decarbonizing the engine head

[john_d]

Is it necessary to remove the head from the engine and then decarbonize the head of a 1Pz every 100,000 kms?

Recently, because of a possible intake valve leakage, the head of my 1Pz engine was removed the valves were lapped. Is this the correct remedy for a leaking valve and could there be any long term damage from valve lapping?

Also, I suspect that the garage may not have used a Toyota OEM head gasket when reassembling the head with the engine. How serious a problem could this be? What remedial steps should I take?

Lastly, could anyone point me to a maintenance manual for a 1Pz or a owner's handbook for a 1Pz70. I couldn't find it from the links for manuals which are on this website.

Thanks
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1PZ70 (1990)

 

[brownbear]

The manual is the same one for the 1hz engine. It covers the pz too. So download that manual. It will have all the info for your engine.


Valve lapping is not very intrusive IMOP. I doubt it would have long term effects.

But I doubt you need to pull the head every 100k either. That sounds excessive. Where did that info come from? Just curious.

 

[BiG BoB]

Steps to decarbonise the combustion chamber, and port/polish the inlet and exhaust:

Step 1:
Open the bonnet, remove the air filter cover and filter

Step 2:
Start your vehicle, setting the hand throttle to around highway revs (or use a brick)

Step 4:
Slowly pour sand blasting sand into the air inlet, the sand will travel through the inlet cleaning up the inlet tract, swirl in the combustion chamber dislodging carbon deposits, and then clean the exhaust tract on the way out.

Step 4:
Replace air filter and cover, you're all finished

The above post was of course made in jest...

As for the head gasket, I'd check with the shop that's done the work, provided its a brandname gasket it shouldnt present any major problems...

I would deffinatly check that they havent gotten a 1HZ gasket and trimmed it to fit however!

Sean