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04 6.0l no boost

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I have this 04 6.0 that I did an EGR cooler, oil cooler, 4 injectors in. I offered to clean the turbo while I'm in there, being my first time disassembling a 6.0 turbo I don't have a clue what Im doing. Lol. It ended up not being very dirty at all, so I just put it back together, I made the marks but they got wiped off somehow, so I lost those. I got it back together and it seemed fine. Now I got the truck running etc, its making no boost. I make at most 1 psi of boost. The boost test registers .4psi on the test. I checked everything I did other than removing the turbo again. What am I missing here?

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Verified map hose and nipple on intake manifold clear. No exhaust leaks that I can hear. Performed boost leak test with a boost tester, held air pressure. Replaced vgt solenoid with known good solenoid. While sitting in the bay, wide open throttling it, EBP sensor hit 45 psi at one point. Took out sensor and cleaned along with tube. No changes. Verified vanes are clear and move freely. Nothing is bound up inside turbo. No bearing play, no shaft movement at all in turbo. Still can't build more than 2 psi of boost.

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Have had a few lately with dirty maf sensors acting just like a plugged exhaust causing no - little boost as well as plugged/damaged converter may be causing it and high ebp will cause lack of boost. 

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Is this an early build 2004? If so it may have the EBP inferred program in the PCM. If that is the case you will need to verify the turbo has learned and or perform the turbo relearn procedure before going any further.

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At some points EBP hit 50 psi while wide open throttle. Idling it stays round 20 psi. I have removed the EBP sensor and cleaned the tube out with carb clean then stuffed a air gun in there to blow it out. I just did manifolds and up pipes a month before all of this work.

 

Milk Maid, it is built in April of 2004, I did not see any VGT learn pids.

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Also another thing, now got it to boost abput 10 psi. God knows how. But still lacking boost and power, also has a wooshing type noise like on/off. when accelerating on the road, so basically only with load on it. cant get it to do it standing still or even power braking. Sounds like a air leak type noise but I cant find any leaks. the up pipes are seated perfect far as I can see, none of the boots are torn/cracked/loose. I don't have a clue what im doing here...

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I just re-read your original post. Based on your information, it seems like you need to pull the turbo again to see what didn't go back together properly. It's very easy to misalign one of the vanes to the unison ring if you're green at this.

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I had pulled it back apart, and it all was ok. unison ring spins fine, the actuator rod in the turbo works fine, im gonna swap turbos with a yard truck and see if it changes anything. We don't have a diesel master tech here, and im a diesel rookie lol. I work on 6.7s and 7.3s... this is my first 6.0 job beyond a ficm or something simple. so I was sure I screwed something up. it didn't look like it, but who knows, at this point Im just gonna swap parts lol.

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Command vgt to around 50% and drive it. If you get good boost it's an input sensor issue. And plus 1 on disconnecting the down pipe at the converter. I had a cat that was busted up and caused some stupid boost issues.

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I figured out the VGT solenoid connector had 2 partially broken wires, might have been touching each other. And also the y pipe isn't sitting correctly.. the bottom of it is not flush. Any tips on aligning them? I have been prying on them but no luck getting it to align. If I pry on the turbo the bottom goes further away from the place it should be... I loosened them underneath but no luck still. It's quite shitty. Last time, when I did the up-pipes it took 3 guys with pry bars lol. any easier ways?

 

I hope this was all that is wrong.

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The proper procedure for the y-pipe is to loosen all connections. Seat the EGR cooler and turbo connections then hand tighten both clamps. Make sure the pipes are aligned at the manifolds with the bolts on loosely, then tighten the turbo clamp first then the egr cooler clamp, and lastly the exhaust manifold connections. If the turbo is seated correctly on the pedestal you should have no issues with this procedure.

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I have had luck loosening all the pedestal bolts, setting the turbo in place and moving the pedestal to fine tune y-pipe alignment. If it still won't line up then your going to have to loosen the whole pipe and reseat all connections. Hopefully the bellows are not twisted up from a previous repair

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Got the y pipe aligned, cant feel any more leaks... but still even after repairing that vgt solenoid connector, I don't have much of any boost. VGT commanded to 50% I still got nothing. MAP is reading 14.6psi, MGP is reading 5psi. Also, EBP is roughly 32-50 psi while vgt commanded at 50%

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That EBP is through the roof and the PCM should be opening those vanes to dump some of the exhaust pressure. Typically when I see EBP higher than desired a low VGT duty cycle will follow which will decrease pressure. 50% is right in the middle of the range of travel, the drivability will feel pretty normal and it may even overboost slighty around that range.

 

I'll never forget this 16k lb welding rig with a ZF-6 that had a unison ring frozen dead center in the swing range and that guy was so pissed off I cleaned his turbo because it never ran the same after that. Never mind I potentially saved his headgaskets.

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Your MAP sensor is not reading any pressure in the intake manifold, you should be getting some sort of code out of the PCM to indicate this. I would try to tackle one issue at a time here and put a low pressure gage in-line with the MAP signal hose, command the RPM to 1200, close the EGR valve, and ramp the VGT to 100% or as high as it will go. Then compare the reading on the gage with the MGP pid and see if they match. If they both show a measureable amount of boost but the MAP sensor still reads atmospheric pressure then................

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Matt, I cleaned the turbo, and made sure the unison ring is not frozen, I took off the metal cap and actuated by hand, moves very freely. So I don't think its that, and I hooked up a test light between the vgt solenoid pins and commanded up from 0% to 85%, at 20% is when the test light turned on full brightness and stayed there.

 

Milk Maid, I don't have a gauge to hook in-line. Unfortunately no one here does. I will work on finding something.

 

One thing that bothered me very much was that I noticed in a recording while driving that MAP was at atmospheric, BARO was at atmospheric, but MGP hit 6 psi at one point. I thought MGP was an inferred calculation based on MAP - BARO? How would the PCM be seeing 6psi of MGP but no changes in MAP or BARO. Makes no sense to me.

 

 

EDIT: Consistently, no codes. I would figure I'd see an underboost code while hammering it for a while and it knowing it has no boost... But nothing at all.

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Use regulated shop air on the MAP sensor and see what it does. The MGP issue almost sounds like a PCM calibration issue, maybe a PMI  on the PCM is in ordered here.

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Used shop air on the MAP, regulated between 20-30 psi, it kinda blipped up a few times but didn't stay. Checked the signal wire and found a break where it was opening intermittently. Spliced in new section of wire and its all set. Thank you guys I feel like an idiot because it was so damn simple.. I also updated the PCM calibration. Runs and drives beautifully now. 

Thank you to everyone here!

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