Hi all, new member here. Problems with my engine forced me onlien to search for help and and thrilled this site exists. Look forward to some new reading material. My immediate problem is this...

I was told I need to replace the engine in my 99 Mustang GT because of a crack in the intake manifold and the engine block. This news really shocked me, as I wasn't expecting this to be the problem at all, but nonetheless, I was just looking for input on where to go from here...

My mechanic told me I could go with a rebuilt 4.6 or a 5.0 mustang engine, but I've heard that putting a 5.0 in a 4.6 can actually be a down grade. I don't know much about cars, just that I love my stang. I would like to do some upgrading in the engine department if I'm going to have to replace the entire thing, but am not sure what is compatible with the gears (it's manual), computer, etc.

Any help is appreciated

 

if you doing the work yourself you could get a new block and then transfer the rest of the engine to the new block. depending how much money you got you can buy a long block, create motor, rebuild what you have, or what i'm leaning too is buy a 4.6 cobra motor with trans and computer.

putting in a 5.0 is a down grade in power, upgrade in cubic inches, go figure! 98 and up have the power improved heads.

 

99 and up have the PI heads and intake btw. If you want to put a 5.0L in your new edge you will need a host of other things to make it happen. New k-member, bell housing maybe and a new driveshaft and some other stuff. I would shop around on Livernois or other engine builders and get just a nice 4.6L short block built, maybe bored with some high comp pistons then get your mechanic to put your heads from your engine on it. Your know it could be a good time to change cams and port the heads too.

 

Your mechanic is NUTS to recommend replacing the 4.6 with a 5.0! Nothing wrong with 5.0's by the way, but unless you already have a really sweet one on hand looking for a car, then swapping is just plain stupid.

A blown Cobra 4.6 would be totally sweet! but for the sake of keeping things a bit simpler, maybe look around for a 4V Mach 1 motor. That'd be sweet & it would fit no problem

 

are you sure the block is cracked? Did you run it hot as hell?

anyway you can probably get a replacement GT motor for 500-1000 bucks.

 

Thank you all very much for your replies....Heres an update...

I was wrong about what he said with replacing the 4.6 with a 5.0....That was what a friend who doesn't know anything said....My mechanic was talking about replacing it with a 4V (cobra) engine. However, what he wanted to do first was ONLY replace the intake manifold.

I went online and ordered a PI intake manifold which I confirmed would fit my 99 stock GT heads as long as a new hose was used. My mechanic wants to see if that clears the problem. He said the crack is in the manifold but he's concerned the block may also have a problem.

It would be a much cheaper job to only have the manifold replaced, but I'm going to be honest, I'm almost disappointed I'm not dropping a rebuilt cobra engine in there....That would have been sweet. But for now, we'll see if replacing the stock manifold with a PI manifold fixes the problem.

Thanks again for the replies and any additional input is more than welcome. Keep in mind I'm fairly car illiterate and don't know much other than how to change my own oil. Always loved this car tho and I don't ever want to get rid of her.

 

yea +1 on swapping for a mach 1 or 03 or 04 cobra motor, even the NA 99 to 02 cobra motor would be cool.

 

I thought the cracked block seemed odd. But anyway, you can buy those new trick flow heads when they come out and be in the same boat without much hassle

 

I will tell ya this. When my Dodge ramcharger's 318 went out I contacted an engine builder, he qouted me a price on a 360 for my truck. I asked him about cams and pistons and boring the block, all that stuff is really cheap to do when the guy is putting it together, I got high compression pistons 10 to 1 (means high octane only) and big cam and a .30 bore for an extra 500 bucks. I went and bought my own edlebrock intake manifold (rpm airgap series -250 bucks) already had the 650 edle carb.

Long story short a lil leg work and 750 extra bucks got me a nice engine.

You could easily have an engine rebuilder bore out a block put some high comp forged pistons in there with a nice forged crank and maybe a lil head work too, you could have a 325hp+ motor for about a grand on top of the cost of the block.

 

IIRC, there was a recall on the plastic intakes on the 4.6's...

Here ya go :-)

https://mustangforums.com/forum/4-6-...-manifold.html

and

https://mustangforums.com/forum/4-6-...t-settled.html

So, odds are that it is just the intake.