jawknee5

Hey guys, recently noticed the smell of coolant after warm up- So i did some detective work and behold i found coolant seeping from my intake manifold. Its around the rear bolts and it looks like its coming from the gasket, though i cant be 100% sure its not cracked, but it doesn't show any obvious cracks.

Do you think it could just be the gasket? Could this be another bigger problem that just hasnt reared it ugly stupid face?

How involved is it to change the gasket myself, and how much would it be to have a mechanic do it?

Ive looked around for other threads but most involve a cracked manifold and theyre upgradin to a pi intake- and im not looking for anything like that.

Also- if there are any wrench friendly people on this forum in the OC california area interested in maybe doing it for a little cash- Let me know.


Anyway, any input would be helpful. Thanks

tadpole1969

i seen a thread that spoke of a coolant fitting on the back passenger side of the 4.6 ,close to the far back cop that was prone to leak ,migth be your issue

uberstang1

Alot of times a hairline crack is not easy to spot with the manifold on the car, regardless your going to have to remove it to replace the gasket, so remove and inspect and go from there.

JohnLanier

FYI (in case you didn't know): The 4.6L 2V intake manifolds on the GT are composite plastic w/ an aluminum crossover for the coils (Ford did a recall in the early 2000's on this part for the coolant issue)..I had a similiar issue a few months back and the leak was where tadpole1969 mentioned (i.e. right where the hose connects to the manifold)..in my case, the crack was small enough that I decided to try a little Gorilla Glue on it, and I haven't seen a leak in that spot since (probably not recommended, but it's working in my case)..and if you're considering a manifold swap (I know I am), note that some of the 1992-97 Crown Vic's/Marquis's/T'Birds have ALL ALUMINUM intake manifolds (I know this after visiting a local junkyard and seeing it for myself)..the procedure is well documented on the WWW and in my Chilton Manual, but if anyone has done this swap and has any words of warning/wisdom/etc. to share, I'd appreciate it..

sn95fan

Just had the same problem in my 4.6 it was the rear gasket, I replaced all the gaskets on the manifold and now no leaks so i'm going to say it is the gasket.

But before replacing gaskets black light your manifold it will show if you have a crack or not plus it will show where the biggest part of the leak is coming from. just had to do it all this week, but be careful on replacing them my car isn't running right now and cant figure it out so be very careful just saying.

jawknee5

So once you replaced the gaskets it stopped running?

kast1376

My manifold cracked at where the crossover met the plastic. Did the swap and now I have a knock at WOT, but no other time. Haven't found any vacuum leaks yet, so I am worried the brand new manifold is cracked on a runner.

JohnLanier

Sorry for getting off-topic..but I went to the junkyard on Tuesday and found out that the intake plenum on the 4.6L CrownVic.s/Marquis's/T.Birds I had looked at a couple weeks ago are different than on my Mustang (i.e. the plenum comes up from the top/back of the upper intake manifold on those , while mine sits closer to the center) so the aluminum MF swap I had in mind won't work without some kind of redesign..so the composite plastic one looks to be the easiest swap/path of least resistance..

sn95fan

It didn't quit running it just isn't running right. I figured out my problem though, but I still don't know why the problem happened after I did all this work and not before. But come Friday it will be running right again.

IH560

When my car had a coolant leak from the intake manifold it was on the back driver's side of the manifold and it cracked at that rear most mounting bolt, which holds down the manifold and blocks off the coolant passage. Mine would only leak when the engine was cold, once it warmed up the leak would stop. It was also allowing coolant down around that spark plug and shorting out the coil.

I have seen cracks at all four corners of these manifolds, where the coolant passages are. It could be any one of them causing your issue, or just a gasket. My crack was not apparent until I had completely removed the manifold and took a very close look at it.

https://www.dropbox.com/sc/yxtzf6iax...8xEqM1AzDLw6na