pbnolan86

I have a 99 Mustang procharged with 10 pounds of boost. Just recently I developed a miss and started investigating. I found coolant in several areas on the spark plugs and coils. I ran a compression check and everything is fine. I changed the lower intake gaskets because the miss felt the same as previous issue that the gaskets fixed. This time it didn't fix it. Coolant showed up in the same places and I cannot find the leak anywhere as there is no coolant any other places except for wells of the spark plugs. If u start the car it will run fine until the car warms up and thermostat opens and then here comes the miss. I understand the crossovers are weak in this car but how can coolant be on top of several plugs on both sides of car without any other coolant sitting anywhere. Please help this is my daily driver and now have been without wheels for over a week.

mvr

definately sounds like a cracked intake. i assume you have the full plastic one? get the intake manifold with the aluminum crossover. or an aftermarket one.

pbnolan86

When u say aluminum crossover r u talking about the very front of the intake where it goes from thermostat housing all the way across to the other head right behind alternator because on my intake that part is all metal but I think there is actually 4 small bolts that hold that section on to the actual plastic intake. Just trying to understand the difference between all these intakes. Thank you

stevednmc

yes....thats what he's talking about, but even those intakes have cracking issues over time.

pbnolan86

Where does the cracking normally take place and why is there no coolant anywhere else other than the spark plug wells on the heads

stevednmc

I know ive seen pictures on here somewhere.....will search.

pbnolan86

Thanks alot

stevednmc

Here are some good threads:

https://mustangforums.com/forum/4-6l...heating-2.html

https://mustangforums.com/forum/4-6l...uld-i-get.html

Search is yo fwend...just typ in the search bar cracked 4.6L intake manifold...a whole wealth of info is there.