Boost Pressure

rs4mtnitro · **Posted:** Mon Sep 11, 2006 6:52 pm

I installed my boost guage to day and the highest it went was 14 psi. I thought I read some where it should go as high as 26 psi. Has any one seen more than 14 psi?

DarbyWalters · **Posted:** Mon Sep 11, 2006 6:55 pm

Probably only going to hit 23-24-25 at WOT under a load...probably in 3rd at speed...Might even not happen until the weather cools down ( maybe try it at night in the cooler air temps...ANYONE?

BIGPAPACRD · **Joined:** Wed May 10, 2006 11:25 pm **Posts:** 29

The highest I have ever gone or ever seen it was a little over 20. Almost seemed as if the psi was regulated to be at 20 so this is just a guess so please correct me if I am wrong.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

When the CRD was first released, there was an online blurb about it, with a quote from Jeep saying that the turbo was designed as a 26.5 psi system. If you are only seeing 14 psi under full load or WOT, something would seem amiss. You didn't say under what conditions, what pedal position or speed. It would help to have some additional information. For example

1. average boost at idle, when fully warmed up
2. average boost at 60, or 70 mph cruise
3. average boost on fast, prolonged wide open pedal acceleration.

If 14 psi is the answer to #3 above, it would seem something is amiss. I think Ripster might have put his gauges in, he may have some info on this. My gauges are still in the box - I want to get the recall tsb, the ball joint tsb and now the moaning rear, sticking burning brakes and burned axle seal which is leaking oil fixed before I put them in. Haven't been able to keep up with the seemingly endless stream of tsb flash updates.

My CRD had a condition called turbo bark from day one, and it stayed that way until the last flash update - along with reduced torque, the turbo bark disappeared. I suspect they lowered the boost to reduce the number of TC's from dying on them. Would be great if those who have had the boost gauges before the last couple of flashes applied could tell us if the boost dropped.

The update that eliminated my turbo bark and reduced power somewhat had this description and number on the paperwork:
"replaced egr valve and reprogrammed pcm with updated flash"

This label with this number was on the TCM, not ECM/PCM
56044562

rs4mtnitro · **Posted:** Mon Sep 11, 2006 9:43 pm

Ranger1 wrote:

When the CRD was first released, there was an online blurb about it, with a quote from Jeep saying that the turbo was designed as a 26.5 psi system. If you are only seeing 14 psi under full load or WOT, something would seem amiss. You didn't say under what conditions, what pedal position or speed. It would help to have some additional information. For example

1. average boost at idle, when fully warmed up
2. average boost at 60, or 70 mph cruise
3. average boost on fast, prolonged wide open pedal acceleration.

If 14 psi is the answer to #3 above, it would seem something is amiss.

It doesn't seem to matter what i do it won't go over 14 psi. Power braking, 0 to 80 WOT, all the same. At idle it is 0 psi

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Not good. A suggestion might be to disconnect your boost gauge from the intake manifold, cap your mounting stud, and hook your boost gague tubing to a known pressure source that you can measure with a digital tire gauge. Alternatively, use a temporary piece of boost hose to your intake connection point and measure it with a digital tire gauge adapted to your tubing with one of those tire pump adapters that will fill up a basketball. Once you verify that the boost gauge is reading correctly, reconnect and see whats happening. If its maxed at 14 PSI on WOT, its not correct. What is the latest flash you've had done on your CRD?

litton · **Posted:** Mon Sep 11, 2006 10:02 pm

Does the CRD have a waste gate? Can turbo pressure be released elsewhere in the system?

oldnavy · **Posted:** Mon Sep 11, 2006 10:03 pm

Ranger1 wrote:

The update that eliminated my turbo bark and reduced power somewhat had this description and number on the paperwork:
"replaced egr valve and reprogrammed pcm with updated flash"

This label with this number was on the TCM, not ECM/PCM
56044562

Had this same done to our CRD and on test drive with tech he squalled the tires about 20 feet leaving the dealership. I have only had it to 90 MPH since then but it was still climbing when I backed out of throttle.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Mine no longer has enough power to bark the tires after this last flash. Very gradual acceleration. My wife, who usually does not notice power levels on any vehicle we own, drove the CRD for the first time in several months yesterday and mentioned the lack of power compared to what it used to be. I see it was not my imagination after all.

DarbyWalters · **Posted:** Mon Sep 11, 2006 10:15 pm

No wastegate on the Turbo...the variable vanes controlled by a solenoid take the place of a "wastegate"...the pitch of the vanes controls the boost pressures essentially.

Joe Romas · **Posted:** Mon Sep 11, 2006 10:37 pm

litton wrote:

Does the CRD have a waste gate? Can turbo pressure be released elsewhere in the system?

I think it's a variable geometry turbo. Same company, Garrett, makes VW's and they've been using then since the NB TDI in 98 and the Jetta tdi since 99.5 The fins actually change angle to varie the turbo speed.

BIGPAPACRD · **Joined:** Wed May 10, 2006 11:25 pm **Posts:** 29

Ranger1 wrote:

1. average boost at idle, when fully warmed up
2. average boost at 60, or 70 mph cruise
3. average boost on fast, prolonged wide open pedal acceleration.

1. At idle I definitely see 0 psi. (Don't forget that you are not going to see much boost when you are sitting in park and rev the engine. Engine must have a load before you see any significant readings)

2. Average boost at 60 or 70 mph cruise I will see anywhere between 10 psi and 15 psi. This will vary and boost will increase as you go uphill, increasing the engine's load.

3. Average boost on fast, prolonged wide open pedal I will see anywhere between 20-25 psi.

rs4mtnitro · **Posted:** Tue Sep 12, 2006 9:27 pm

Ranger1 wrote:

Not good. A suggestion might be to disconnect your boost gauge from the intake manifold, cap your mounting stud, and hook your boost gague tubing to a known pressure source that you can measure with a digital tire gauge. Alternatively, use a temporary piece of boost hose to your intake connection point and measure it with a digital tire gauge adapted to your tubing with one of those tire pump adapters that will fill up a basketball. Once you verify that the boost gauge is reading correctly, reconnect and see whats happening. If its maxed at 14 PSI on WOT, its not correct. What is the latest flash you've had done on your CRD?

The last flash was the TCM in April and I won't let them do any more cause it sounds like the latest one is attempting to fix by depowering. I want more power not less.

MACKJ · **Posted:** Wed Sep 13, 2006 8:16 pm

rs4mtnitro wrote:

I installed my boost guage to day and the highest it went was 14 psi. I thought I read some where it should go as high as 26 psi. Has any one seen more than 14 psi?

I am looking at installing a boost gauge also.
How did you make the tap in for the boost line into the engine cover support as shown in the photos?
I checked under mine last night and there is no straight through hole into the inlet manifold.
Did you drill it out?

rs4mtnitro · **Posted:** Thu Sep 14, 2006 3:21 pm

I put in a vise on a drill press and drilled down and then laid it down and drilled and tapped the side. I used nylon washers and a vacuum when drilling the intake. Make sure you use a pipe thread tap. I stoll the idea from some one else on here.

MACKJ · **Posted:** Thu Sep 14, 2006 8:08 pm

rs4mtnitro wrote:

I put in a vise on a drill press and drilled down and then laid it down and drilled and tapped the side. I used nylon washers and a vacuum when drilling the intake. Make sure you use a pipe thread tap. I stoll the idea from some one else on here.

Thanks. I understand about the engine cover bolt...what size hole did you drill in the intake?
However I am a little concerned that the vacuum might not pick up all the metal as the drill breaks through into the manifold cavity!

rs4mtnitro · **Posted:** Thu Sep 14, 2006 8:21 pm

I drilled most of the way and stopped to vacuum then finished. The stud and intake were just under 1/8. A little aluminum in the intake never hurt anything.

n3qik · **Posted:** Sun Sep 17, 2006 11:57 am

rs4mtnitro wrote:

I put in a vise on a drill press and drilled down and then laid it down and drilled and tapped the side. I used nylon washers and a vacuum when drilling the intake. Make sure you use a pipe thread tap. I stoll the idea from some one else on here.

That would be me, Yes use the smallest bit you have for drilling in the intake and a little wax on the bit to grab the shavings helps also.

I see the same pressures as BIGPAPACRD has posted.

If you do check the calibration and it checks out fine, check on the passerger side fender. You will find a black device with some hoses to it. This is an electric vacume pump the is used to drive the turbo VGR valve. There is a small filter there check to see if it is clogged. Also check for loose/broken/pinched vacume lines.

rs4mtnitro · **Posted:** Sun Sep 17, 2006 7:21 pm

I hooked my CO2 tank to my gauge and found it wasn't reading right. The gauge was in a bind from mounting and prevented it from going higher than 14. I spent this afternoon fixing it and it now reads 20psi at WOT. Of course I made sure it worked all the way to 40psi with CO2.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Where did you find the brass fittings and coupler for the plastic tubing? My gauge came with a plastic tee intended for connection into an existing rubber hose. I'm assuming yours has a ferrell connection on the plastic line where it fits into the brass fitting.

Boost Pressure

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