New Car parts aren't always good Car parts! 

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best auto diagnostic channel on RU-vid. dan has such a gift and talent to explain complex problems of car into simple easy to understand concepts. we love you dan, you're our superhero!

"But since we're not guessing but diagnosing" And that's why I love this channel -- and I'm not in the automotive industry. This is such a basic skill that is lacking in so many industries these days.

2:54 ~200C* (392F*) is the start temperature in some DPF temp sensors as the tarket temp for soot burn is at ~600c* (1112F*) That is if your car dont have system that lowers the burning temp of the soot. So never ever park your car that Has DPF in high grass!!!!! ...or you may have just started a fire that may cost more then your car. 3:43 It can also take messure from front of the cat (folowed by DPF) and the secon mesure point can be just atmosphere. That means the hole Exhaust backpressure is taken in your calculation. And so the fault can be in other part of the exhaust system. + if you cant see too mutch pressure in park then take it to safe plase to takerun at it. In secend gear from 1000rpm WOT to close to the red line. Then stop and take a look at the beak pressure. No turbo 4-cylinder engine max is usually ~150mbar with turbo 4-cylinder engine max is usually ~250mbar What i have seen car bean happy. No V-engines yet as these are more on Diesel exept they are comeing for petrol ass well here soon and alloso i live in Finland where thers no too much V-engines anyway. If you have Vacuum/pressure hand pump with gauge you can test its ok with your vacuum/pressure tester and when you know the ballpark in your hand pump then test the cars pressure tester and look at your data on scantool. Dont but more then 500mbar (0,5bar) to it as it can couse damage to the DPF sensor... Allso make sure to hook the lines back in rigth order! ...Some customers comes to us that have car that has new DPF and now its diffrent code then before. Well ofcorse as it cant see the backpressure if its backwards... I mostly wash them(water + soot removal product and time lots of time to dry folowed by full regenaration job) as they are mechanical filters anyway that means that the filter holes are so tiny that soot cant come out and there is no cemical reaction needed like in CATs that do the cleaning job and kill them self in process. 18:05 As DPF gets hot, those temp sensors gets stock (rememper what temp sensor is and how its made) as you turn them off you 90% of time Break them or shorthen the life time. So DO NOT do wash job with maschine that hooks in them in the car(if you dont want to install new sensor allso) allways take the DPF out of the exhaust system and wash it from back to front so shoot gomes out the way it come in from... Allso Know your DPF system example Ford use on some engine models a system that sprays extra fuel in exhaust pipe if that glow plug/ fuelnosel is broken then it will come back with full of sooth as it cant start the regenaration and no mostlikely there is no other code for some grat reason unknown... These are just my points and NO all isnt made the same so take it with grain of solt! Nice video man you earned a sub! Have a great week end! Cheers Timppa

Dan is no "parts changer" . A real mechanic. What all technicians should aspire to be.

Great video as always Dan , the Metal inside the DPF is most likely from the diesel oxidation catalyst in front of the DPF monolith .

That camera had great definition and it's ability to swivel was excellent too. Great thorough diagnostic work on that faulty component. When other workshops are sending you work it's because they recognise and respect your capabilities and professionalism.

Really good and informative video! More diesel videos for us diesel-driving europeans please

I like the fact that you had an Old-school manometer to confirm the readings from the engine management system and that you didn't rule out a professional clean of the DPF as opposed to always going for a new one. The multitude of problems that lead to blocked DPF is mind boggling, from a simple out of Calibration exhaust gas temperature sensor, to the obvious turbo oil seals . One of the most overlooked causes is EGR cooler leaks and the owner keeps topping up the coolant without getting it repaired in time. Keep up the good work 👍

THERMOSTATS---- I'VE FOUND THAT AT LEAST 30% OF THEM ARE BAD WHEN NEW so test every one before install.

Hi I've learnt a lot from this video great stuff. I've been very fortunate over the past 3 years to be given the responsibility of these dpf issues and can facilitate a clean. I can honestly say I've never had a dpf never work after a clean on the carbon clean machine and would highly recommend it to all technicians. So it brought to my attention and the end of the video does clearly show that the fact the aftermarket filter was poor. In my experience I would never recommend after market ones even if they are a lot cheaper. The reason being is that the plates inside are not as good as genuine plates, the reaction is either too poor or not sufficient in order to burn of all the soot/ash. Also depending on manufacturer the computer is would of been 0 in with the genuine part so when you install a after market system on, the ecu will not be understanding why it hasn't got a good regen, and mostly newer cars are clever enough to know what readings to have but also at differnet times in a regen. The camera is handy to inspect to see if its obviously blocked but to answer the question if this ones was blocked visually, unfortunately you cannot determine it my looking at the channels. Most dpf will block at the top and can show the channels decrease in size. But some have been blocked further in the system and there is no way of telling as the holes are so thin. I would then refer back to the clean as it is cheap and worth a attempt to see if it clears it out. This is just my advice and I've done loads to know roughly what the outcome is in most cases. My advice when diagnosing many problems is to repair at small steps and test after each move to build a better picture of what was actually wrong. Also great vid again I would like to have more info on SCR systems as info is limited out there and sometimes I find it hard to diagnose. Cheers Andy

I’ll say this again at the cost of repetition - What Dan does is not basic knowledge. This is really deep rooted knowledge of a lot of things. The Brittanica of car diagnostics. Fantastic Dan! I wish you were my teacher.

Wow. Watching your video and you telling about the details on how it works in detail is so interesting. Never thought that there were so much research, innovation and controls implemented. Even simple things like the exhaust is high tech rocket science. 🤓 I love the final comment regarding the probable cause why it failed in the first place. Leaking hose. 👍 Must maintain all parts to avoid expensive parts failing.

That Saab APC gauge is very cool. Love these old special tools

Hi Dan, Again, another great video! Indeed you are right; fault codes on a DPF Filter are though ones. Most of the time the faulty DPF Filter is not the cause of the problem, but the victim. What I always check before in the live data when it was the last time that the car started the regeneration at his own. Then you know that at that time everything was working fine without any faultcodes presented. I also always check other faultcodes and checking the glow plugs. No working glow plugs, no regeneration what leads to a clogged DPF Filter, and/or a damaged and leaking turbo. When a turbo is leaking exhaust gasses at his waste-gate-axle, is always a ‘smoking gun’ to me. The separated pressure gages are a must to see if the pressure sensor is telling the truth. In my mind I also created two of the same gages to do the measurements. But unfortunately to much broken cars, so didn’t find the time to create them. Keep up the good work and looking forward to your next video. Kind regards, Geert

Hey Danny. Again a very interesting video. I am an automotive engineering student from Belgium and always learn a lot from your educational videos!

Fantastic info and diag on that DPF Dan! We don't see many diesel cars here in the USA so it's very educational to see how the pressure and temperature sensors detect DPF issues, and what good specs are. Saab gauge! 👍

I was trying to work out how the DPF could be affected by new carpets!

That is an extremely comfy place in the car to put dpf, so easy to service!

Hey dan, some thoughts on the failed part: Looks like the washcoat is very inconsistent. That would be the silvery stuff on the surface. You never, ever, want to see something like this on the DPF. It is also visible on the rear of the filter; there it isn't as visible, as there is no soot stuck to it. The first part of the filter is actually just a catalyst. You can clearly see that on the first part, all the cells are open, whereas in the second one, only every other one is. The reason is that for a DPF every channel is blocked at one side; the filtration is actualy happening in th walls between the cells. This is also the reason why DPFs have quite high back pressures. For this reason; a too heavily coated DPF will experience too high back pressure, especially when the part is new. The coating blocks too many of the pores inside the monolith. During the first regenerations, this coating is quickly deteriorating, which leads to reduced back pressure. Back pressure of a DPF is extremely sensitive to soot loading. Your pressure readings may actually be sort-of OK for a heavily loaded DPF. Ideally, you'd want to do a regeneration (if possible) before conducting backpressure testing. Many ECUs will adapt their backpressure model according to an aging factor; if the ECU is not told about a new filter, it may trigger a false diagnose. Also, high back pressure is usually cause by one of two things: Ash loading due to age (ash is a result of oil consumption, and cannot be burnt during DPF regeneration), or due to excessive smoke of the engine. A Dirty MAF can easily causen a overloaded DPF. Considering the almost 200.000 km on this vehicle, both are possible for the original filter (the one you never got to see). Since the front of the filter was quite clean, I think it is safe to assume that the replacement filter did not run for very long. Within 50 or so kilometers, you'd expect the front of the filter to be black, so excessive soot load was likely not the cause; and replacing the filter AGAIN was likely the correct call. If the filter was damaged (cracks, blown out plugs), the differential pressure would be too low, and this shouldn't trigger a limp-home mode. Limp home mode will also increase the back pressure, as it will be run without EGR, and you will have significantly increased air mass flow vs. normal operation. Can be up to 50% more, depending on operationg point. So again, for the backpressure test, the limp home mode should've been cleared. 200 hPa at no load 2500 RPM is still too much, though.

Wish more mechanics were like you. Most are simply guessing and throwing parts into the car when the problem is "problematic".

Dan.... you need to fly to USA and teach all mechanics about emissions systems because here nobody understand how they works... Thank you for another great video!!!! 🙏🙏🙏

awesome ! so many things I learn from you everytime I watch your videos thanx

13:23 a new one looks like enamel free ceramic, kind of light tan color. This is a piece of s#$t. It's amazing what they are trying to get away here. A frickin' expensive part too!

I love that SAAB pressure meter, take good care of it 💯

Just found this channel and I love the content very informational thank you

Hi Dan. Nice to have you back. I am no mechanic but enjoy watching every video of yours. Keep up the good work.

Was that first one a Dorman Product? 🤣🤣. Great job as always pal.

I tell all my junior techs ,the DPF is basically the thrash can catching all the impurities . The sub straight in the first filter clogged ? Incorrect cfm rating? Thats the last thing we replace on a vehicle but most shops that the first thing the want to replace Yes you are correct it's all about the temps Great video

The first " new" dpf was made with wrong specification or it's just cheap recon, cleaned with garden hose and simply blocked.

2 comments 1- we always check the egt sensors with a cold engine so you can compare them with other temp sensors like Inlet temp and coolant temp,they should always be in the same range give or take 4or 5 degrees off. 2- the weird markings inside the dpf I have seen before,when the dpf is fabricated there are stickers on the parts they put in there but they don't always take them of so they leave burn marks and not burned material in the dpf

You need to be an instructor. You make it very easy to understand on any of your videos. You talk on a tech level. Had lots of new parts defective in my time.

Forgot to say again love your diagnose. Appreciate you from Denver, CO.

🤣🤣🤣That blooper had me laughing but the info on the repair with the tools you showcased informative. When it come to auto repairs DiagnoseDan is the man!

Top work as always Dan, I should be replacing another DPF this coming Monday Toyota RAV4, apparently is regenerating from cold start straight away and the smoke it’s quite embarrassing... I’ll make sure I do my homework although I was only asked to replace it 🤷‍♂️😉👍👍👍👍 cheers

I'm sure aftermarket parts have been getting worse in recent years. Great work I really enjoyed this

My intercooler on my ford transit rotted away causing heavy sooting in my DPF filter and sent the engine into limp mode, after replacing the intercooler it took a fair few miles to get the van to re-gen and clean out the filter but all good now thankfully.

Another great video that has it all - diagnosis, repair, confirmation and most importantly, indication as to why the DPF got clogged in the first place! Shows you how ingoring small problems can lead to huge costs.

Your preaching to the choir here Dan. At all the years I have spent with the dealer. Have had many a disagreement with parts that were no good right out of the box. Keep up the good work. Ps. There are much better prices on the mk908p. Autel so coming out with a new top of the line king of the hill scan tool. Very soon. Be well.

Thanks Dan. I have been waiting for a new video for a long time. Great to see you back. I was wondering if you were still here as I got no reply to any of my last comments under your older videos. I started watching every one of your videos from the beginning and have watched some of them more than 3 times. I can't thank you enough for sharing your knowledge with us "the mechanics KEEN to learn" Thank you

Great video Dan. Can’t tell you how many VWs we see that need a dpf because owner ignored an issue that damaged the dpf.

That first filter must have been a BWD part, Broken When Delivered 😂

Thanks Dan! I like the fact that you put up some diesel content. Most automotive channels are US based, where everything runs on gasoline. Here in Belgium ofcourse about half of the cars are diesels, even down to the smallest opel corsa's, although this is slowly changing.

Diagnosedan I've been telling many people for quite some time now that new does not always equate to good or better. Always research the company and distributor of said parts. Thanx dan!

I am a beginner and I learn a lot of things here, thanks Mr Dan

We love DiagnoseDan ❤️. Love from Nigeria

Awesome diagnosis big thumbs up 👍

I have never seen a person who understands cars like you Sir!

Dan, Excellent as always. To bad you didn't bore scope the new DPF. I would suspect the the new unit had a different honeycomb structure making it more open. The one you removed looked chunky in it's design.

I dont change DPF, i remove clean it empty ash put it back, change engine oil to C3 5w30 dpf specific oil problem solved and also leave car running with AC on when i stop for 5 to 10 mins between places.passive regen no blockec DPF.🤣 never use additifs that enzyme speed regen it blocks it faster with soot n ashes.i also lock the car from outside with engine running to be safe.all 4 doors are mirror tint.car Alfa 159 2.4 jtdm

Would have been interesting to see the inside of the new one you installed, compared to the one you took out. Reminds me of the wheel speed sensor, other put in new, but new part was no good. Lesson being, the least expensive part is not always the best option!

Where’d you get those double hinged ratchet wrenches? Those look awesome!

What a nice morning...i was bored on my tradmil and boom....this guy made my day

Time spent watching your content is never a waste, great work and heaps of useful info. Thank you :)

Another great video Dan and some nice tools on show too

Dan, you should of visually inspected the second replacement dpf and compared it to the internals to the first (bad new one) it might give you some clues as to why the pressures were so high.

The cheap parts are expensive at the end, Grat video Danny!

That camera was pure VooDoo ! Always love your stuff Danno,,,

I like your staff. Old school gauge, new camera is really cool. I have 10 mm camera to see those too, maybe tommorrow wv polo catalyst. Runs ok, no codes, little rich, 205ppm is no no...

Good to see you back for the new year. Great job.

You're the best

I think my doctor has the same camera which i call the butt cam! Its "steerable" like yours! All kidding aside, being able to aim or steer the tip could be very useful for certain inspection situations. Great video as always!

Excellent Dan! Love the blooper😂😂

I wanted to see inside the new new part and the original for difference. That's the knowledge.

Hey DiagnoseDan I wanted to know if you could point me in the right direction on a 2011 BMW 750i xDrive I am having some issues with? Huge fan and also student of your work, keep making these amazing videos as it has helped in enhancing our company skill sets!!!!

Terrific video Dan! I like the comparisons! Congratulations to the winner, Mr. Pruitt!! 👏👍👍

Very good Dan.

💪👍 great video. At least the other shop made the right call but I feel like they were just guessing. After installing the new part they could have done those simple tests to diagnose the new part wasnt working.

Thank you Dan. Expensive parts can really freak you out. You'd get discouraged in the first place.

i like to get the dpf up to temp before checking pressure. also after a regen. sometines you can reset the ecm soot level and trick it into a regen if the system has a lockout. been a while since the last video was starting to get worried

Dan you’re the Man! Another great fix

Dan, were you tempted to put the camera up the new DPF and see what it looked like before installing? Or did you on the sly and not show us?

great work Dan. cheers NZ

Well Dan that device certainly looks very vulnerable to damage form flying stones bottoming out over speed humps etc.

Dan is back! If you want to do (more) good by the owner of that car replace his accessories belt too :))

Another great video Dan , that blooper was priceless ; )

Can you do a vid on fitting headlamp bulbs,seems they cant get them in properly,tired of being blinded by one lanp at night !

Nice job Dan.. Shame it didn’t get rid of that annoying low fuel light!

dude you are a magician

Nice work on both the video and diagnosis

Hi I have watched you some time you repaired a BMW X5 I think it had been crashed and repaired but had errors you used an amp reader that plugged into the fuse holder, what was the make ? Thanks keep up the good work

Wow wish I had entered earlier omg I really need that 😭 reader and diagnostics tool wow ;^)

Another great video and Dan fixed it again.

Diagnose Dan came thru again. Could grinding off those sensors could metal shavings have gotten inside of the filter. Looks like a pretty shabby grinding job. Just wondering Dan. Good diagnosis 👍👍👍

This is absolutely Awesome video by DiagnoseDan

We did do on Cummings engine in America Dan I never seen diesel Subaru Dan

Should have gone with A1Cardone parts. ...Roflmao, couldn’t keep a straight face.

Definitely agree. Get old DPF cleaned if possible. Been caught out with dodgey aftermarket DPF myself & the company seemed so plausible that supplied it!

Once again another great video from you Dan,.

thank you Dan

Fantastic, thanks for the clear explanation of how it works and how to diagnose. Do you normally have to remove the temperature sensors before sending it away for cleaning?

You should have cut open the original, butchered DPF to look at the blockage. Also looked in the replacement that worked to see the state of it. All good stuff though.

Hi dan, I worked as a builder in Germany close to the Dutch border and got to be friendly with a lot of Dutch guys who looked after us Irish very well and we went into holland every chance we got because of the help and of course the lovely Dutch beer the guys gave us, I will never forget the help we were given and seeing your channel just shows the Dutch help is still alive, I've been back to holland a few times and when this crisis is over I'm certainly going back again and if possible I'd love to drop in and buy you a beer or if you're driving a coffee but none of those funny cakes my mate used to buy and munch, love your channel dan and as a complete idiot when it comes to cars you make it so simple to diagnose

I would like to have seen that aftermarket dpf cut open to see what the fault was inside.

the metallic substance in the dpf looks like it may have come from the inferior catalytic converter built into the dpf which should be burning the post injected fuel and raising the temperature above 550c which would oxidise (burn) the soot in the dpf so I would say the dpf is blocked because the required temperature has not been achieved to regenerate the dpf a problem I have seen in many cheap dpfs bought on ebay

Since the first replacement DPF was bad and you even have the video showing this, did the Supplier honor the warranty on the part and refund the money? Did they inform you of what the problem was or even bother to test and inspect the bad part?

Great video. Very informative

The fault with this aftermarket DPF must be similar to the problems with aftermarket CAT's, the monolith inside is constricting the exhaust flow so much that it causes a code. Basically they're cheaper for a reason. Newer engine management systems have such small tolerances that aftermarket parts just aren't good enough.

Saab turbo APC♥️ got few of them but only one worth to keep, Saab 9-5 3.0t hits 300000kms last year ♥️👌

petrol,diesel and hybrid! i like this channel