Okay heres my question and problem. When my car is at full operating temps the idle gets crazy and holds steddy at 2,500-3,000RPM's?? When she is cold it idles fine..Like 800rpm's. I cant figuire this out, but when I take off the charge pipe to the trottle boddy the iddle drops to normal. I put it back on and the rpm jumps back to 2,5-3k. Do you think its a faulty waste gate or diaphram or if it falls along with this..I had it diagnosed yesterday that the head gasket is blown inbetween cylinders 2 and 3, and the rings in cylinder 2 are bad. The lifters are either carboned up or are bent in some way causing a small pressure leak. Not too much though. I will Start to tear the motor out sometime today and get it on a engine stand. While im at buying the rebuild parts I want to know if its worth it and safe to say my wastegate is bad and get a new one or junk the T25 and get the 14b? The idle for some reason is caused by the turbo and it building boost at idl causing the idle to raise? Since the haed gasket is blown would that cause a faulty reading in vacume lines and make the wastgate close to build boost, there for causing the high idle?? I got to get this car going soon, in like a month because i leave for college in arizona. I have the money and resources to get this done, what I want to know is whats the best head gasket out there that can take the punishment we throw at our 4g63t's ?? Ill get the basic oem gaskets for the engine accesories and some new 85.5mm Ross pistons and rings(stock).. And I was thinking of the head gasket from MachV.. Is that a good one? http://www.machv.com/cohega4g.html
And these are the pistons http://www.maperformance.com/dsm-eng...-pistons-ross/any way for the most part I want to know if the idle thing i was talking about sounds right or am I way off course? Thanks fellas and look forward to the help soon..

 

Do a boost leak test (1). Your IAC is dead (indicatation with warm motor and flexing idle) (2). BISS is leaking (3). Look at changing out the vacuum hoses (including EGR lines) (4). Look at changing TB gaskets (all of them) (5).

Motor issue:
Check your timing (5 deg TDC). Change head gasket with 4 metal layer type (Cometic, like MachV link) and go ahead and get ARP head studs while you're in there. Don't forget third gen 4g63 lifters (tick-free type). Look down into the cylinders with the plugs off and check for dings on the pistons.
Since you have the money and resources to do it, just get the motor rebuilt now before you head out! Skip the 14b and go with a EVO3 16G (don't forget fuel upgrade...check FAQ section in here, just above the 2G forum). Get new valves, lifters, springs, blah, blah, blahs. Do it right the first time and while you can. College studies will eat up 99.9% of your time, unless you party 99.9% instead.
Good luck bro.

 

Well I got the motor out on Friday. Took me about 4 hours. I even followed al the directions this time in my Chiltons book,lol... I never do that.. Any way, what my mechanic said for the diagnosis, he was way off. The head gasket was fine, the piston rings were perfect and the cylinder walls are good too. All valves are sealing properly except for the 1st exhaust valve in cylinder#2, where all the problems were comeing from. The valve has a big chip in the corner of it. Its about 1/8th of inch big. And the head stud that was near that cylinder was full of the blackest stinkiest oil i have ever witnessed. I mean it was bad. Why would that be?? Here is a link to where you can veiw the pic, its kinda small but you can see it. http://i388.photobucket.com/albums/o...er16/valve.jpg
So do you think that this will cause that crazy idle problem, etc??? Any way I also wanted to know if it was a big deal to just have the head cleaned up and just replace that valve with a oem valve, or have all of them replaced?? Thanks guys

 

How did the motor sound before you took it apart? Did the corresponding piston have a ding on it?
As for the head, replace all the valves, not just one or you will have to go back in later (1). Forget the valve and have the head checked, cleaned, and rebuilt with new OEM parts (2).

 

No, all the pistons looked like pistons,lol..No dings at all. The motor surprizingly sounded good, like a 4g63t should. I droped the head off today and the machinest said the valves look good and that I should just buy that new exhaust valve. He said he would "grind" down the other valves, I guess for cleaning the carbon build up or something? He is going to do a full rebuild and pressure test on the head, then do a good cleaning and Hot Tanking service for me and then put it back together. He's charging me $260 for it all. I should get my full Ajusa Gasket Kit tomorrow or thursday, the machine guy needs the new Valve stem seals that come in the kit to finish my cylinderhead. Yesterday and today I have been cleaning the motor real good with degreaser and pressure washer, and painted the engine block silver with 1500 degree paint and all the coolant pipes, engine brackets for miscelaneouse things all black. Looks sweet as hell. I had the valve cover and oil pan sandblasted and powder coated glossy black. Then last night i met this guy with a 1g tsi talon that had a bunch of things laying around. I picked up a 14b turbo(NOOOO SHAFT PLAY), 1g bov, 450cc injectors and a Eprom 2g tsi ecu for $125.. I know I should get the 16g, but the 14b will be good enough for street driving in Pheonix, and I got it for next to nothing. You cant beat that. I was hoping he had a 1g head but he had no engines or things like that. Anyway I should have the motor put back together for the most part and installed by next week? I took off that belt thats behind the timing belt to replace it and broke it in the process, it was that worn out. But the parts dealer for mitsubshi said that i prolly messed up the timing for it, and needs to be right. I have no clue how to do that, its not in the chiltons book. Any ideas on this stuff? Thanks peeps

 

honestly, when you change a part like a valve, its cheaper in the long run to just change them all. who knows when the next one will need replacing. its "cheap insurance". its kind of like changing one spark plug wire. why change one when you can get them all done and be done with it.

 

I see where your coming from. And your right its cheap insurance. I do have a question tho on my original vac problem. Now that i found what the problem with my car was, it being the valve. If you remember the origan post and my idle problem being at 3k. Would that valve cause that. It was making the turbo spool up on idle, thus causing the high idle? And on my 14b 1g turbo, i was testing the waste gate to make sure it works properly. The wg dont open up no mre then maybe 1/2 inch. Is that how the 1g's work, or is it faulty? It is kinda rusty. If its bad, can i use my t25 wg? Any way, i actualy just got my gasket kit and Arp studs, so I am going to drop off those valve guides to the machine dude. Lets see some input on my original idle prob??? Thanks guys

 

I would get the head rebuilt w/ all new valves, the only thing that worries me is where did that chunk of valve go?

 

The machining guy said that the valve didnt break off, it simply just burned a hole in it. "SIMPLY"..lol.. Well heres some updates to how the motor is coming back together. Its just about all together except for the new blts like the ac,ps and altenator. I put the new balance shaft belt on and the new mitsubishi timing belt on today also. The only thing that I think might be questionable is when I lined up all the time marks for the timing belt, and put it on the timing marks dont match up exactly like you would think. The cams are lined up, balance shaft and crank markings are off about maybe 1/16th of an inch. Me and my buddy took it off and tried again to better line it up but the same exact thing happens. If i jupm a tooth somewhere then it will be way more off no matter what. Is this normal? Anyway im going to a movie with my girl and when I get back then ill start on the engine install. Whats a good way to fill the oil and coolant that way it properly fills the turbo and all the other things so i dont **** nothing up??? Thanks guys

 

Crank it by hand first! Don't crank it as you would starting the car. Take the belt off and put it back on several times if you have to, but get the valves and crank aligned correctly or the work put into it now will just be a waste of time. You want to do it by hand so that you can feel it hit before it does any damage.