300Tdi MOT Emissions Fail. How common is it?

My 1997 300Tdi failed it's MOT emissions test for the first time in the 12 years i've owned it. I take a look at how many 300Tdi Defenders failed their MOT emissions in 2021 and some of the things I did to help eventually pass the test.
See your UK Defender's MOT pass rate compared to other Defenders the same age: defender.lrworkshop.com/
MOT testing manual on emissions 8.2.2.2: www.gov.uk/guidance/mot-inspe...
LR Workshop: www.lrworkshop.com/
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[@BritannicaRestorations]

Come to Quebec! We have no MoT!😃

[@harveysmith100]

Afternoon Mike. So on your days off you watch videos about Defenders?

[@R.Sole88109]

Mike, You bloody tease.😆👍🏻

[@gibsonethirty2836]

Or Western Australia, same deal, no mot.

[@harveysmith100]

@@gibsonethirty2836 Yes, thank you, you two. I have another 9 to get through before I get classic car status. 9 more years of worry

[@thomasgibbs4655]

Or come to Birmingham and get one all you need to do is pamp your horn and it’s passed!

[@Rosbif06600]

My '96 300tdi has been "on the limit" for the past 3 years here in France which seems to have similar limits. This year I used some of that injector cleaner in the fuel and I "turned down" the deisel pump. I turned the pump screw 1/2 turn because a few years back, a new bigger intercooler was fitted and the garage boosted the pump to get more power. The MoT tester said it was well within the limits. I also changed oil and the deisel filter so what actually made the difference, I don't know.

[@johnchetwynd3618]

I always give mine an Italian decoke on the way to the MOT. It has never failed on emissions (plenty of other things though 😂). My MOT man jokes, that so long as he can make out the clock on the other side of the workshop, during the smoke test, it’s a pass 😂

[@gjackson123456]

As LR geek I always submit oil samples to a lab after each change and they can recommend change intervals based on the remaining additives in the oil and also see issues with the internals based on the various metal content. Really great service and an exceptional money saver as I'm up to 8000 mile intervals on my 300tdis and 12,000 mile intervals on my LR3!

[@davidyeates5525]

Sad to say I'm one of the 2021 fails 😪 (1996 300tdi) But only due to a bent conrod. The piston is only a few mm short but it's enough to reduce compression in no4 cylinder and create a bit of smoke. I've taken out the engine for a rebuild. Here's to a 2023 pass!

[@oldsteamer1747]

there is a adjustment lockscrew on the back of the pump 300 tdi ,so it can be adjusted for emmisions ,same as the old di transit ,and pug 1,9 pre hdi ,just adjust it down , old style engines will always pass as they were built to be worked on ,

[@tommepham2267]

Will, it depends a lot on how the test is conducted. I recently had problems with two Landrovers failing the emissions test. I found the tester was opening the throttle fully but releasing the pedal before the turbo had fully wound up. In one way he was being kind on the engine by not screaming it but this actually made it smoke more. I achieved a pass by offering to rev the engine while he observed at the rear. I was half a second longer getting to full throttle, so just a bit more progressive with the pedal and I held it at full throttle on the governor momentarily. Revving it a lot harder than he had done but the exhaust was a lot cleaner.

[@harveysmith100]

Very good info. My MOT man is very fair, tough but fair in sharing his knowledge. He has said the same thing, give your diesel a dam good thrashing on the was to the test centre. Cleaning out the intercooler and associated pipe is also good advice. I can't believe how much oil actually finds it's way into the intake but there we go.

[@gshort4707]

Oil in the intake can come from leaky turbo oil seals, but I suspect mostly it is from the breather. I clean my breather and pipe every couple of years (8,000 miles).

[@harveysmith100]

@@gshort4707 Yes, I did think about the turbo oil seals. I do the same, I clean it all out, normally just before the MOT. It's not cheating, honest!

[@Rob-cz7lg]

Just peel the sticker off, then they use the 3.0 figure

[@angusabbott5615]

I just drive to the garage in lower gear 3rd usually rather than having to thrashing along at 70 , I check the end of the exhaust is too hot to touch at some point on the way and never had a problem

[@gshort4707]

I have a 300tdi fitted to my 1972 Series 3. For many years I ran it without the Turbo. For some reason the MoT station did an opacity test some years, but not others. though I'm not sure it the opacity test applies to a 1972 vehicle. But anyhow, the first acceleration figure was usually about 2 or 2.5, requiring a 6 accleration average. It passed these with a figure below 1[m-1]. A couple of years ago I had the turbo and intercooler fitted. They have done one opacity test since then (in 2020) and it passed the "fast pass" test with a figure of 1.09. Thought the emissions sheet says "Turbo fitted: NO"!

[@TheSussexpillbox]

I just submitted my Ex British Army Land Rover Wolf HS 90 FFR for a TUV in Germany, when the vehicle had been in storage since 2016. I got it nice and hot, or as best I could and it sailed through. It does have an EGR system on the military ones. But I was expecting a fail.

[@AnthonyTeasdale]

I believe my engine is a 1998 300tdi Smoke K (1/m) 0.2 on the last MOT The car itself is a 1985 Land Rover 90

[@hammyh1165]

I used to take the fuel filter off and fill it with Forte deisel treatment, I've also used paraffin with good results. If your engine is ok it should be pass without any of this . My one has it's MOT this week it's more likely to fail on rust rather than emissions though.

[@petermenzies1714]

My 1997 300Tdi 110 Station Wagon failed the emissions test first time result was about 3x over the limit. My breather needed cleaning, my turbo was worn & oily and my fuel pump timing was erratic as a result of a worn (slotted inside) crankshaft pulley. After oil & filter change I replaced worn turbo cartridge, air filter, fitted new timing belt & pulley kit, checking timing, replaced hoses and cleaned out intercooler. passed smoke test result 1.3 after a decent drive to the MOT station. Interesting that you posted this as I was about to tune my fuel pump a bit to make the engine a bit more responsive without adding more smoke.

[@adolfadolfovich7297]

Good luck 😃

[@GeorgeFryd]

I watched mine pass on the smoke test machine, slight looks of disbelief, though the screwdriver I took to the front end of the chassis when replacing the front axle with a sal left much to be desired, oh well engine out now, crankshaft gear nearly off, still in tolerance before first rebore -- 90.44 - 90.55 clock says 156,000 miles

[@blackhat400]

Rebore" mines is on 405,000 miles,, runs great, never had the head off,

[@GeorgeFryd]

you'll probably end up spinning a main? you'll duff the crank, rods and probably the block, crank was definitely on the tilt and main bearings definitely wanted changing as well as head, cam shaft, camshaft bearing, timing housing rear (reading 150km, engine had been done before) you'll probably end up damaging cams and they are not cheap @@blackhat400

[@gjackson123456]

In Colorado we are allowed up to 40% opacity, so a 300tdi has to be really turned up to fail! Interestingly the 1HZ (NA) in my Troopy passes with better numbers than my 2 300tdis

[@stevedangerous1]

I was asked, what have you done to this Td5? What's the problem? Ive deleted the erg system, put a full sized intercooler on it, and it has no cat...and opened the turbo up abit... Hmmm emissions are better than when it was new! Go figure..

[@Defender110SLO]

With my TD5 for 13 years no problems I have almost half a milion kilometers and no EGR and catlisator. Cheers. 🍻

[@jackbacon3723]

how much difference does taking the cat off a 300tdi effect emissions?

[@fire44x]

Just about ready to mot 110 2.5 petrol been of road 5 year looking forward to a quiet drive

[@peterpeterson9903]

Biodiesel is my secret weapon for an MoT pass. Load of that in and it will pass cold.

[@RustyRecovery]

can i ask, is there a probe that checks the emissions or is it literally the smoke from a diesel? if they see the egr delete is that an instant fail ? cheers.

[@allthingsmotorized1885]

probe on the tailpipe that measures smoke values

[@northfolk6991]

Actually, not common at all... For me that is ;) 300tdi in my series 2a 1968 Classic vehicle, no MoT requirement lol :)

[@SID10101]

Late comment, but if you deface the smoke limit sticker. The default valve applies. Best chance to pass

[@martinhelmes609]

In Germany its impossible to drive 300tdi‘s, because they don‘t meet the environmental regulations, you can‘t drive into the cities and the vehicle tax is very high…….

[@seekerbeta]

Sorry, lots of the Defender that are not MOT anymore are probably becuase they are hitting the age when North Americans can import them, including myself. i notice so many 96/97/98 defenders on the road here that are EU or ROW spec... probably why they are not testing anymore.

[@williamprobert5124]

Turn the pump down get a pass turn it back up Easy have a cup a tea get on with your life