without removing valve cover, during main timing cover removal?

I've been plagued by oil leaks since fouling the head gasket extensions that are between main timing cover and upper timing covers. Oil pan and timing cover removal is in progress, & I plan on adding paper gaskets between upper and main timing covers.

If possible, I would like to remove and reseal upper timing covers - these are the two covers in which VVT actuators mount, that seal to valve cover, engine block, and main timing cover. Camshaft position sensor is mounted on LH upper TC.

Also, is there a URL for IOS parts, or is it necessary to call? I need engine mounts, and a gasket or two.

Thanks in advance.

And the answer is yes, but not very well: RH upper timing cover sits above the engine block, at the plane of the cylinder head/block interface, (RH cylinder head is set back an inch or so rearward, it's timing chain is rear most on crankshaft) also, RH upper timing cover mounts beneath the valve cover, so to reinstall without removing VC means a tight press straight into the slot formed by the valve cover and block, nearly guaranteed to displace RTV sealer, and possibly to screw up the head gasket extension at the above mentioned interface.

So as usual, there is no shortcut here, the right way is to first install upper TC, then valve cover.

Actually, it's probably best to install main timing cover first, then oil pan, then upper TC's, then valve covers.

It's been a while since I was last under timing cover, now I recall LH timing chain tensioner mounts in upper front cover. I have main lower cover removed. I would like to remove and reseal LH upper cover, so slack side guide will not have tensioner during upper cover R&R. Will timing slip when tensioner and both front covers are removed?

Thanks!

I have R&R the upper RH side cover (with VC off). I have not done the LH upper cover. since you have lower cover off, I would suggest getting HD zip ties and cinch those bishez down hard before removing the tensioner. while you have the tensioner out, would be a good time to clear the oil passage good, and also replace the o-ring. i used permatex grey between the cover and the head and also very very lightly (finger smear) where it pinches the head gasket.

I only wish I still had head gasket there, mine got screwed up and broken off earlier. Oil leaking is why I'm all in here. I have not had good success with RTV alone, single layer of paper gasket also leaked. When I removed covers, gasket paper was saturated w oil, my guess is that it is not thick enough.

Head gasket measures 1.2 mm thick, single thickness of gasket paper is 0.6 mm, single thickness cork gasket material is 1.5 mm. I'm tempted to try the cork. It's either that, or double thickness of gasket paper.

My plan is to install lower cover first, then upper covers, to be sure gasket and sealer between lower and upper are properly in place, then valve covers, then oil pan.

The only problem I can foresee is to not lose timing when lower and LH upper covers are off, leaving slack side guide free. I guess I can try to install lower cover with zip ties on LH chain, then reach through and remove zip ties before replacing oil pan.

use a sharpie to mark chain and sprocket index before removing tensioner and then you will know if it slips.

Very good idea, thank you.

I did finally understand the source of my rather bad oil leak: The paper gasket between LH upper and lower front covers sheared; the paper I used is 0.60 mm thick, and what I found was lower cover had paper 0.30 mm stuck to it with RTV, as did the upper. Some how the gap between upper and lower expanded, and the RTV is strong enough to in effect delaminate the gasket paper, splitting it through, planar. Both surfaces of the paper were unfinished, and saturated with oil, also the fasteners seemed very loose. I've caused myself no end of work by f'ing up my head gasket extensions. Odd how the paper split so evenly, obviously too thin for the application. The RTV bonded it to cover mating surfaces very well.

So I will not remove LH upper cover or LH valve cover, will use the 1.5 mm thick rubberized cork gasket material, and RTV, install lower cover against LH upper cover in place, then RH upper cover, then RH valve cover and oil pan.

interesting, thanks for sharing that. Don't know the history of the engine in your '92, but I'll ask the obvious....the slack side guides have been replaced with the metal backers, yes?
even if so, good time while lower cover is off to make sure the oil pump chain has not been digging into the pump shaft housing.

Guides are upgraded, I've driven it about 5000 miles since. That's when head gasket extensions got ruined. I've seen no evidence of oil pump chain interference, was not aware of any related issues.