Problem 1...

I recently replace my intake manifold gaskets, on my 89 Formula 5.7L TPI motor, because coolant was building-up onto the top left (passenger side) of the intake manifold. However, even with the new gaskets, the coolant is still appearing and slowly running down the front & back of the manifold (and down the block).
I am considering buying a new Edelbrock manifold but, before I spend about $375, I thought I would see if anyone had any ideas as to why this could be occuring. As a side-note, I also noticed that the engine seems to idle somewhat roughly and get pretty hot when sitting at a stoplight. I'm not sure if this is related, but I thought I would note it.

Problem 2...
Sometimes when I drive my car, it has great throttle response/torque throughout the powerband. Other times it seems to be sluggish - especially at mid-range. Can anyone suggest something(s) I can check that would cause this to occur?

I am new to the forum and would greatly appreciate any advice. Thank you.

 

One of my intake bolts held a big looped ground wire. I added a ground to that connection cause it looked nice and easy. Being as I knew I was tightening the bolt into aluminum I didn't torque it down.

next thing I know it's leaking coolant. Found out that intak bolt went through the water jacket and neeeded to be tight.

Is it possible one of your bolts is loose or stripped out. I am not sure if the intake bolts go through a water jacket on your motor

 

did you clean and oil the threads on the intake bolts? did you use a torque wrench and properly tighten the bolts? I've fixed many of these leaking antifreeze ...always the same thing......bolts are not properly torqued!

 

Make sure you use a thread sealant on the intake bolts or else the antifreeze will wick up the threads and leak out. Also make sure you prep all surfaces with adhesion promoter and the gaskets when re-installing. Just ask any quality engine rebuilder and they will set you straight. There is a proper technique to installing an intake on an L98. Its the kind of thing a guy hates to do twice....don't ask how I know

 

i've done alot of them.......just oil the bolt threads and torque um with yer torque wrench....nomo leaks ..its that simple

 

Thank you to everyone who replied to my post!

When I put the intake manifold on, I did use the proper torque sequence and correct amount of torque (according to my Haynes guide). I also cleaned the bolts (and everything else) the best I could and used brand-new Fel-Pro gasksets. However, I wasn't aware that the bolts required either thread sealant or to be oiled.
Thanks again.

 

if you used the heavey blue fel pro gaskets you may have a problem with leaks........i use the standard GM gaskets or the replacement equivalent from the local parts place.I tried the Fel Pro heavey blue coated gaskets once and couldn't get them to seal either.I've also noticed if you don't lubricate the bolt threads and cap of the fasteners the proper torque is never reached......you get sticktion of the bolt threads=false torque readings where the force applied is not true because the threads are dry.The torque you are applying is not enough to properly tighten the bolt and overcome the force to turn the bolt in the dry threads.Lubricating the thread area and cap assures proper torque is applied.This should be done on ALL threaded fasteners in an engine if you want proper torque.