Soot Level Rising Fast while driving 2014 Volvo 670 D13 What could it be?

Siinman · Oct 19, 2021

So update and fix for this issue was as follows:
1. Flex Pipe did have a leak in it even though they said they checked it the first time around.
2. DPF filter was clogged from the heat shielding wrapping. I would guess it was from the Flex Pipe hole cause it to Rott out from the heat. Got it baked and blown out and now everything works fine.

ontheway · Nov 11, 2023

loudtom said: ↑

The way I found out was to rule everything else out first. I had the DPF taken apart and cleaned just in case. It wasn't even close to plugged, so I moved to the EGR system next. I was getting high exhaust temperatures as my soot gauge was rising, and I think it was because the spring in the EGR valve was weak and allowed the valve to open under boost. I had it replaced, and everything went back to normal for about 800 miles. Then injector #2 went out, and the soot level started acting up again, although the exhaust temperatures stayed low, unlike with the EGR valve. There was also the noticeable misfire while the engine was running. Before I replaced the EGR valve, I was kind of hearing a misfire/rattle noise when I would lightly accelerate, so I think the injector was acting up all along, and I didn't know it was a problem until it went out for good.

What you can do to troubleshoot your EGR valve would be to take a rubber glove and put it around a pipe coming out of the EGR cooler. Then you disconnect the plug that powers the EGR valve so that it doesn't open when you turn on the truck. If you start the truck and the glove inflates, then you've got a leaking EGR valve.

The first time my soot gauge was acting up, it was because of plugged up ports on the venturi tube. In that instance, the turbo would not hold pressure steadily. It would bounce between 5 PSI up and down around where it should be, and you could hear the turbo kind of surging and lagging.

If your truck is completing a regen and the temperatures are within spec, then I probably wouldn't look at the 7th injector as a problem. I took mine off and cleaned it up and replaced the gasket, but I didn't expect it to fix anything. It's just something I do preventatively while the DPF was off getting cleaned. I think 2014 and up have an AHI module that controls the fuel pressure to the 7th injector. There are a couple of valves and springs in there that are susceptible to getting blocked up if you don't change your air dryer cartridge regularly. Since you're not having problems completing a regen, I don't think there's an issue here, but it's something you'll want to keep on top of.

I think exhaust or boost leaks might mess with your pressure sensor's readings. If the computer believes you're normally supposed to have 25 PSI, but you really have 20, then the differential pressure sensor on the DPF is going to interpret that as a 5 PSI restriction, or whatever it uses calculates that. It can work similarly with an exhaust leak. If any pressure is lost between the sensor and the engine, it will read that as a restriction. I had mine tested when I was troubleshooting my soot gauge. You'll usually notice worse power and fuel mileage, and sometimes a noise with a boost leak. Exhaust leaks will be soot around the affected area. Boost test will be pressurizing the intake system and spraying everything with soapy water, and exhaust test will be putting smoke into it and seeing where it comes out of.
Click to expand...

loudtom said: ↑

The way I found out was to rule everything else out first. I had the DPF taken apart and cleaned just in case. It wasn't even close to plugged, so I moved to the EGR system next. I was getting high exhaust temperatures as my soot gauge was rising, and I think it was because the spring in the EGR valve was weak and allowed the valve to open under boost. I had it replaced, and everything went back to normal for about 800 miles. Then injector #2 went out, and the soot level started acting up again, although the exhaust temperatures stayed low, unlike with the EGR valve. There was also the noticeable misfire while the engine was running. Before I replaced the EGR valve, I was kind of hearing a misfire/rattle noise when I would lightly accelerate, so I think the injector was acting up all along, and I didn't know it was a problem until it went out for good.

What you can do to troubleshoot your EGR valve would be to take a rubber glove and put it around a pipe coming out of the EGR cooler. Then you disconnect the plug that powers the EGR valve so that it doesn't open when you turn on the truck. If you start the truck and the glove inflates, then you've got a leaking EGR valve.

The first time my soot gauge was acting up, it was because of plugged up ports on the venturi tube. In that instance, the turbo would not hold pressure steadily. It would bounce between 5 PSI up and down around where it should be, and you could hear the turbo kind of surging and lagging.

If your truck is completing a regen and the temperatures are within spec, then I probably wouldn't look at the 7th injector as a problem. I took mine off and cleaned it up and replaced the gasket, but I didn't expect it to fix anything. It's just something I do preventatively while the DPF was off getting cleaned. I think 2014 and up have an AHI module that controls the fuel pressure to the 7th injector. There are a couple of valves and springs in there that are susceptible to getting blocked up if you don't change your air dryer cartridge regularly. Since you're not having problems completing a regen, I don't think there's an issue here, but it's something you'll want to keep on top of.

I think exhaust or boost leaks might mess with your pressure sensor's readings. If the computer believes you're normally supposed to have 25 PSI, but you really have 20, then the differential pressure sensor on the DPF is going to interpret that as a 5 PSI restriction, or whatever it uses calculates that. It can work similarly with an exhaust leak. If any pressure is lost between the sensor and the engine, it will read that as a restriction. I had mine tested when I was troubleshooting my soot gauge. You'll usually notice worse power and fuel mileage, and sometimes a noise with a boost leak. Exhaust leaks will be soot around the affected area. Boost test will be pressurizing the intake system and spraying everything with soapy water, and exhaust test will be putting smoke into it and seeing where it comes out of.
Click to expand...

Hi sir，very thanks for you share experience ，my volvo truck driving ，when soot level its low，I can hear noise like “tu tu tu” like boost leak，DPF soot raise very quick，when soot high，drive better，less “tu tu tu” and continue drive，soot level go down，repeat like this，when “tu tu tu ”happen，My turbo pressure bounce ，like you say about 5 psi up and down . I have replace TURBO KIT and EGR VALE，PIPE ，CLAMP，AIR VALE ，many parts，In your experience ，it shoube be venturi tube？Thanks！

ontheway · Nov 11, 2023

loudtom said: ↑

The way I found out was to rule everything else out first. I had the DPF taken apart and cleaned just in case. It wasn't even close to plugged, so I moved to the EGR system next. I was getting high exhaust temperatures as my soot gauge was rising, and I think it was because the spring in the EGR valve was weak and allowed the valve to open under boost. I had it replaced, and everything went back to normal for about 800 miles. Then injector #2 went out, and the soot level started acting up again, although the exhaust temperatures stayed low, unlike with the EGR valve. There was also the noticeable misfire while the engine was running. Before I replaced the EGR valve, I was kind of hearing a misfire/rattle noise when I would lightly accelerate, so I think the injector was acting up all along, and I didn't know it was a problem until it went out for good.

What you can do to troubleshoot your EGR valve would be to take a rubber glove and put it around a pipe coming out of the EGR cooler. Then you disconnect the plug that powers the EGR valve so that it doesn't open when you turn on the truck. If you start the truck and the glove inflates, then you've got a leaking EGR valve.

The first time my soot gauge was acting up, it was because of plugged up ports on the venturi tube. In that instance, the turbo would not hold pressure steadily. It would bounce between 5 PSI up and down around where it should be, and you could hear the turbo kind of surging and lagging.

If your truck is completing a regen and the temperatures are within spec, then I probably wouldn't look at the 7th injector as a problem. I took mine off and cleaned it up and replaced the gasket, but I didn't expect it to fix anything. It's just something I do preventatively while the DPF was off getting cleaned. I think 2014 and up have an AHI module that controls the fuel pressure to the 7th injector. There are a couple of valves and springs in there that are susceptible to getting blocked up if you don't change your air dryer cartridge regularly. Since you're not having problems completing a regen, I don't think there's an issue here, but it's something you'll want to keep on top of.

I think exhaust or boost leaks might mess with your pressure sensor's readings. If the computer believes you're normally supposed to have 25 PSI, but you really have 20, then the differential pressure sensor on the DPF is going to interpret that as a 5 PSI restriction, or whatever it uses calculates that. It can work similarly with an exhaust leak. If any pressure is lost between the sensor and the engine, it will read that as a restriction. I had mine tested when I was troubleshooting my soot gauge. You'll usually notice worse power and fuel mileage, and sometimes a noise with a boost leak. Exhaust leaks will be soot around the affected area. Boost test will be pressurizing the intake system and spraying everything with soapy water, and exhaust test will be putting smoke into it and seeing where it comes out of.
Click to expand...

Hi sir，very thanks for you share experience ，my volvo truck driving ，when soot level its low，I can hear noise like “tu tu tu” like boost leak，DPF soot raise very quick，when soot high，drive better，less “tu tu tu” and continue drive，soot level go down，repeat like this，when “tu tu tu ”happen，My turbo pressure bounce ，like you say about 5 psi up and down . I have replace TURBO KIT and EGR VALE，PIPE ，CLAMP，AIR VALE ，many parts，In your experience ，it shoube be venturi tube？Thanks！

loudtom · Nov 11, 2023

If you disconnect the sensor from the venturi pipe, you should be able to see if the ports are blocked up. You can buy a new one, or you can try to clean it out. To clean it, start with a pick to get the hole started. Then take a stranded wire or cable that can fit in the hole and attach it to a drill. When you run the drill, it should act like a wire brush that can curve around the corners. Just slowly work it in and out of the ports and it should finally break through. I used brake cleaner in short bursts to finish cleaning it up. I can't really guarantee that it will fix your problem, but it stopped my boost levels from bouncing up and down and the soot level stabilized.

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Soot Level Rising Fast while driving 2014 Volvo 670 D13 What could it be?

Siinman Road Train Member

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Soot Level Rising Fast while driving 2014 Volvo 670 D13 What could it be?

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