Engine fumes coming into cabin

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Puck
1.6 8v
Posts: 12
Joined: Thu Jun 08, 2023 11:54 pm

Engine fumes coming into cabin

Post by Puck »

Hi people. I have a couple of questions, looking for help.
I needed a better car so, with fond memories of a 406 diesel estate in the past, I got another one. It's as lovely a motor as I remember but fumes have started coming into the car. I've searched this fantastic website and got some info. Yes, the front door seals are knackered but the rear door seals seems ok ... can that really be the problem ? Otherwise, maybe it's the injector seals leaking. However the areas around the injectors are squeaky clean with no " Black Death " evident.There is a bit of misting around the rocker cover breather so I followed it down expecting it to join the air intake somewhere, but it seems to go down to near the bell housing. Can someone explain where it's going to down there ?
I've tried driving with windows open and windows closed etc. but it's getting worse and worse. I've tried changing re-circulation but it doesn't seem to make much difference. Maybe that re-circulation flap is stuck open ? I'm told that I can see that flap if I remove the pollen filter but where do I find the damn pollen filter ? I'm in Portugal with no Haynes manual yet. The car is un-usable right now. Please help. :(
Puck
1.6 8v
Posts: 12
Joined: Thu Jun 08, 2023 11:54 pm

Re: Engine fumes coming into cabin

Post by Puck »

Hi, me again. I found the pollen filter ( good old YouTube ! ). Took it out. It revealed the flap controlled by re-circulation button. It was just dangling down vertically. With the engine running and heater control turned up to max the button made no difference. How is it opened and closed ? Anyway, I Gaffer taped it closed and re-fitted the pollen filter. I took the car to an exhaust centre. The guy put it on the lift and examined the underneath. He found a couple of pin-holes where the tailpipe joins the rearmost silencer and masticed them for me but said that's not the problem. He showed me where the manifolds and turbo are behind the engine. He pointed out some oil leaking onto an intake pipe which he reckoned was then dripping onto the exhaust, most likely the cause of the fumes. Could that be leaking from the rocker cover gasket ??
Feeling much better about the car now, though my sisters still refuse to get in it until I've fixed it properly !
So my questions are these:
How is that re-circulating flap actually controlled ?
And where does the largish bore rocker cover breather go to ?
Mounted on the bulkhead , directly behind the inlet manifold, there's a box of tricks with wires going to it and a couple of vacuum pipes coming from the brake-servo. What's that all about ? There's a blue electric plug and a grey one connected to it.There's also a yellow two pin plug just dangling in the wind from the same harness. Should that be connected to something ?
Cheers, guys = looking forward to some answers. Thanks in advance.
GingerMagic
3.0 24v
Posts: 3570
Joined: Fri Apr 06, 2012 9:02 pm
Location: Bournemouth

Re: Engine fumes coming into cabin

Post by GingerMagic »

Hi 😊

After reading your first post I would have mentioned the Flexi section of the exhaust, it's designed to flex as it's name would suggest, but if the engine mounts are worn then it's forced to flex more than it should and then splits - however I'm sure the exhaust guy would have spotted it.

The recirculation flap is controlled by a little motor that sits behind the glove box under the dash, but the cog loses its teeth over time and therefore doesn't open and close the flap like it should. This can be replaced but it's difficult to get to, and they are not especially built to last.
On my old car I just smashed the flap so it stayed open, I'm a fresh air type of guy.

The 1, 2 or 3 things on the bulkhead ( solenoids, 1 on an Hdi90, 2 on the Hdi110 and 3 on the 2.2Hdi - depending on year ) are vacuum controlled - these are basically vacuum controlled switches that operate the turbo wastegate ( grey plug ) the EGR valve ( blue plug I think ) and the Air doser ( black plug)

As for the oil leak, I can't say for sure - not my area of expertise I'm afraid.

The door seal can be pulled off and rotated so the damaged section at the bottom is now by the latch, this'll stop water and smells coming in.

How is the handbrake? It's a 406 weakness.

I've owned many 406s and I still think it's a great all-rounder and hugely underestimated, until you own one and then realise how good it can be 8)
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
Puck
1.6 8v
Posts: 12
Joined: Thu Jun 08, 2023 11:54 pm

Re: Engine fumes coming into cabin

Post by Puck »

Hi, GingerMagic. Thanks for speedy response.
The recirculation flap was just flopping backwards and forwards- didn't seem like it was connected to any control mechanism or anything.
Thanks for info on vacuum switches, it explains a lot.
The door seals that are knackered are the lower ones, the ones that get kicked every time you get in or out. They've become disconnected from sill. The previous owner ( for 15 years ! ) had attempted to glue them but I've gaffer taped them too. Good idea about reversing them. The other end of them are sealing the rear passenger doors, one straight line, easy to turn round and swap with other side I suppose.
The air con isn't working. Previous owner said there was a gas leak in the aircon radiator. Can you tell me where I can find that?
The car is 2.0 HDI 110, year 2000 and it's done 354,000 kms - about 210,000 miles. Underneath the chassis etc. was just amazing, being used to UK cars. No rust around here, no salt on the roads in winter, and Portugal is dry, dry , dry. Second hand cars are really expensive here, I paid 2000 euros, which is pretty good here. I've seen other 406 estates for sale with 450 to 500,000 kms ! They look after them, do the proper servicing etc.and they don't rot away.
Thanks for help, I'll post progress.
GingerMagic
3.0 24v
Posts: 3570
Joined: Fri Apr 06, 2012 9:02 pm
Location: Bournemouth

Re: Engine fumes coming into cabin

Post by GingerMagic »

Ah, you mean the sill strips that get kicked off when you get out of the car - last time I looked these were still available new from Peugeot, I'll investigate more later in the day.

Sorry, there should be a little rod attached to the recirculation flap, probably long gone by now.

Rust isn't a massive issue on the 406, rear cross member on occasions ,the weak spots are Handbrake, Drop Links and Strut Top Bearings other than usual wear and tear - it's mostly electrical gremlins that build up over time that makes owners lose faith.

Feel free to start a project thread, you can add pictures using a 3rd party hosting site of which there are many available

I'm only replying now at 2am cos the wife's snoring is keeping me awake.
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
Puck
1.6 8v
Posts: 12
Joined: Thu Jun 08, 2023 11:54 pm

Re: Engine fumes coming into cabin

Post by Puck »

Hi. Made me laugh first time looking on here last week.
My handbrake not good, and the engine cover was in the boot cos mountings broken — common problem! Handbrake just a matter of maintenance etc. My last car here Seat Ibiza 1996 with VW 1.9 diesel engine.. It’s done 540,000 kms about 340,000 miles.
Great to be back with 406 estate. It was the best car we’d had, unfortunately I had a small accident, just enough damage to write it off. Before that we had 205 diesel, 405 estate both impressive motors. Then I got a 307 estate, the worst and most troublesome car I’ve ever owned. 🤪🤪
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GingerMagic
3.0 24v
Posts: 3570
Joined: Fri Apr 06, 2012 9:02 pm
Location: Bournemouth

Re: Engine fumes coming into cabin

Post by GingerMagic »

Yeah, the 307 is a bit hit or miss for trouble, and the honest the VAG 1.9 diesel is a corker even if the cars are super dull

Plenty of information on here about the potential issues, I'm sure you've had a peek already but before you approach any kind of job then have a look first so you know what to expect :cheesy:
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
Puck
1.6 8v
Posts: 12
Joined: Thu Jun 08, 2023 11:54 pm

Re: Engine fumes coming into cabin

Post by Puck »

PROBLEM SOLVED !!!!
Haynes manual finally arrived from England. Read about air distribution. Turns out there are two rubber flappy type valves behind the plastic stuff in the boot to let air pressure out, for examplewhen you close the doors. These were both only half fitted, allowing outside air into the car. Fitted them properly, problem solved. Hooray ! Now, does anyone know how to change language on the dash? I’m learning Portuguese but English would be easier.
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