Is it a BHG? Is it a DIY?

[Shytheed Dumas]

I believe I’m in for a head gasket job on my 1990 7MGTE. I just bought the car with a freshly installed 1990 JDM long block with about 36,000 miles. I immediately had a series of coolant leaks, which were easily taken care of by tightening a few hose clamps. Problem is I am still losing coolant with no apparent leaks. I have a gurgling sound behind the dash, and on occasion I have a poof of white smoke (steam?) when I start the engine cold. All things seemed to add up to a bhg – especially since I measured my coolant pH at 7.8 (far below the minimum of 8.3 I find throughout the internet). In addition to the pH, a new radiator was installed a few thousand miles ago and the coolant is already very dirty, which seems to indicate that exhaust has found its way into the coolant.

First question is whether this is definitely a bhg? Second is whether it is a good idea to try and tackle a head gasket replacement as a DIY project? From the various forums, it sounds like average Joes do it from time to time. A friend and I plan to tackle the project together. We have both gotten our hands dirty with fairly basic stuff like brakes, tie rod ends, EGR and idle air control valves, sensors, etc, and my friend has done a couple of water pumps and a valve cover gasket – all on other vehicles and all fairly basic. We are both chemists and able to handle technical detail very well. I feel like between Dylan’s How To’s, a Haynes manual, serious attention to detail, and a bunch of labeled zip lock bags for parts from the disassembly, we should be alright. I just don’t want to find out that it is impossible to get right without being a Master Mechanic. Please let me know what we might be getting ourselves into. Thanks.

 

[GrimJack]

Go for it, you'll be fine. I'm a Software Quality Assurance tech turned wrench, and haven't run into any insurmountable problems yet, I'm sure that there is just as much transferable knowledge from Chemistry.

As for whther it's a BHG, there is a thing called a block test that you can get done, it tests for the presense of exhaust gasses in the coolant. (Actually, it might be the same pH test that you mentioned, I'm not sure of the chemistry behind the test.) It's originally designed to see if there is a crack in your cylinder, but it works just as well for detecting blown head gaskets. You can usually get this test performed at most shops for only a few dollars, it's very fast.

Another good sign is coolant being pushed out of the overflow during driving - push the car hard for a minute, then stop, hop out, pop the hood and see if there is coolant or gas pushing out of the overflow tank.

Check your hose from the radiator to the overflow for leaks, and check the hose in the overflow for leaks. Either one can cause problems, the engine will push out extra coolant but pull in air, eventually leading to low coolant in the engine after many temp cycles. (This would cause the evil waterfall sound, which is caused by low coolant.)

Good luck and don't be afraid to post here for advice... a decent digital camera and some polite questions will get you far deeper into your engine that you ever thought possible!

 

[mkIIIman089]

don't forget the all important Toyota Repair manual. Follow it to the letter and all should be good!

http://cygnusx1.net/supra/library/TSRM/index.html

 

[GrimJack]

Oh - and buy some swiveling ratcheting wrenches - 10, 12, 14mm sizes at least.

The money you save doing it yourself is great, but you're going to have to reinvest some of that into tools.

 

[snotboy]

Im in the middle of the same project but ran into some other problems not related to the headgasket. Anyways my advice is have a digital camera and take lots of pictures or you will never figure out where everything goes, place all bolts back in the holes they came from after a part is removed if you cant, then place in the ziplock like you said. Make sure you have good tools I have stripped a few sockets. Tools I would make sure you have other than just sockets and wrenches, 10mm allen wrench socket for the head bolts, a breaker bar, some universal joints, not a tool but its not a bad idea to get some rust buster for your exhaust bolts (pb blaster from advanced auto parts works great). You also might as well replace all the gaskets and seal you can get to,and your timing belt.

also if you need help just ask someone can help.

 

[boost fiend]

and the one thing to remeber is that if you find that it is a bhg, it will mean its time to machine parts. might just want to pull out your wallet and set it asside because you wont be able to remeber the last time it was in your pocket! lol.


honestly though, if it is a bhg, it would probably be in your best intrest to have the head's deck surface and the blocks surface machined to make sure that its perfectly flat. and make a call and get your self a set of arp head bolts/studs. your choice. if i remeber correctly 80ft/lb is the torque you will want to have.

since everything is now apart, replace all hoses that have been there for xx amount of years. saves you hassle in the long run knowing you redid all of that before it went bad.

a digital camera and a good attatude will be your best friend here.
welcome to the group.:evil2:

 

[souprat]

what everyone said above is right on. replace everything you can get your hands on. get a whole lot of silicon hose and replace all the hoses, valve cover gaskets, t-belt. surface the head and maybe even to block. i found an extera fishing tackle box was perfect for keeping nuts and bolts sorted and in one place.

i think a hg is is definatly a job that you average person could take on successfully. the hg was the one of the first things i did on my car. i'm 19 and the only other expiriance i had working on cars was swaping out an exhaust or a pair of shocks. go for it. and if you get stuck you have the knowlege of all the members here at your disposal.

 

[americanjebus]

i was a 16 year old highschool student in algebra 1 and i didnt know how to CHANGE OIL and i still did it wiithout a hitch, without knowledge of websites like this.

take your head to the machine shop
get arps
minimum 75ft lbs tourque
make sure the block is really clean, and keep your progress clean,

you should really only need an 8,10,12, and 14 mm socket and wrench
screwdrivers
pliers
paint scraper
a torque wrench
full gasket set
and lots of paper towels

you have us to ask questions so dont sweat it, when your done you will be amazed at how much money you wasted with mechanics.

ps: DONT MIX YOUR VALVE SHIMS!!, keep them in the same spot they came from.

 

[againstdawall06]

I have a gurgling sound behind the dash, and on occasion I have a poof of white smoke (steam?)

i have that too, but my motor is pretty new. its more like a water falll behind my dash when it is cold. what is this? is it normal?

 

[whudafux]

i have that too, but my motor is pretty new. its more like a water falll behind my dash when it is cold. what is this? is it normal?

LOL!!!!! bhg. Another victim claimed.

 

[GrimJack]

i have that too, but my motor is pretty new. its more like a water falll behind my dash when it is cold. what is this? is it normal?

No, it's not normal. The sound is low coolant bubbling through your heater core, and it shouldn't happen.

BHG is the last thing to check for, however. First you burp your coolant by parking facing uphill, pull off the radiator cap (when the engine is cold) start the engine and let it idle for 15-20 minutes, monitoring the coolant level and pouring more in as needed.

Then you check for leaking coolant hoses.

Then you replace your radiator cap.

Then you do a block check - if this comes back positive, you start planning your BHG repair.

 

[Shytheed Dumas]

Wow, nothing but "Go for it!" from the group. And that's what I'm going to do. I will make sure I have a block check done this week and then starting buying parts and get my digital camera ready. Based on everybody's advice to replace everything as I do the job, I should say that the engine was installed a few thousand miles ago, and a bunch of parts are new, including the timing belt, lots of hoses, water & oil pumps, etc. The damn head gasket was also new, but I'm guessing that the mechanic who did the job might not have looked up the torque specs, but who knows? With that in mind, here are a few questions:

1. Should I invest in a MHG? 1.2mm, 1.5mm, 2.0mm?
2. Can you recommend a head gasket kit and the best place to get a decent price? Autozone has a standard head gasket kit available, but I'm a little worried about putting cheap parts into a job this big - I want a bulletproof head gasket when I'm done and never have to do it again.
3. If a kit isn't available, could somebody provide a complete list of parts that I need to get for the basic job?
4. Is it really necessary to drop the transmission (Dylan's How To) or is there a work around for this step?
4. Does anybody know of a decent machine shop in the Louisville, KY area who will do solid work and turn it around in short time for a good price?
5. How many hours for disassembly and reassembly would you expect for newbies?

Thanks everybody for the support! This is a great group, and the help is definitely appreciated. I think I can! I think I can!

 

[souprat]

1. if you are going to do a mhg you have to surface the block. that means pulling the entire motor out, dissasembaling the entire bottome end, machining it, reassembaly, and re-instalation. i figure by the time you have it al apart like that yoou might as well just rebuild the motor. there is nothing wrong with the stock hg, only the stock torque specs. a stock gasket with arp studs torqued to 80ft/lbs will serve most ppl just fine. what are your plans for the car? DD? or 5,000hp monster?

4. it depends if you are going to pull the motor out of the car or if you were going to just pull the heads off. you can pull the motor and trans out together, set the motor up on a stand and proceed to fix the hg. or you can leave motor and trans in the car and just pull the heads. up to you. get a TSRM from toyota, worth its weight in gold, a good deal at twice the price, just go get one.

5. it took me an embarassingly long time. but i was going to school and didnt have alot of time to work on it. pros can do it in like 8 hours. if i were to do it again it might take me like a week from start to finish. i work kinda slow.

 

[Joel W.]

Read everything you can find on bhg's, get a box of sandwhich baggies and a sharpie ink pen and bag and lable everything.(nuts and bolts) .take pictures, there are some step by step how to's in FAQ here that are invaluable for begginners...

i found a wall and set each part i took off in order down the wall, this makes it easier to go back together for reassembaly

take your time and do it right.. no worries..

 

[jmcboost]

What is a reasonable price to pay someone to get the head and block the way it needs to be for a MHG? Also when going to a shop, how do you know they can do the job right?

 

[GrimJack]

You have TWO number 4s.

1. Depends on your goals. If you want to keep it under 400 hp, and / or you don't mind pulling the head to replace gaskets, go OEM. If you want a bulletproof system, go MHG. The thickness of your MHG depends on how much material your machineshop takes off the block and head.
2. I'd suggest getting a few of the gaskets directly from toyota - intake, exhaust, turbo in & out, and using Toyota FIPG for the rest. Don't bother with a kit.
3. If your engine was just replaced, the list of parts could be rather different. Most of us pull the head and replace parts as required. For sure you will need the ones I mentioned above, many other hoses & seals should be replaced if they are no longer flexible.
4. It is easier to pull the engine & tranny as a whole, if you are going the MHG route.
4. Hopefullyl someone from the area will chime in, I'm about as far away as you can get from you while still living on the same continent.
5. With a dedicated team of 2 people working on it, I'd expect you can tear it out in a weekend - then you have a couple weeks to wait for the machine shop, you can clean parts during this time - then another weekend to put it back in.

Good luck!

 

[Joel W.]

maybe it should be called "bullet resistant" as the mhg seems to only delay the bhg if not tuned properly from whats been posted recently? just my thought..