Valve Cover Gasket Replacement

[LittleCaesar]

I think that the head of the 5vz was indeed used in another Toyota non US model, but I cannot remember offhand. Prado, Hilux?

It is worth the time to remove, clean and reinstall them with new FIPG when changing gaskets.

 

[sigley0527]

Not to steer this thread off topic, but I'm sure you all are familiar with the valve cover bolts coming loose. I first noticed this when I thought my valve cover gaskets needed replacement due to the amount of oil seepage. I realized that wasn't the case when I saw that the bolts were super loose for no reason. I find myseld having to retighten every few months.

Does anyone have any suggestions to get these bolts to stay tight? Maybe lockthread?

 

[takumi]

could maybe try mild strength locktite. I imagine just a little locktite would work.

Not to steer this thread off topic, but I'm sure you all are familiar with the valve cover bolts coming loose. I first noticed this when I thought my valve cover gaskets needed replacement due to the amount of oil seepage. I realized that wasn't the case when I saw that the bolts were super loose for no reason. I find myseld having to retighten every few months.

Does anyone have any suggestions to get these bolts to stay tight? Maybe lockthread?

 

[robb1887]

Maybe something needed for the casting or machining process?

I always hope the engineer that specified something like this will chime in discuss with us.

I'm not the engineer that designed this head, so I am speculating.

I would suspect they are there so that the journal bearing lands for the camshafts can be line reamed to ensure they are all 100% aligned. I would bet the original casting has the journal bearing lands a bit undersized in the head casting, & the bearing caps are a bit undersized and then machined together to ensure a 100% perfect fit to the camshaft OD.

You wouldn't be able to ream them if that "half moon" was part of the original casting

 

[Stuck]

Anyone took a side by side comparison between a new gasket and the old ? Aside from the spark plug tubes, would it be worth just cleaning and using rtv to repair the old seals ?