHG. A composite with ARP studs and correct torque will and can work on a GTE up to 14-16 pounds of boost.

If its an NA, then i think the composite would be fine

Pull the head, get it machined, mic your block, but you shouldnt have to lap it. Replace the valve stem seals, all the hard to reach hoses, yadda yadda.

And you should be fine.

 

[supramacist]

Why would you not lap it burntz ??
Something has to be done to the block even with the toyota oem replacement. Wich, by the way agree with your theory there.

You make it sound like all he needs to do is scrape the old gasket off and slap a new one on. That's not right dude. That's a gamble.

 

[supramacist]

Short cuts KILL.

 

[johnathan1]

As long as the block deck is flat, and there isn't any major pitting...you don't need to machine the block for a composite...

Mine wasn't machined, and was in good shape, and my car has been running fine for over a year and a half...and i turned the boost up to 12psi a few months ago...and now my CT is dying...but no cooling problems LOL.

 

[supramacist]

Alright gents, my bad.

I wouldn't do it without doing the block but that's just me I guess.
I have an oem topline graphite replacement. I'd sell it cheap. it's 0.76mm.
Make me an offer and cover the shipping.

 

[NiGMa]

I didn't have a BHG!

look at the pictures in this thread: http://www.supramania.com/forums/showthread.php?t=48471&page=7

 

[supramacist]

Chances are some of the seal was broken and hadn't gone out yet.

I'd like to see what your block looks like when you get the hg removed.

 

[NiGMa]

Chances are some of the seal was broken and hadn't gone out yet.

I'd like to see what your block looks like when you get the hg removed.

you can, its in the photos, you didn't see them?