Head Gasket job (total noob) (2 Viewers)

[Jorgito]

Question: There are four connectors on the driver side of the head and actually Doug in his famous video is not talking about the connectors at all. What is the best time and way to disconnect those connectors ?

I think it is ECT sender, ECT cut, and ECT sensor

 

[baldilocks]

Jorge, you are correct about the sensors but there are also two knock sensors in the side of the block and each one has a wire connected to it.
I agree that the Toyota connects are a pain in the neck to deal with sometimes but I encourage you to remove the lower intake manifold so you can send it to the machine shop with the head for a good cleaning on the inside. This way, you will be able to thoroughly inspect the wiring harness too. I ended up installing a brand new harness in mine because it was pretty beat up and had three melted/bare wires at the egr valve tube.

 

[Jorgito]

My budget is tight, I simply can't afford changing every hose and do all "while you are there". I need to find some compromise. My goal is to have this vehicle go for 30k miles without breaking next year. All I have is about 3k dollars to do all PM before the trip next year.

 

[AJP]

Question: There are four connectors on the driver side of the head and actually Doug in his famous video is not talking about the connectors at all. What is the best time and way to disconnect those connectors ?

I think it is ECT sender, ECT cut, and ECT sensor

well you are going to have to undo the wiring to the sensors on the head .. before you take the head off. And I think now is a good time... just be very careful not to break any sensors by letting them be struck by the lower intake manifold when removing the manifold or the head. be careful not to snap any wiring connector tabs as well.


As for pulling the lower manifold out ... you cant do that without disconnecting the engine wiring harness from the ECU OR from all the sensors on the other end .. starting from the 02 sensors and working back ...drawing the wire back over the transmission etc etc and if you are very lucky you may be able to get the two plugs undone to the transmission - then the block sensors .... but IMO only ... dont bother. ALSO I believe that manipulating the harness through the lower manifold when you pull from the ECU may be why some guys have broken wires inside the harness. You can still wrap the harness where it sits around the EGR tube without taking it out of the manifold. And personally I wouldn't obsess about some surface carbon in the lower manifold ... those are VERY big holes ... and I doubt that the flow of air is going to be impeded enough to effect engine performance. You'd be farther head taking the time to lubricate your muffler bearings.

 

[Jorgito]

Jorge, you are correct about the sensors but there are also two knock sensors in the side of the block and each one has a wire connected to it.
I agree that the Toyota connects are a pain in the neck to deal with sometimes but I encourage you to remove the lower intake manifold so you can send it to the machine shop with the head for a good cleaning on the inside. This way, you will be able to thoroughly inspect the wiring harness too. I ended up installing a brand new harness in mine because it was pretty beat up and had three melted/bare wires at the egr valve tube.

Why do I need to disconnect the knock connectors, aren't they located on the block instead of the head ? Is it because when I pull the manifold to the side the cable can stretch and brake the connector ?

Jorge

 

[Jorgito]

This is what I found, going to see where these knock sensors are:

"something that is not mentioned much, but REMOVE the knock sensors!!! They are easily broken and when you take the intake manifold of, the bottom part does not come out of the engine bay cause it has the wirring harnes thru it, so it just get pulled back a bit and ends up sitting on the knock sensors.. and with just a litle bit of pressure,,,SNAP... the dealer raped me when i had to get new ones...."

Advice or warnings before replacing head gasket

 

[baldilocks]

This is what I found, going to see where these knock sensors are:

"something that is not mentioned much, but REMOVE the knock sensors!!! They are easily broken and when you take the intake manifold of, the bottom part does not come out of the engine bay cause it has the wirring harnes thru it, so it just get pulled back a bit and ends up sitting on the knock sensors.. and with just a litle bit of pressure,,,SNAP... the dealer raped me when i had to get new ones...."

Advice or warnings before replacing head gasket

Ths advice post is telling you that the poster ended up breaking the external portion of his knock sensors when the lower half of the manifold rested on them. You told us that you are not in a hurry, so why cut corners here? Your truck was built many years ago and if you address all you can now that you have access, you won't be sorry later.
All you have to do is disconnect the harnes from the sensors on the side of the engine and, I think, three connectors above the starter and the two O2 sensors. No need to disconnect it from the transmission because one of the connectors above the starter continues on to the transmission. My O2 sensor lead that travels accross the top of the trans was damaged as well as some other areas as I stated before. Once the above mentioned connectors are disconnected you can inspect the harness easily. I bought a brand new OEM harness from Cruiserpart.com for $400. Not saying you will need a new harness but I am saying that I have peace of mind knowing that all of these life limited parts are now new and I know that all wires and hoses are routed in a manner that will best prevent rubbing and chafe through problems later.
This is an opportunity for you to get very intimately aquainted with the under hood area of your 80 and since you don't depend on it for daily transportaion there is no logical reason to not be thorough with this very important aspect of your vehicle especially when we consider the amount of money an time we dedicate to modifications.

 

[AJP]

I did not remove the block sensors but did remove the wiring plugs....you should tie back the intake manifold as others have advised ...run a cord down to the DS wheel. This will keep the manifold away from the sensors....however I won't lie and you may find that occasionally the manifold will come close to the sensors and you need to be alert...OR remove the sensors.... just make sure you use the proper tool to get the off.

 

[AJP]

...what Baldilocks is telling you is the FSM recommended approach AND will let you remove AND replace the head with the intake manifold and head assembled....which IS a better way to do this (If you can get the main wiring harness removed!)

 

[Azca]

Remove the sensors on that side of the engine, they are all spendy ($100 plus each) The extra time to remove them could keep a little padding left in your wallet...

 

[Rwhat]

Just a heads up. I did mine this past year. What helped my back a lot was getting some 2x6 wood blocks and screw them together. Then jack up the front end remove tires and place the wood under the control arms under the axle. You can probably go lower then I did.
Make sure to cap off the fuel lines. My garage got hot and I think the return line puked gas one day.

 

[2fpower]

Injector RX

12201 Dover St

Houston, TX 77031

USA

 

[Rwhat]

I also used injector Rx. Was the most reasonable place and seemed to have good reviews. I was happy with their work and turn around time.

 

[Jorgito]

Update:

I had a lot of problems with the nut and two bolts in the lower manifold to the head near the firewall. I could not use the racheting wrench end ended up somehow removing it with the 3/4'' rachet. I don't know how I am going to put it back together.

I pulled the manifold to the side as suggested by many on this forum and also as Doug suggests it in the video. I went to buy Motororcycle strap and also one x6/1 16mm.

I put the zip ties around the chain and took the chain tensioner out, then I had to take the distributor gear out with the nut which gave me some issues. I ended the day by removing the camshafts which at the end was not so difficult.

nut out

• Jorgito
• Nov 11, 2015

intake out

• Jorgito
• Nov 11, 2015

exhaust camshaft

• Jorgito
• Nov 11, 2015

camshafts

• Jorgito
• Nov 11, 2015

 

[baldilocks]

The important question is: How will you properly torque the rear manifold to head bolt if you do ever get it started? This is why I have been urging you to follow the book and forget short cuts that cost you in the end. Do it right once.
Have you purchased new head bolts? Or ARP studs perhaps? There has been a lot of debate about whether or not to re-use the head bolts. Mine checked out good per the manual but I opted for the ARP studs for their ability to apply a greater clamping force that is more evenly distributed. And the best part is they cost less than OEM bolts.

 

[Jorgito]

The important question is: How will you properly torque the act manifold to head bolt if you do ever get it started? This is why I have been urging you to follow the book and forget short cuts that cost you in the end. Do it right once.
Have you purchased new head bolts? Or ARP studs perhaps? There has been a lot of debate about whether or not to re-use the head bolts. Mine checked out good per the manual but I opted for the ARP studs for their ability to apply a greater clamping force that is more evenly distributed. And the best part is they cost less than OEM bolts.

Taking the whole manifold out is probably the right way to proceed, me as a noob am facing conflicting advices and suggestions here on ih8mud. Half of people here or maybe more are following the way as it is described on the famous DVD where the manifold is just put on side without raking out the engine harnes.

I am simply following the majority here, the true is that if we take the manifold out as described in the DVD, there is no proper way how to torque ghe manifold to the head.

I am still not decided about the head studs

Jorge

 

[baldilocks]

Taking the whole manifold out is probably the right way to proceed, me as a noob am facing conflicting advices and suggestions here on ih8mud. Half of people here or maybe more are following the way as it is described on the famous DVD where the manifold is just put on side without raking out the engine harnes.

I am simply following the majority here, the true is that if we take the manifold out as described in the DVD, there is no proper way how to torque ghe manifold to the head.

I am still not decided about the head studs

Jorge

Opinions are only opinions. You will never go wrong by following the FSM. I find toyota manuals to be rather straight forward and easy to follow.

 

[AJP]

Opinions are only opinions. You will never go wrong by following the FSM. I find toyota manuals to be rather straight forward and easy to follow.

Absolutely agree! I would have liked to follow the FSM with the harness but I couldnt see how to get the harness off without dropping the transmission and said screw it. I was also not keen on removing the harness from the ECU end although I have replaced the ECU in the past (unnecessarily). The route that the harness used was designed to be expedient during assembly when the powerplant/transmission was sitting in a cradle waiting to be hoisted into the bay. Not while the engine was in the vehicle. FWIW I found that I could reach all the intake manifold bolts/nuts with hand tools and you can get very close to the correct torque (when torquing aluminum to aluminum where the values are pretty low) by "feel" on the few bolts that you cant get a torque wrench on. Of course you must remove the starter to get to some of the upper intake bolts from under the vehicle and you should allow for the multiple extensions used when applying your torque wrench.

I cant comment on ARP bolts ... if they are cheaper than OEM and fit properly without resorting to shortening bolts designed for other vehicles and (apparently) if you plan to re-use them ... then ARP is probably the way to go.

ABSOLUTELY FOR SURE you MUST measure the headbolts you remove BEFORE assuming that you can re-use them: one of mine was out of spec and another was very close to the allowable limit ... I replaced them both. The rest measured ok and well within the FSM specs - they were reused. They went back ok ... so far .. so good. Personally I DO NOT LIKE torque to yield head bolts and think they are a solution to a problem I never I used to have.... although maybe they are considered a requirement with aluminum heads. I understand that the dealerships will automatically replace all the head bolts when they remove them .... for me however that would be an additional $498.33 Cdn with tax. Thanks but no thanks ... if they were worth that much -- I shouldnt have to be replacing them! Incidentally Jorge .. if you havent taken the hood off ... you will need a small "dental" style mirror to assist you in putting the white paint dots on the rear headbolts when you start the final 2 tightening sequences.


(btw baldilocks - I believe you said that you ended up replacing the engine wiring harness - IF I was going to replace the engine wiring harness - I would certainly have reconsidered my approach to the HG R&R ....and in my case I did not buy or acquire the famous DVD .. I actually followed most steps in the FSM except the as I identified on my previous thread)

 

[baldilocks]

Absolutely agree! I would have liked to follow the FSM with the harness but I couldnt see how to get the harness off without dropping the transmission and said screw it. I was also not keen on removing the harness from the ECU end although I have replaced the ECU in the past (unnecessarily). The route that the harness used was designed to be expedient during assembly when the powerplant/transmission was sitting in a cradle waiting to be hoisted into the bay. Not while the engine was in the vehicle. FWIW I found that I could reach all the intake manifold bolts/nuts with hand tools and you can get very close to the correct torque (when torquing aluminum to aluminum where the values are pretty low) by "feel" on the few bolts that you cant get a torque wrench on. Of course you must remove the starter to get to some of the upper intake bolts from under the vehicle and you should allow for the multiple extensions used when applying your torque wrench.

I cant comment on ARP bolts ... if they are cheaper than OEM and fit properly without resorting to shortening bolts designed for other vehicles and (apparently) if you plan to re-use them ... then ARP is probably the way to go.

ABSOLUTELY FOR SURE you MUST measure the headbolts you remove BEFORE assuming that you can re-use them: one of mine was out of spec and another was very close to the allowable limit ... I replaced them both. The rest measured ok and well within the FSM specs - they were reused. They went back ok ... so far .. so good. Personally I DO NOT LIKE torque to yield head bolts and think they are a solution to a problem I never I used to have.... although maybe they are considered a requirement with aluminum heads. I understand that the dealerships will automatically replace all the head bolts when they remove them .... for me however that would be an additional $498.33 Cdn with tax. Thanks but no thanks ... if they were worth that much -- I shouldnt have to be replacing them! Incidentally Jorge .. if you havent taken the hood off ... you will need a small "dental" style mirror to assist you in putting the white paint dots on the rear headbolts when you start the final 2 tightening sequences.


(btw baldilocks - I believe you said that you ended up replacing the engine wiring harness - IF I was going to replace the engine wiring harness - I would certainly have reconsidered my approach to the HG R&R ....and in my case I did not buy or acquire the famous DVD .. I actually followed most steps in the FSM except the as I identified on my previous thread)

I just remembered that Jorge's 80 is a 97 model. Mine is a 1994. Perhaps the harness is different and perhaps that's why it costs over $200 more.
I did not have to disconnect from the transmission. Except for the O2 sensors, all engine harness connectors terminated in the engine bay above the starter and then from those connectors extended on down line to other components like the trans. So, Toyota may have made some changes with respect to the harness.
Removing the harness from the ECU end is not so difficult either. At least not on my 1994.

 

[Jorgito]

Jorge .. if you havent taken the hood off ... you will need a small "dental" style mirror to assist you in putting the white paint dots on the rear headbolts when you start the final 2 tightening sequences

I will use the "angle degree torque gauge" as suggested by Eric the Car guy. I think that it is pretty neat tool to have.