350 TBI coolant leak @ intake manifold

[Kirth Gersen]

'94 350 TBI ... the front corner, passenger side of intake manifold is weeping coolant. Seems the thick silicone/RTV bead may be failing. Engine has about 250K miles and never been opened.

1) It may be weeks before I can get to it ... is there any immediate danger of coolant getting into the oil? The oil on dipstick looks OK & normal.

2) What is a typical time to replace the intake gaskets?

3) What is the preferred gasket set -- OEM GM, Felpro ??
Rock Auto lists ACDELCO # 12525810 and FEL-PRO MS93317 .

4) Are there any 'gotchas" or things to watch for, there aren't in the GM service manual?
Example, somewhere I've read the center 2 bolts on each side will weep oil, unless sealant is applied to those bolts.

5) Any other work that should be done while the manifold is off?
The notorious heater hose connection at rear has already broken off once, and it looks sketchy again. It was big PITA repairing it 1st time, the female threads were partially destroyed & I'm thinking to have machine shop insert a helicoil while manifold is off.

 

[chipskittles]

1) fix as soon as you can, the gaskets can be leaking internally where you can't see as well as externally.
2) depends on your mechanical level. Nothing particularly hard about pulling the intake but you will be disconnecting fuel lines and coolant lines and coolant will probably get in the valley unless you are pretty diligent about draining the block first. I have performed engine swaps and rebuilt lots of things and have been taking apart things since I was four and I would still set aside an an afternoon in good weather to pull an intake and replace gaskets.
3)Felpro is preferred.
4) and 5) intake bolts are all different lengths and styles. Some are studded to accommodate accessories for example. Keep them all straight and take pictures of them all in their original locations and you will save hours of time there. Replace the throttle body gasket and of course that coolant quick disconnect while you are at it. I think you can get oversise coolant hose fittings if it comes to that. Should not be hard to repair the threads or tap new ones with the intake off. Clean out the EGR passage too. It is no easier to clean than when you have the intake off the motor. Be prepared to clean out the valley because it will likely be disgusting if if it's never been opened up and depending how the intake seals have been leaking. Pull the knock sensor and the block drain to fully drain the block.