[danieljag1]

I have a 2000 Mustang GT with 147,000 miles and a manual tranny. Two days ago, my car began to sputter really bad unless over 2000 RPM. I figured it was condensation in my fuel lines because that has happened before. But today the CEL came on throwing a "cylinder 8 misfire" code. I had the same code a few months back, replaced the spark plugs no problem, but in the spark plug holes there was anti-freeze. I knew my intake must of had a crack, so I saw this coming. I just want to make sure I am not thinking of anything else besides the obvious (spark plugs, COPs, fuel filter, etc), I know all that. This just frustrates me because on my old Mustang, I had this same issue and spent over $400 trying to fix it, but i ended up selling it without ever finding a solution. I am just beginning to lose faith in Mustangs as good, stable cars. I love them, but it's hard to love something that doesn't love you back. Thanks guys!

 

[DJAlsip]

Well, obviously if your intake has a crack you have to replace it. The anti-freeze is coming from somewhere, so finding the root of the problem and fixing/replacing it should fix this. Your car does have a lot of miles on it, and since Mustangs tend to be driven harder than regular cars, you can only expect to encounter things here and there that needs to be fixed. I'm no expert, but shouldn't a compression test tell you if there are any leaks anywhere?

 

[danieljag1]

My Dad and I have attempted to run compression test before, but we were never able to get it hooked up right because the only two at the auto parts store around here were faulty. So I've given up on compression tests after 2 trips to autozone and 3 hours wasted trying. I just wanted to make sure replacing the manifold is a likely reason for the coolant leaks.

 

[wmburns]

+1 on DJAlsip.

The post does not mention if the manifold is the all plastic design or the updated version with the metal coolant crossover. If all plastic, almost certainly, the intake is your problem.

To get love, sometimes you have to give love. To me it's not a surprise that your Mustang has let you down since you continued to drive it with a known anti-freeze leak.

Note, Harborfreight sells a compression tester for $24. The tool is not very expensive. Or consider using a different autoparts store.

Quick-Connect Compression Tester

 

[danieljag1]

Yes it is the original stock intake. All plastic, I believe.

 

[DJAlsip]

Just curious, but aren't all 99-04 equipped with PI heads and PI Manifold? And if so, isn't the PI manifold supposed to have the metal coolent crossover? Or was that only the Romeo engines in 01-04 that had those?

 

[wmburns]

Just curious, but aren't all 99-04 equipped with PI heads and PI Manifold?

Yes all 99-04 Mustang GT's have PI heads and PI intake manifolds. 99-00 Mustang GT's have Windsor motors. 01-04 GT's have Romeo motors.

And if so, isn't the PI manifold supposed to have the metal coolent crossover?

No. The 99-00 Mustang came from the factory with an all plastic PI intake manifold. My 2000 GT did have an all plastic PI intake manifold.

 

[DJAlsip]

Okay, thank you! Just wanted to clear that up, both for me and others wondering.

 

[danieljag1]

Thanks for all the help guys! I ordered the FRPP Intake from AM last night. Anything you guys can recommend that I should buy for this project? Gaskets, thermostat, etc.? Those are just some things I've heard of people replacing at the same time as the intake.

 

[DJAlsip]

I would probably look into a new plenum and/or throttle body too if I were to change my intake manifold, just to see some gains in performance and throttle response.

 

[danieljag1]

That stuff is for later on after I fix critical problems. I meant like what gaskets do I need, how much coolant to buy, gasket cleaner, carb cleaner, etc.?

 

[DJAlsip]

A few simple searches on google will usually answer your questions. Example: 2003 Mustang GT Coolant Fluid.

I would imaging you would need a new gasket too for the intake manifold to keep it from sucking in hot air around the engine block though. I honestly don't have much knowledge on this as of now, so if anyone else want to chip in, feel free!