Hey all you head gasket experts, just pulled this off yesterday and from my limited knowledge it looks to me like leaking might be happening in between cylinder 1 and 2 which also seems to correspond with the silver part where the material has gone missing in head gasket. It looks like coolant could get in between cylinder 1 and 2. Also on the head it looks quite a bit different in between 1 and 2. Otherwise this head looks pretty good fairly in spec and hoping I can do a few clean ups and put it back in motion. Can anybody provide more insight into this for a rookie? Also shown is the clogged egr which probably caused this problem on 2012 now at 215,000
That picture of 1&2 cylinder bridge on the head just about says it all. Plus there are signs of moisture from the coolant all over the combustion chambers. BTW, I would carefully inspect that cylinder head with a good straight edge, for flatness. Might be good to check the block deck, too. When you reinstall the head ( if everything checks out good), make sure you use new head bolts. Torque to yield bolt must be replace with new. One more thing: Did the any of the head bolts feel as if they yielded a bit too easy when you removed them? You want to make sure there is no potential for a stripped thread in the engine block. Carefully check the block around the head bolt holes for any crowning. Hopefully you’ll find them to be okay. If not, you may have to helicoil the block.
Thanks for the input, I can tell you have experience with this. Is it imperative to get new head bolts? They all felt solid when I took them out and looked good on inspection?
Horrible. Yes never reuse head bolts. They stretch under the initial torque. I know you don't want to go back in and fix that. Its a good idea to get a tap the thread size and chase and clean the block threaded holes out too,
Don't forget to check depth of the pistons below the block deck when at TDC. If any rods bent from the gasket leak, it should show up as a difference in deck clearance. Would hate to go through all this effort and then grenade it a week later due to a bent rod....
Given the many variables like TMR just brought up might be cheaper to buy a used motor. Then stay on top of the egr cleaning. I would never buy a G3 this EGR situation is really bad and Toyota should eat this and start a TSB on it.
Toyota does provide directions on measuring the head bolts for re-use. If the bolts have not stretched beyond the specified limits they can be reused. But yes, buying new bolts would be easier. Between cyl 1 and 2 is usually where the gaskets fail. I would check the block with a straight edge to confirm that it is flat. Also check the piston height to the deck and make sure all cylinders are even; if you have a bent connecting rod, you need to find out now. Take the head to a good machine shop and have them clean it up, check for valve sealing and install new valve stem seals. Resurfacing may not be a bad idea, but any material removed can potentially cause timing issues. MLS gaskets need a smooth surface (50ra or less) to properly seal, but taking off material can cause timing issues....so it is a double-edged sword. Make sure you clean the EGR cooler and EGR valve, and also install a new w/p and thermostat.
The combustion chamber cooling EGR gasses enter the intake manifold at driver's side, after having been "cooled" and passing through this:
There's actually a warranty extension program, but owners by and large are saying thanks but no thanks. They commence the communication by saying "while the majority of owners will not experience....". Which translated means "we are lying through our teeth". Then there's the warning lights and trouble codes: even with the EGR cooler looking like the above pic, the car says "nope, nothing to see here, everything within specs".
