E350cdi howling around the turbo,egr.
02-17-2023, 05:58 PM
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e350cdi
E350cdi howling around the turbo,egr.
Hello there,I have developed a howling noise in the vicinity of the turbo egr valve ,e l light on ,plugged it in just showing egr fault. I fitted new egr valve cleared the light but the engine is still running in limp mode with no boost,under acceleration the howling siren like noise gets louder but the car doesn’t respond to the amount of noise it’s making. I can’t see any signs of leaks and I’m pretty sure the turbos boosting but something is restricting it and that’s the noise you can hear. Anyone with any ideas would be gratefully received.
02-18-2023, 08:02 PM
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I'm not a diesel guy but I assume you have a vacuum pump? And a solenoid that controls the turbos? If you trip an EGR code then it may kill the turbo. Or limp mode will for sure. I don't know why EGR would trigger limp mode...
So with the code, and assuming vacuum controlled turbo turned off by the ECU, then you have basically no boost but also no turbo whine. I'm assuming the noise you mentioned is turbo whine? As in you're familiar with it on this engine or just guessing and maybe it's some other noise?
If you have the assumed vac pump then I also assume you have a vacuum controlled EGR, which no doubt has a solenoid somewhere in the vac line. With a gas eng it's easy to tell if the EGR is working, you can hear the eng respond when it opens/closes. You can also manually activate the EGR so you can note exactly how the eng responds to compare if it's doing so normally. I do that by bypassing the solenoid and feeding it straight vac, or just plug a spare vac line into the EGR and suck on it. I'm reluctant to admit that on a public forum
I can't say if you'll notice a change on a diesel but worth a shot.
You replaced the EGR valve so I assume it's not leaking. If not leaking I can assume no exhaust leak sounds from it. I'd still check for whatever is making the noise because if the turbo is off then wth? So it makes me think there may be a different leak that you've been assuming is turbo whine? I dunno, I'm just guessing because there is some noise from somewhere, but no power.
It could also be an intake leak. The turbo is fine but it's just dumping all that boost, which you can hear. So I'd check the hoses and hose clamps on the tubing between turbo and intake. If all your boost is gone then I suspect a large leak, like a hose popped off. Maybe sitting there looking as if it's in place, but just barely. If it were an intake gasket of some sort I'd assume only a partial boost loss but possibly lots of noise, especially if it's using the gasket like a reed. Unlikely it happened the same moment the EGR failed, but maybe the leak caused the ECU to think the EGR is bad when it is not. ECU's are, imo, just shy of useless for detecting issues but excellent at claiming issues that don't exist. So look at a code as "maybe" and nothing more.
Aside from a lot of speculation on an engine I know next to nothing about, there is still some useful info to help troubleshoot.
Eg; leaks, which you mentioned, but what about under load when it's making said noise? The turbo hoses/clamps etc. Verify the EGR is in fact opening/closing. Try forcing the EGR open/closed.
If the ECU won't give you boost because of the EGR code, then I suppose clear it, then start it and floor it right away to get boost before you get a code. On a gas eng it'll detect EGR at idle so it could fault very quickly. Also be sure it's actually clearing the code because some codes are more difficult to clear and a cheap scanner tool may say it did, but a rescan shows it did not.
Or if the EGR solenoid is bad it may be detecting that, and I assume the same solenoid is still in there? But again, limp mode? Or maybe not limp, but instead it's that boost leak.
The vacuum to the turbos; is it getting to the wastegate and closing it? Check to see if the turbo solenoid is getting vacuum, the solenoid is working and none of the lines are leaking. If your vacuum pump is like mine, they have a check valve for the turbo and that check valve fails over time and your boost goes with it. I can send a pix of it if you need. When they fail they can pump oil into the vac lines, so check for that too. If the vac lines fill with oil it'll cause the turbo to work very slowly. If the canister fills it's even worse.
I think I'd start with double checking the code is clearing, and how quickly it returns. Say it returns before you even start it then I'd assume the ECU thinks the solenoid is bad. Some apps, like Torque Pro, should be able to tell you if the turbo solenoid is being commanded on or not. You can feel it because the solenoid is basically buzzing as it cycles on/off very quickly. The problem is it still buzzes when the ECU commands it off. So you can check to see how much vacuum you get on the turbo side because if off it'll be virtually none. The app should tell you what the ECU is commanding, in the form of 0-100% duty cycle, which in reality is likely 10-90% for whatever reason.
Post any other helpful info and replies to my speculations so we have more to go on.
So with the code, and assuming vacuum controlled turbo turned off by the ECU, then you have basically no boost but also no turbo whine. I'm assuming the noise you mentioned is turbo whine? As in you're familiar with it on this engine or just guessing and maybe it's some other noise?
If you have the assumed vac pump then I also assume you have a vacuum controlled EGR, which no doubt has a solenoid somewhere in the vac line. With a gas eng it's easy to tell if the EGR is working, you can hear the eng respond when it opens/closes. You can also manually activate the EGR so you can note exactly how the eng responds to compare if it's doing so normally. I do that by bypassing the solenoid and feeding it straight vac, or just plug a spare vac line into the EGR and suck on it. I'm reluctant to admit that on a public forum
I can't say if you'll notice a change on a diesel but worth a shot.You replaced the EGR valve so I assume it's not leaking. If not leaking I can assume no exhaust leak sounds from it. I'd still check for whatever is making the noise because if the turbo is off then wth? So it makes me think there may be a different leak that you've been assuming is turbo whine? I dunno, I'm just guessing because there is some noise from somewhere, but no power.
It could also be an intake leak. The turbo is fine but it's just dumping all that boost, which you can hear. So I'd check the hoses and hose clamps on the tubing between turbo and intake. If all your boost is gone then I suspect a large leak, like a hose popped off. Maybe sitting there looking as if it's in place, but just barely. If it were an intake gasket of some sort I'd assume only a partial boost loss but possibly lots of noise, especially if it's using the gasket like a reed. Unlikely it happened the same moment the EGR failed, but maybe the leak caused the ECU to think the EGR is bad when it is not. ECU's are, imo, just shy of useless for detecting issues but excellent at claiming issues that don't exist. So look at a code as "maybe" and nothing more.
Aside from a lot of speculation on an engine I know next to nothing about, there is still some useful info to help troubleshoot.
Eg; leaks, which you mentioned, but what about under load when it's making said noise? The turbo hoses/clamps etc. Verify the EGR is in fact opening/closing. Try forcing the EGR open/closed.
If the ECU won't give you boost because of the EGR code, then I suppose clear it, then start it and floor it right away to get boost before you get a code. On a gas eng it'll detect EGR at idle so it could fault very quickly. Also be sure it's actually clearing the code because some codes are more difficult to clear and a cheap scanner tool may say it did, but a rescan shows it did not.
Or if the EGR solenoid is bad it may be detecting that, and I assume the same solenoid is still in there? But again, limp mode? Or maybe not limp, but instead it's that boost leak.
The vacuum to the turbos; is it getting to the wastegate and closing it? Check to see if the turbo solenoid is getting vacuum, the solenoid is working and none of the lines are leaking. If your vacuum pump is like mine, they have a check valve for the turbo and that check valve fails over time and your boost goes with it. I can send a pix of it if you need. When they fail they can pump oil into the vac lines, so check for that too. If the vac lines fill with oil it'll cause the turbo to work very slowly. If the canister fills it's even worse.
I think I'd start with double checking the code is clearing, and how quickly it returns. Say it returns before you even start it then I'd assume the ECU thinks the solenoid is bad. Some apps, like Torque Pro, should be able to tell you if the turbo solenoid is being commanded on or not. You can feel it because the solenoid is basically buzzing as it cycles on/off very quickly. The problem is it still buzzes when the ECU commands it off. So you can check to see how much vacuum you get on the turbo side because if off it'll be virtually none. The app should tell you what the ECU is commanding, in the form of 0-100% duty cycle, which in reality is likely 10-90% for whatever reason.
Post any other helpful info and replies to my speculations so we have more to go on.
02-19-2023, 02:35 PM
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Hi Chevota .thanks for your reply , after attempting clearing the code again today Answering a few of your suggestions there’s no exhaust leaks, no black smoke-the waste-gate and egr are electric ( no vacuum pipes) I operated the waste-gate actuator via my computer and as it operated the engine note changed I’m just wondering if there is a pressure sensor in the boosted air side that if there is a split in the intercooler or pipes it would derate the engine. The engine is running on all six cylinders it’s just as if it’s a badly blocked fuel filter starving the engine and this howling noise,if I can work out how to send an attachment i will.regards,steve..
02-19-2023, 08:42 PM
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Interesting it's electric. I thought that was old school and they all used vacuum now, but what do I know
I recall seeing a video of a diesel car with a throttle, no doubt for emissions, and the vid was about it being defective and not moving. So if you have one I suppose it may be stuck and not opening?
There should be a pressure sensor somewhere or it won't know how to control the wastegate.
Yes, a ruptured intercooler, I forgot about that. I guess you could blow smoke into it and see if any comes out anywhere. Buy a pack of **** I'm in the US so that's entertaining for me, and from your text I imagine you're in the UK?
And/or I guess you need to find out why that EGR is throwing a code and hopefully that fixes everything. EGR passageways get blocked with carbon, if you're aware, so I don't suppose you looked inside when it was off? Just seems weird it would go into limp if the EGR was bad, but equally weird the EGR code would pop up for a boost leak... But the cars have to make guesses at determining what is bad so it's common, imo, for them to guess wrong.
I recall seeing a video of a diesel car with a throttle, no doubt for emissions, and the vid was about it being defective and not moving. So if you have one I suppose it may be stuck and not opening?
There should be a pressure sensor somewhere or it won't know how to control the wastegate.
Yes, a ruptured intercooler, I forgot about that. I guess you could blow smoke into it and see if any comes out anywhere. Buy a pack of ****
I'm in the US so that's entertaining for me, and from your text I imagine you're in the UK?And/or I guess you need to find out why that EGR is throwing a code and hopefully that fixes everything. EGR passageways get blocked with carbon, if you're aware, so I don't suppose you looked inside when it was off? Just seems weird it would go into limp if the EGR was bad, but equally weird the EGR code would pop up for a boost leak... But the cars have to make guesses at determining what is bad so it's common, imo, for them to guess wrong.
