13 replies to this topic

[Snabb T5M]

So I'm at the dyno shop and we discovered a small hole in the intercooler. Its in the bottom part under the car, the black plastic piece(?). Going to JB Weld it and see what happens. Now have reason for a FMIC.

[Mesoam]

its supposed to be there

that is a weep hole for blow by

rich (bay13) used to recommend taping absorbent pads into the splash shield

only plug it if you're planning on running a catch can

[randomdude]

^that. its there for a reason.

[Fake-R]

What happens is it's plugged, without the catch can?

[ajhehr]

the universe will grind to a stop...





youll just get allot of oil/condensation buildup in the bottom from the higher mile turbos. and the PCV system.

[Snabb T5M]

What if the motor has been rebuilt, and the PCV is new? My motor builder told me to leave the plug in, should be fine.

ajhehr, on 18 September 2009 - 08:19 PM, said:

the universe will grind to a stop...

youll just get allot of oil/condensation buildup in the bottom from the higher mile turbos. and the PCV system.

[ajhehr]

leroystew, on 18 September 2009 - 09:41 PM, said:

What if the motor has been rebuilt, and the PCV is new? My motor builder told me to leave the plug in, should be fine.

im sorry, maybe i misunderstood... why did you start this thread? just to tell us that you were going to plug it?

yes it will be fine.

[mikeR]

I too found this once while looking for a lean code. It seems that it is a calibrated leak, since when the engine is under vacuum, some air could be sucked in and bypassed from the maf sensor. And while under boost, an obvious leak for pressure. When I saw this like a year ago, i plugged it, but maybe i should redrill the hole since i do not have a catch can. Its a 200K mile engine with new 16t and new pcv. hmmmm...

[Che'_Moderator]

It should be there on any IC. Its not just for blow by but also for moisture that condense on the inside of the IC.

[Snabb T5M]

Note: please read carefully, lots of questions in this post.

Ok, here's something weird with that IC hole. The hole was sealed with JB Weld; I went to the drag strip and on my first run everything was fine until I got into 3rd gear, in 3rd gear with maximum boost of like 16, 17 or more psi (didn't have a chance to look at the gauge), the car started misfiring and fell on its face for a second or two and the CEL came on. So I immediately thought the car was boosting too much and thus the misfires (running lean). I was able to remove the JB Weld from covering the hole, and the car was fine for the other 6 passes.

So at the dyno shop today, both the torgue curve and boost curve were up and down and not holding steady. The dyno shop said it may be a boost leak somewhere and so they pressure tested it and found the hole. I'm still waiting for the dyno shop to email me the graphs so I can post them. Now it makes me wonder is it this hole causing the torque/boost ups and downs or is it the IPD ECU doing it? The dyno shop uses a DynaPack and ran the car in 4th gear for the pulls. Do FMIC have similar holes for air to leak from? I understand the purpose of the hole, but shouldn't turbo systems not have leaks in them? It makes me wonder if I were to patch the hole again, or get a FMIC, then I most likely would need seem some sort of boost controller to turn the boost down a hair so the car isn't misfiring.

Che, on 18 September 2009 - 11:58 PM, said:

It should be there on any IC. Its not just for blow by but also for moisture that condense on the inside of the IC.

[Che'_Moderator]

Here is a hint. Its not that hole

[Snabb T5M]

Ok, will look elsewhere for the problem.

Che, on 19 September 2009 - 12:04 PM, said:

Here is a hint. Its not that hole

[Snabb T5M]

What else might cause the torque and boost curves to go up and down under boost/WOT? When the pressure test was done, the only leak we heard was from the IC hole that is supposed to be there. Still waiting for the charts from the dyno shop.

Che, on 19 September 2009 - 12:04 PM, said:

Here is a hint. Its not that hole

[Che'_Moderator]

leroystew, on 21 September 2009 - 02:37 AM, said:

What else might cause the torque and boost curves to go up and down under boost/WOT? When the pressure test was done, the only leak we heard was from the IC hole that is supposed to be there. Still waiting for the charts from the dyno shop.

Timing pull.