Head Gasket Replacement

[baadshah11]

Hi everyone.

So I bought a toyota supra and the owner who sold it to me ripped me off. He neglected to tell me that it had a blown head gasket. It was stupid of me to not get it checked by a mechanic but I did check the VIN of the vehicle and it had no accident history. Also the vehicle looked perfect. The body had no rust and there didn't appear to be any mechanical problems while driving. So I went ahead and bought it.

The second day after I bought it I realized that the car was really over heating and the coolant light popped up a couple of times. The exhaust also had a very sweet smell and would produce white smoke during initial start up. I quickly checked these forum to see what problem it was. I checked the oil cap but it didn't have any white stuff. The oil looked normal. I took a closer look at the engine and it seemed to be leaking between the head and the lower block. This was confirmed by the oil spots left on my driveway.

So what I did was send the car to my mechanic whom I told to change the head gasket. He ended up charging me more than a grand and all he did was replace a couple of hoses NOT the head gasket.

I don't wanna waste any more money unnecessarily so I'm planning on replacing the head gasket myself. I'm not a stranger to mechanical work. I did take a couple of automotive classes in high school however, this is the first time I will be doing such extensive repair on a car.

I just wanted to ask people for some advice. If you can give me any tips and point out important things and what to watch out for while doing this.

I bought a Haynes repair manual and will be following that. So far the most important piece of information I know is to torque the head bolts to 72 - 75 ft*lbs.

I will be buying an HKS metal head gasket and ARP studs. Are these the right ones?:

http://cgi.ebay.com/ebaymotors/ARP-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

http://cgi.ebay.com/ebaymotors/HKS-...r_Truck_Parts_Accessories?hash=item4149dcb89c

I don't want to make any more noob mistakes. Thank you and appreciate your help.

 

[Weeves]

To use a metal head gasket, you have to send the head and block in for machine work. The surfaces have to be completely smooth and flat.

75 ft-lbs is correct torque for head bolts, but ARP head studs require 80 ft-lbs when used with ARP moly lube.

Don't buy a MLS HG until you know your cylinder bore size and how much thickness was machined off the block and head. Then you choose a thickness to compensate. Stock thickness is 1.37mm.

 

[iskrem]

I think you should visit your mechanic and make him do the job for you.

 

[jdemara]

Im in vancouver as well.. I am curious as to which supra this is you're talking about? was it on craigslist?

 

[Kevin]

yes make your mechanic do it for you... if not take some kind of legal action.. because he said he'd do it.
anyway if you are gonna do it yourself and want to go mhg... you have to get your head to a machine shop and get it decked properly. then you find out how much material your machinist took off to figure out what SIZE head gasket to use in order to not change your compression ratio. There is a sticky somewhere that deals with head gasket selection.

you can probably get away with hand lapping your block but taking it out and to a machinist to do it is much safer. everything has got to be smoother then a baby's ass... metal head gaskets are not as forgiving as the stock type.

if you are not going for high horsepower then you could do with a stock head gasket. with arp studs.

if you take your block out, check out your rod bearings for corrosion because most likely you had some contaminated oil..

edit; Beat up the fool who sold it to you hahahaa

 

[grimreaper]

toss an oem hg back on there and call it a day. (assuming the surfaces are flat.) Stock one will handle just fine with stock/or decent tune with the right mods.

other wise pull the block and fork over the money to have everything surfaced (might as well rebuild the bottom end imho).

 

[wardog]

The Hks 1.2 mm is already too small for a decked head and block. The stock head gasket compressed is 1.3 mm plus you gotta add what ever was taken off from the head and block IF YOU DECIDE TO PULL THE BLOCK. Like GRIm said , you can clean the block and head and slap a stock one with arps. It will hold power levels close to 400 rwhp. There is a dyno of a 500rwhp car with stock head gasket and arps. Good luck with your decision and keep us posted..:beer:

 

[baadshah11]

Im in vancouver as well.. I am curious as to which supra this is you're talking about? was it on craigslist?

thanks a lot for the info guys. and yea it was a red 89 one on craiglist.

 

[Aliass]

How many hours would it take for a mechanic to change the headgasket anyway?

 

[SideWinderGX]

For a mechanic who has done headgaskets on various cars before, half a day. As much as I'd go back and raise all hell with the guy for jipping you that badly, I'd be wary about his work. So be prepared to possibly go back there again and raise more hell, or bring a competent friend to argue with the guy.

 

[jdemara]

how much was it? $4500?

 

[mjsn1]

After you fix the engine don't spend more money on it. as fast as you can sell it, and get your self another engine. because this engine will have more problems in the future.

 

[radiod]

After you fix the engine don't spend more money on it. as fast as you can sell it, and get your self another engine. because this engine will have more problems in the future.

Not true, in fact completely the opposite. You redo the engine properly and you'll have fewer problems with it in the future. That would be the whole point of rebuilding.

I would be going back to the mechanic personally. The book time on a head gasket replacement on a turbo Mk3 Supra is right around 14 hours (according to Mitchell On-Demand). Typical shop rate (at least in Abbotsford) is between $80-$100/hr, so you should have been able to almost get a complete head gasket job (minus parts) for what you're saying he charged you.

If you are looking at doing it yourself, there's lot's of resources on the site. People have posted picture instructions on what to take off in what order and tips/tricks for getting everything back together properly.

As for the block, they tend to be ok unless there was some major overheating issues. You CAN check it yourself with a feeler gauge and machinist's straight edge, but keep in mind that 0.001" can bee too much for an MHG to seal properly, and that's VERY easy to miss. Also you need to make sure that the surface is PERFECT, getting any remnants of debris, gasket, etc. off WITHOUT damaging the steel surface underneath. The little abbrasive discs you can use on a die grinder will leave little swirls in the metal and even that can be enough to cause the gasket to leak. So just be warned that you are taking risks not resurfacing the block, but it can be done (I did it successfully on my own engine).

If you do decide to pull the block, it will be worth your while to pull apart the bottom end and at the very least inspect your bearings and whatnot. If it's all out anyways, might as well spend the time to make sure it will give you years of enjoyment rather than a couple months before you hear knocking on the bottom end just because you neglected to inspect/replace your bearings.

Here's a couple of the resources I used:
Toyota MK3 Supra Service and Repair Manual: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/ (there are other useful sections on that site as well)
Suprarx7nuts' BHG Thread: http://www.supramania.com/forums/showthread.php?t=62881
Another pictoral HG Replacement: http://gallery.sanitylapse.com/v/supra/Head+Gasket+Dismantling+5-14-05/

Parts and supplies I bought for the job:
8L 5w30 cheap oil to keep the block/cylinders coated
5L 5w30 Synthetic for after the job was complete and verified that no oil leaks were present (don't use synthetic initially if you do your piston rings and need to break in the build)
Oil filter
2 x Comp Cams 975-12 valve springs
Cometic MLS head gasket
Felpro 7M GE/GTE head gasket kit
2 gallons Toyota Red coolant
4 cans of brake clean
1 can of gasket cleaner
1 can of penetrating fluid
1 bottle of fuel injector cleaner
Bulk 3/8" coolant line
Upper rad hose
Thermostat
Bulk 1/4" vacuum line
Shop rags

I think that's a pretty extensive list...but I might be missing a small thing or two.

 

[grimreaper]

After you fix the engine don't spend more money on it. as fast as you can sell it, and get your self another engine. because this engine will have more problems in the future.

You should refrain from posting in the tech section.

 

[baadshah11]

how much was it? $4500?

yea thats the one i think

 

[supramk3speed]

I have one question when it comes to using a stock gasket, i thought you want to make up the difference as to not change the compression ratio but if you use a stock gasket, well you can't.

 

[supramk3speed]

And of course i mean head gasket.

 

[Kevin]

I have one question when it comes to using a stock gasket, i thought you want to make up the difference as to not change the compression ratio but if you use a stock gasket, well you can't.

that is correct. stock hg was meant for stock head and block. if you mill them.. and decide to go stock gasket then you are gonna increase cr a little bit. shouldnt be tooo much of a problem. but if you are gonna mill the head and block... why not go with a mhg anyway.. only gonna cost a bit more.. and it will allow you to keep stock cr and give you peace of mind (if done correctly)