How to test intake manifold for leak

[RunMonkeyRun]

Hi guys, yes I am having problems with my 6.5 , I was having a vacuum pump issue which I have resolved except that I am still getting no boost pressure. I was at my mechanics today and I told him I wanted to check the boost pressure, well I am getting a vacuum to the wastegate and I no black smoke finally, we hooked his snapon up to the truck and it read o boost, wastgate was opening and the baro was at 101, when we gave it gass it dropped to 97-98, I thought barometric press was suppose to rise? yet boost still read 0, drove around with it hooked up to see if under load the boost would budge but didn't. I do hear some air from behind the fire wall when driving just wondering if maybe the intake is leaking somewhere. How do you check to see if this is possible? oh by the way we did change the map sensor or what ever you call it on top of the pleniom with same results.

[gmctd]

Engine at idle -

25" vacuum at the pump

15" vacuum at the wg

wg rod should be very difficult to move at idle

engine makes no or very little Boost at idle

Check the rubber connecting boot between the compressor and the upper intake plenum - might also see if that plenum is loose.

[RunMonkeyRun]

Now that I have changed the vacuum pump with the engine at idle I cannot push the wastegate down which is correct, I know what you mean about the rubber whcih is above my alternator, I will inspect that tomorrow seeing as there is alot of oil around it, well all over it. I have definetly good vacuum and wastegate is only a year old and the solenoid is only a year old aswell.

Oh plenium is tight.

[john8662]

While you're changing the boot between the turbo and the intake you'll remove the upper intake plenum. Inspect this gasket, it should get replaced when you remove it, it's possible its torn at one point, maybe on the back. It's happened to me.

J

[Bnave95]

Am I reading this right.
Have new Vac. pump yet you have no boost. Also can not move the waste gate rod at idle?

[RunMonkeyRun]

Am I reading this right.
Have new Vac. pump yet you have no boost. Also can not move the waste gate rod at idle?
Yesterday 10:25 PM

Yes thats correct except whem truck is running the wastegate lever goes up when running at idle and I try to push the rod down and it shouldn't go down, when I was checking the vacuum before I pretty much had no vacuum I was able to push the rod down at idle, meaning I now am getting good vacuum with the new vacuum pump, or am I just wrong on that issue.

[65TD]

No black smoke, vacuum good. Sounds like the turbo is working.

What's wrong besides the scanner reading?

Got any manual boost gauge?

[RunMonkeyRun]

I got zero boost, for some reason, I haven't had a chance to get at it I have been crazy at work and I need the stupid truck. Hopefully tomorrow I will get a chance at it. All the scanner said was under boost is 0.

[65TD]

Please verify that you said no black smoke now when accelerating.

Is this correct?

[Cowracer]

FYI, with the IAT sensor out (big freaking hole, bigger than 1/2") the truck will still make boost, but not full boost.

And it sounds like a train it going by. Unless you had the intake off recently, I wouldnt thing you have an intake leak.

I would check the donut gaskets on the crossover pipe. If one of those go, the turbo wont hardly have enought exhaust gas to make any boost, and you would hear something down on the firewall.

Tim

[RunMonkeyRun]

I was thinking that to Cowracer but I did have the pipe and new donuts gaskets put on, when the donut gaskets went I heard that air in the fire wall before so I will check it out again just in case they didn't install it properly.

[Bnave95]

FYI, with the IAT sensor out (big freaking hole, bigger than 1/2") the truck will still make boost, but not full boost.

And it sounds like a train it going by. Unless you had the intake off recently, I wouldnt thing you have an intake leak.

I would check the donut gaskets on the crossover pipe. If one of those go, the turbo wont hardly have enought exhaust gas to make any boost, and you would hear something down on the firewall.

Tim
This reminds me of back when GM did a long block R&R, before boost gauge and any mods they had left two of the six turbo manufold bolts out.

[RunMonkeyRun]

Apperently i have 2 codes coming from the scan 1217 and 1216?
I think the 1216 is fuel selinode cycle to short
But 1217 I don't know what that is.

I put a fsd cooler with a new pmd 6months ago thinking it might be the problem for the hot start issue, I put the new one still having the same problem, only way I could get the truck to start was to put luke warm water on the pump in order for it to start, now the it is cold in Toronto, Ontario I don't have the hot start problem.

So I am told that the injection pump has a problem and they want to pull it out, I am thinking of trying to some how plug the wires back into the pmd on the pump as it wasn't the problem before. Is it even possible or am I ripping the manifold off?

What do these codes have to do with boost pressure?

I suck at this and getting really frustrated!!!!!:confused:

Oh they also gave me this info

TDC + 1.2
c-time 1.9

I assume the tdc is timing and is off a bit. c-time apperently is within specs at 1.9

[65TD]

The TDC should be a negative number between -.5 and -1.94 for best performance.

That will cause starting issues when hot. When it's cold the timing is advanced by the PCM.

The timing needs to be adjusted.

[RunMonkeyRun]

Well thats what I thought but since I had got the injection pump 2 years ago I have had nothing but problems. This pump was brand new and has gone out of timing before a few times, well to make along story short I have it back at there shop because I am already pissed off enough to argue with them on this, I mean they know I have had nothing but problems since they have put this in and it just kills me that I cannot seem to find a decent mechanic shop. It is a work truck so its not like I can dilly dally around and fix it myself which I could but when the truck is down I lose money (which sucks) but I will see tomorrow what they say and go from there. I will post what happens.

[JohnC]

Just to throw my 2 cents in, if you have a working turbo and an intake leak big enough to syphon off all the pressure, your truck will sound like a cross between a screaming banshee and huricane Katrina. If it doesn't, look elsewhere....