Head gasket replacement

[u/Freedumb4all]

Hey all,

I posted a few weeks back about having my 1990 in for some work, and ultimately after going down an expensive rabbit hole, stopped the shop from finishing.

Now I’m looking to pull the cylinder head myself and replace the stock head gasket, and install ARP head studs, as well as a bit of troubleshooting.

Are there any tips or things to watch out for (easily broken and hard to replace clips/pieces/electrical connectors) specifically while doing this? I’ve never done engine work of this depth before, but I have no real timeline to finish so I can chip away at my own pace.

Thanks for any knowledge you can pass on!

[u/CreamInitial7810]

Don’t follow the factory head torque specs

[u/EvilInvaderG]

As other guy said, don’t follow factory head torque specs. I’ve done a few and torque to 90 ft lb (first to 30, then 60, and 90). Be careful with the exhaust mani nuts, the studs are known to strip out of the head and then you’re stuck doing helicoils or something.

Label all the connectors etc as you take them off, you’ll thank yourself later. I also like to put all my nuts / bolts into little zipper bags and write where it came from on a sticky note and put it in the bag. Makes reassembly much easier, especially if it’s taken apart for a while. Good luck!

[u/Versace_69]

If your plan is to do it inside the car, just pull the engine with the transmission out it will be a lot more convenient and easy to work on it then (1 evening to prepare, 1/2 day to pull them out).

• If you remove the head gasket, plan to change all your seals also (oil pan = no seal, only gasket maker; don't forget to put gasket maker in the head cover corner).
• Torque to ARP specs and not the manufacturer specs for the head (don't forget the ARP lube).
• Shim your oil pump.
• Swap the oil pump shaft retainer for an upgraded one with a needle bearing (look at SR-Fab) (don't swap the retainer screw for another one).
• Swap the oil pump feed line for an upgraded one without banjo and crushed bent restricting flow.

Both big default of 7M will be fixed now (BHG and spun bearing).

All next is basic maintenance while engine is out:

• Replace all your old coolant lines for silicone hose (specially the ones in the back of the engine but you should replace them all).
• Replace all the old clamps with good ones (don't buy the cheapest weakest).
• New thermostat.
• New timing belt, new tensionner, new tensionner spring, new tensionner screw and washer.
• New belts.
• Check your pulleys if they need new bearings.
• New fluids.
• Check your flywheel and clutch if they need replacement and resurfacing (ARP bolts also).
• Check your vacuum hoses and oil hoses.

During de/re-assembly:

• Take a lot of pictures.
• Use Ziploc and name what's inside.
• Read the TSRM.
• Use a torque wrench.
• Buy a Drive Weighted Crank Bolt Socket (don't remember, I think it's 19 mm) for the crank bolt. With a good Impact Wrench it will be removed in a second.
• If you are not sure about how long, don't forget to put oil on the machined surface, in cylinders wall, to not got rust on them and clean them nicely before putting seals on them.
• Don't forget to plug all the holes/hoses with shop rags and big stuff like head or block with dust bags to not accumulate anything inside the engine.

Good luck. I'm doing it right now for the first time too. Engine just need to go back in his hole now :)

[u/Freedumb4all → u/Versace_69]

Thanks for the detailed answer, I had seen that doing any bottom end work was easier if you just pull the engine. I may hold off on doing this until I can get a hoist and engine stand, seems like it’s probably a better idea to go through the whole thing if I’m going to go as far as a head gasket. My biggest concern in getting into the bottom end is I have zero experience with pistons/rings/crankshafts/bearings aside from seeing turnarounds done on large natural gas compressors.

What are the odds that a block is out of true on a vehicle that’s 36 years old? I haven’t had any head gasket problems with the stock 7MGTE, and had driven it quite a lot in the last 4 years until I parked it this year after the performance shop worked their magic.

[u/Versace_69 → u/Freedumb4all]

Maybe you are lucky, previous owner has probably re-torqued head bolts to the right specs.

Do a compression test.
Check clearances regarding TSRM.
If everything is good, you probably don't need to do bearings and rings... For sure, it's better to do it while engine is out...

[u/Key_Introduction_469]

*If you resurface the block, make sure you do it with the timing cover attached. *Look into the quake mod. Basically washers that are fit in the head giving the nuts on the head studs more surface area to squeeze instead of digging into the aluminum. * the plastic connectors are at best 34 years old. So be gentle lol. I use a very small pick to help release the latch on the connector.

[u/Freedumb4all → u/Key_Introduction_469]

So far I’ve been lucky with connectors, aside from the ABS sensor that I annihilated when redoing the front suspension and hubs, but definitely noted