90 GXE head project

I am going to tackle a big project. I have a badly-leaking rear exhaust manifold, broken studs, etc. I have decided to bite the bullet, remove the heads and replace all of the studs. I just can't imagine that I could do it with the heads still on. The car and engine have about 200K miles on them. So, I have a head gasket set, including valve stem seals. I have no reason to suspect that the heads are warped at all. Should I have them checked? Can they be planed still assembled? Or, do I have to remove everything just to get the new seals on anyway? Should I even bother with the seals? I am also replacing the fuel injectors, at least one is bad. At the same time, I am going to replace the timing belt, water pump, and front main seal. I have the factory service manual, the Haynes manual, and have and will read any applicable page on Wiik's cardomain site (very informative and helpful. Thanks Wiik!) I am a retired auto tech, no special experience on Maximas. Now... any special advice or comments on my plans? Am I crazy? I am dropping over $500 on parts ($200 just for the head gasket set and $200 for a new exhaust manifold that I may or may not actually use). Any thoughtful comments are appreciated!

-mike w

- thanks for site thanks. Lots trouble just to hlp yall ppl.

- check out the overall financial entity: price compared to low mileage engine compared to all possible problems, seals etc spares costs. (Some say that low mileage 'perfect' GXE's go under under 1k )

- if u dont count your time and chassis is ok, its really cost effective if u keep the car 5yrs or more

- lots ppl have replaced the studs after 'dropping' the engine as low as it may come. Seems quite tight job, but if valves are ok, I'd try that route. (No experience yet: I am waiting to know if my VGE bolts start to go - or if theyre the better 'later' quality)

Heads:

- stem seals can be replaced while head is on place by pressurizing cylinder while taking springs out. (I guess ? putting piston up would be enough)

- my quess is that maxima has stretch type head bolts, cant be used twice? check manual.

- if heads have no leaks, noo need for planing (wont hurt). You know only when u see them opened

- those shops I have had my heads planed, have all required valve dismantling. Call your shop, ask ppl for recommendations: there are good & terrible shops

- if take heads out, valves shoud be taken out, checked and machined if necessary

- be prepared in buing all new exhaust valves

After a costly job, its not nice to find crank seal (tranny side) leaking... my experience on one vehicle. How about taking engine out, but leaving heads as they are (only injectors, stem/cam etc seals)?

Who is the one who can say if one is crazy? From my point of view, all trying to measure, are the craziest ones... Lets not worry, but be happy as long as we are physically fit to work: the "cant be done, youre crazy" -crowd wont/cant ever work or stop singing. So go ahead, u can do it!