Dipstick tube came off A4 B6 & NCT emissions failure

MrCostington · 15-01-2021 10:02pm #1

Hi, I had my NCT on my A4 1.6 petrol (B6, '02) on Tuesday. It failed the emissions, man said they did not even test it as too much smoke. When I got in the car the CEL light was on and it was running really rough. I limped home and did a scan, P0301, misfire.

Car not starting well and huge flatspot below 3,000 RPM.

Winding back to Tues morning before the test, I was getting it ready, checking fluids, lights etc. Engine oil seemed way low, dipstick was dry! I did notice that the dipstick tube (not sure if that's the correct name, the bit you stick the dipstick into) was loose. Anyway, I put about 700ml oil in an it was near the top mark.

So did the NCT with the results above. Retest on Sunday.

So this evening after work I noticed lots of smoke coming from the exaust, think it might be burning oil. I went to check the oil again and the tube came undone completely and fell down in the engine bay.

So I'm now theorising that in fact, due to the loose tube, I got an incorrect reading and overfilled with oil. Any thoughts?

As regards the tube, what would the procedure for refiting? Can only find info in the 1.8T which looks very different to my 1.6.

Thanks!

Toyotafanboi · 15-01-2021 10:56pm

Honestly, it doesn't sound too promising, one way or the other.

Those dipsticks are prone to perishing and breaking off.

What mileage is on the car? When did it last have an oil change in time or mileage?

They are fond of a sup of oil but it shouldn't cause an NCT fail unless it's chronic. I think you may be dealing with seperate issues though regarding the misfire.

You should replace the dipstick and investigate the oil issue before looking at the misfire as that is likely an easier, cheaper fix. There's a slim chance it's related but fairly unlikely.

Doublebusy · 15-01-2021 10:59pm

No harm in doing an oil change with the correct amount of oil while your at it

MrCostington · 15-01-2021 11:17pm

@Toyota - Last oil change was about 15 months ago (I know ...) and say 3k miles. I'm thinking that on Tues morning the tube pulled up so when I put the stick in again it was not going all the way and hence I overfilled thinking it needed it. It's never been smoking before. EDIt miles about 100k (miles)

If there was 500 to 700 ml too much oil might that cause the smoke, perhaps through a breather, and/or could it have fouled a plug causing the misfire. I'll pull the plugs tomorrow.

Do I attack fixing the tube from above or below?

@Double - Yes, it is overdue a change but I'll wait till it passes the NCT.

Toyotafanboi · 15-01-2021 11:33pm

https://www.youtube.com/watch?v=3Pt5VqYzodM

Should be very similar to your car.

Get a new dipstick and see what the oil level is like. I dont think your oil service interval is too bad.

If the oil level is ok, then you're looking at either fixing the misfire, a fueling issue or an oil burning issue, or a combination of the three.

If the oil level is overful, drain it out and then see where you stand. I dont think a 700ml overfill (which is a total worst case and assuming the car has burnt no oil over the last year which is very unlikely) should have done any serious damage, but you need to confirm whether it is or isn't before moving on really.

MrCostington · 16-01-2021 12:02am

Hey, thanks for the vid! Not sure if I'll be able to get one tomorrow, will call the dealer in the morning. I'll dig it out and see if I can just re fit it for now. If overfilled, I think I can suck the excess out. I made a thing with a outer sheath of electrical cable attached to the plunger of a soap dispenser to remove AFT from my other car a while back, fed the plastic tube into the tube, worked really well (you need to get the box up to temp to check level, fine tuning required).

I have checked the oil in the last year

I did have to top up since then.

Re fueling issue, I thought of that as regards to the flat spot. If the pump was bad, or filter blocked etc, would the fact it clears over 3,000 RPM not exclude that, i.e. higher demands on the fuel system at high revs?

Toyotafanboi · 16-01-2021 12:11am

Usually it snaps where it enters rhe block, i wouldn't say there'll be any fixing it but have a go. They break a fair bit, dealers will have them in stock, they aren't expensive.

I was thinking more along the lines it was getting too much fuel, not too little and maybe that's why it's smoking but that's just a guess at this stage really.

10fathoms · 16-01-2021 12:20am

Any chance it's a faulty coilpack causing the misfire?

MrCostington · 16-01-2021 12:42am

Toyotafanboi wrote: »

I was thinking more along the lines it was getting too much fuel

Ah, that never occurred to me. What might cause that?

I'll fish out the tube and try to get one if it's broke.

MrCostington · 16-01-2021 12:43am

Re the coilpack, it could be, but it was replaced about 3/4 years ago

greasepalm · 16-01-2021 12:50am

Good old german cars and their coils failing,if you can remove plugs look for oiling up to see how bad.

If dipstick tube is ok align it on the base and guide and a tap with a bit of wood can slot it back into place,if brittle needs a new one.Tube is done from above.

MrCostington · 16-01-2021 1:50pm

Update - got the tube out, it's in about 5 pieces. Not 100% sure I did not let any bits drop into the engine, from the ring of plastic that was inside the metal tube. I'll suck out some oil later and then take a chance, car is worth 200 quid if that.

The dealer has them for a tenner, but say I cannot collect due to covid so must send it by van and can't till Monday. Summerhill Spares don't have one. I just rang the dealer again to beg to be allowed to collect, but parts dept are closed!

I'll have to cancel my NCT re-test, but the call center is closed now. Is there a direct number for Northpoint, I cannot find one.

I seem to have lost my socket for the plugs so will get one after lunch.

greasepalm · 16-01-2021 2:04pm

Old engine oil needs to be hot before attempting extraction as its thicker than atf.Dont get second hand as brittle.That engine looks like same one in Vw Bora which burnt oil and does in cats.Thinking single coil pack in under manifold and where plug leads changed at same time as one might be faulty.

MrCostington · 16-01-2021 2:30pm

I think I'll give sucking the oil cold, agree with what you say of course, but don't want to start it. Hope to be lucky and pick up any bits of plastic while they are near the surface, hopefully.

Well, yes I'll get new. Just tried Summerhill to get going to the NCT tomorrow. And yes, my colils are buried deep in the engine, one unit feeding the 4 plugs unlike the newer coil on plug setup. I think the garage changed the coil and plugs when it was done a while back.

Hope my cat is ok.

Toyotafanboi · 16-01-2021 2:41pm

I'd probably slow down the pace, let the retest go if it's too short notice. Don't go sucking out oil when you aren't even too sure if it's overfull or not.

Get the new dipstick, fit that, get an accurate reading and move from there when you have at least one accurate piece of info to start with.

MrCostington · 16-01-2021 4:59pm

Toyotafanboi wrote: »

I'd probably slow down the pace, let the retest go if it's too short notice. Don't go sucking out oil when you aren't even too sure if it's overfull or not.

Get the new dipstick, fit that, get an accurate reading and move from there when you have at least one accurate piece of info to start with.

Yes I wont try for the test tomorrow, in any case I doubt it would be wise to drive without a dipstick, and I'm sure they would refuse to test it.

About sucking the oil, I meant just a little off the surface as I may have dropped some plastic bits from the tube, see my post 12.

I pulled the plug that had the misfire, in a very sorry state (it's about 3,000 miles old) - what are those deposits on it?

greasepalm · 16-01-2021 6:33pm

Trying to burn off the excessive oil usage,what make of plug ngk or other?

MrCostington · 16-01-2021 9:38pm

Ah OK I see. Hope it is just overfill and nothing more serious.

Plugs are Bosch Super 4 R6

greasepalm · 16-01-2021 11:51pm

Its engine wear due to lack of oil and rings glazed over.Get a ngk plug far superior than bosch and it should run better for a while.

MrCostington · 18-01-2021 9:06am

Hi, I had already bought 4 plugs before you posted that, happened to be Bosch again. Put them in yesterday and will order the tube when the dealer opens this morning.

MrCostington · 21-01-2021 3:00pm

Finally got the tube fitted yesterday, oil level was OK so not that.

Engine still running badly, it feels very flat below 3,000 RPM, above that it's fine. Took it out for a 30 min spin on motorway this morning, no change. No CEL and no codes on my very cheap scan tool.

greasepalm · 21-01-2021 5:19pm

Did you change that plug and also while running pull off the plug leads AND BEWARE OF HIGH VOLTAGE as the one that does not make a difference could be gone.If its smokey engine might be gone.

MrCostington · 23-01-2021 8:20pm

An update. I no longer had the misfire since I changed the plugs, so no need to try the above, I think? BTW, would pulling the ingector cable not do the same, without risking a shock (I got a bad one once years ago, my hair is still standing!!!).

Anyway, it passed today! And by a comfortable margin.

I did find a vacuum line connected just passed the MAF sensor and it looked like the short connecting tube may leak as it was loose so I replaced that. Not sure if it made any difference.

Still have major flat spots below 3k (cold and hot) and very hard to start from cold.

Dipstick tube came off A4 B6 & NCT emissions failure

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