Ok -- This is on an '04 Impala with a 3800 S/C.

Current Mods:
Comp Cams 1.9:1 roller rockers
Chromoly Pushrods
3" Downpipe, Hi-flo cat, U-Bend Delete
1-step colder plugs
WAI
3.4" Pulley
Intense Racing PCM


We are trying to install an intercooler on this car. We have tried numerous things with installing it and still have problems and no success thus far.

We first found out you need to block the coolant passage on the Lower Intake Manifold (where it would normall go through the TB) to prevent it from getting sucked into the motor. This is because there are not 2 holes in the core to provide for this.

We have those blocked off, and the car still will not run with the intercooler core on it. It will start and run for about 1/2 a second and die. If you give it gas, it will spit/sputter and backfire and then die.

There is no hole in the core for the PCV. While this escaped us before, we are curious if it would cause the car not to run. When you take the core off, and place the supercharger back on in stock location, it runs fine on the first crank. We have heard that if we were to take off the oil fil cap, that it would provide a breather hole for the crankcase, thus alleviating this problem.

We dont really want to take everything apart again if this doesnt sound like a viable solution to the problem. We would like to avoid drilling the core as well, specially if it will not work in the end.

Any insight would be greatly appreciated.

I dont want to subscribe to a 3800 forum just for this, and this site seems to have some of the best all around knowledge anyhow, so I came here first.

Again thanks!

Anyone know? crank case pressure vs. no start?

no pcv does help

ill post a link here and ask a few friends

whos intercooler core do you have ? and was the intercooler the only change before the no start or were the other mods done at the same time ? do you have any codes ? and d you have somethng to scan and tune the car with ?

1) Were all the mods listed installed at the same time?
2) What intercooler kit?




1989 Z24 Convertible - Dust Covered
2006 tC - Dust Covered, but driven more

Quote:

I would suspect a vacuum leak where the core meets the manifold. Need more info as to what intercooler he is using. And if it is an old style ZZP core without the PCV fix, he either must run a breather cap, or preferably run a hose from the oil fill cap to the intake between the MAF and the throttle blade.

this is the 1 reply so far

get back with some info asap

The mods listed besides the intercooler have been on the car for 2+ months with no problems.

It is an intense 1.95" intercooler core, the core is all that matters, the hose/pump/fmhe are seperate and havent yet been hooked up. The only holes in the core are the bypass hole, and the hole for the blower iteslf (aside from bolt holes). No PCV holes, No coolant holes.

Its a home made kit really.


Its not throwing any codes, just wont stay running, if you give it gas it sputters, and will idle like all hell and then die. The plugs have been changed since the coolant got into the motor.

I dont have any tuning software yet, HPT is comming when I get my government check. We have a scanguage hooked to it if that can be used at all.


Thanks for the replies so far!

here is what ive gotten

Quote:

Ok... It is one of two problems... Those cores openings are wider then the LIM opening by a fair amount. So much so, that there is almost no area between the intake manifold and core to get a proper seal with the gasket (less then 1/16" of overlapping surface area) there are there spots where this problem is, two on the front side of the LIM and one on the back side. It is highly reccomended that the LIM be removed, taken to a shop, and have about 3/8" of material welded to the outter part of the manifold to put more meat in these areas, and then have the area machined flat. This is also why ZZP IC cores have vacuum leak issues if you don't RTV them, the core plate is so thin on the bottom it doesn't seal well in those areas.

The other issue I have often seen on the Intense cores is that they develop coolant leaks easily where the heat exchanger is welded to the tank end on the snout side. If the leak is bad enough, it will cause starting/running issues.
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97cavy seems to be giving you some very solid info....sorry to hear about your problems, doesnt sound like an "easy" fix, but does sound like it is no sealing properly.

That was another issue we were thinking, that its not sealing properly somehow. We were thinking this because if the motor were to backfire and die (i forgot to mention this) -- that under the snout on the blower you would see a puff of blue smoke.

I really appreciate the info, yes its not something easy to deal with, but at least I can understand what the problem probably is.

Ill let my brother know what I read here and see what he wants to do.

I really appreciate the info guys, I told my bro that Jbody.org knows whats up, looks like I was right again

Thanks!