uh oh!

[my98SVTturbo]

ok so i walk in my garage this morning and start up the SVT to move it out and i let it idle for a minute. well right before i was gettin ready to drive it out it starts vibrating and shaking really hard . so then i give it a lil gas to about 3-4000 rpms while it was in neutral and the next thing i know the rpms go almost down to 0 and reved it self up to about 2000rpms for like 20 seconeds constanly by its self. It felt like it was gonna stall and was saking/vibrating really bad. I felt like i was in a dump truck or sometihn cuz it was so shaky. Also i noticed the thermostat was on cold the whole time and wouldnt move up. so my question is what is this?

 

[Reebs]

The reving and stalling sounds like a sticky IAC that needs to be cleaned or replaced... however only buy a Ford OEM IAC (not the autozone crap!).

 

[FabioSVT]

I have the same problem, I replace IAC, EGR, MAF, I talked to a mechanic that works @ my bodyshop and we did a test on the manifold gaskets and there seems to be a minor leak in the upper, i'm goin to change the upper and lower but our ford parts dealership has the gaskets on backorder so when i get them i will let you know how it works, but i suggest IAC if thats not it check the gaskets