X loves the cold, hates it warm

[Repoman]

Well got the new y-pipe in this morning and got it all back together. On initial start up, lots of stumbling like usual but it seemed to get better as I let it idle. It idled for a few minutes w/o stumble then I took it for a quick run around the block and still seemed fine. Put it back in driveway for 15 minutes and started again, no stumbling. Backed out of driveway and put it in D, as soon as I touched gas pedal I got some minor stumbling but it went away again. Do I need to reset anything after doing this. It seems much better but still lurking. Or will the computer correct itself after a few miles? I cleared all codes and will drive for a while to see if they come back.

On another note, doing this repair showed me that I have a valve cover/valve cover gasket issue and also while underneath I saw a few chunks of grease on lower control arm so it appears that my driver side boot is giving way. First one at 55K, second one just short of 65K.

[c0rnfl4k3]

So what was the verdict on the DISA valve?

I'm here in Houston too and have been having a boatload of trouble since it's started warming up... I've got the 1800-2000RPM whistling, misfire codes, crap acceleration and rough idle on my '02 3.0i... I've checked the boot and that looks kosher, so I'm leaning towards the DISA or a MAF that is going out.

[Repoman]

Originally Posted by c0rnfl4k3

So what was the verdict on the DISA valve?

I'm here in Houston too and have been having a boatload of trouble since it's started warming up... I've got the 1800-2000RPM whistling, misfire codes, crap acceleration and rough idle on my '02 3.0i... I've checked the boot and that looks kosher, so I'm leaning towards the DISA or a MAF that is going out.

PM sent

Well I got the new boot on there and repaired the DISA valve but really didn't have a chance to drive it before I discovered fails with a window regulator, front cv boot and valve cover at the same time. I had it in my garage for a week waiting on regulator part. Got the window fixed, now waiting on new half shaft assy and pricing a valve cover/gasket now. I have driven a few times since and same old crap . . . just like what you've got. Misfire codes, rough idle, crap acceleration and still a whistle.

Evidently I've still got a vacuum leak evidenced by the whistle . . . probably around that crappy seal on the DISA valve. Sounds like you've got a vacuum leak too. I wanted to get that fixed first before I started spending more money on hard parts. I was thinking of doing one of those smoke tests because I've been through every other hose on the damn thing and didn't see any problems.

[Penguin]

Originally Posted by Repoman

Evidently I've still got a vacuum leak evidenced by the whistle . . . probably around that crappy seal on the DISA valve. Sounds like you've got a vacuum leak too. I wanted to get that fixed first before I started spending more money on hard parts. I was thinking of doing one of those smoke tests because I've been through every other hose on the damn thing and didn't see any problems.

One method of finding vacuum leaks is to use some WD40 spray or an unlit propane torch. You selectively spray the WD40 around possible vacuum leak areas, or hold the unlit propane torch nozzle, and if there is a leak in the area, you should hear a change in the engine speed when it sucks some of the WD40 or propane gas into the intake system.

Of course, since the vacuum leak you are looking for is after the MAF, do not spray WD40 into the intake system ahead of the MAF, as it could potentially foul the MAF.

And yes, I know this is a shade tree method and that hooking it up to a smoke machine is better, but this is a cheap alternative method that typically is quite successful in finding leaks.

[Mikedd]

Vacuum leak somewhere on the intake side or idle control valve. Sealed when cold and as it warms up becomes more pronounced? Check your oil separator hoses, they could be mush back there. My .02

[Repoman]

I have suspected that my oil seperator has crapped out. How strong should the vacuum be when you pull the oil cap? It seems pretty strong to me.

[MPDano]

So, what happened here? Was it the Disa and Hose that fixed your issue?