Fumes in cabin advice/diagnosis needed please

[ukmastiff]

Right first main job I must tackle ! , after 3 years away from me no one has bothered to fix this what a disgrace [8|]

Years ago my car had various oil leaks and I was told the cabin fumes were most likely oil drips on the manifold or other hot part of the engine. Now I have the car back I'm not so sure. I really cant see any oil leaks if I'm honest and there is a receipt for someone having then oil leaks ' diagnosed and cured' so i 'may' be in luck there.

When you drive the car there is a terrible stink of 'fumes' in the car that I assumed was burning oil due to what I had seen and been told years ago. I drove the car 150 miles home with the window open wide of course and had no problems with headache feeling unwell etc but my clothes stank by the time I got home.

So is this likely to be an oil leak or are exhaust fumes a more likely culprit, would they make your clothes stink ?

If so , as Andy.W has mentioned is the hatch seal the likely culprit , I cant see how fumes would come back at you at 70 (ish) MPH ? , unless there is some sort of vortex effect. The exhaust sounds slightly fruity but I think its just the back box being sporty and i do mean only slightly , there's no blowing sound anywhere that I can detect. Any practical expreience/advice diagnosing this would help.

Cheers

Mas

 

[sulzeruk]

The hatch is coming away from the frame or the rubber seal is knackered and not sealing against the frame. There can also sometimes be a gap between the ends of the seal. I would have a look at the seal first, if it is showing signs of being compressed or distorted, change it.
The prime candidate for smoking on the 2.5 engine is the cork seal at the back of the cambox. Cheap to replace and 10 minutes to do.
Alasdair

 

[edh]

Exhaust fumes get sucked in through the rear hatch seal / lights etc.. particularly when the roof is open - it lowers pressure inside the car

Is it worse with the roof open?

The other route in is through the gear lever gaiter

 

[ukmastiff]

Thanks for the swift reply Alasdair , I 'think' that's one of the cambox one is one of the seals they replaced but I'll look at it, as for the hatch it is definately 'lose' from the glass as water can be seen sitting in between the glass and the hatch ansd its on my to do list. However its a tiny tiny crack type gap and a lot of fumes, do you know if fumes can still come in the boot at high speed ?

( sorry edh we posted same time) , I havn't tried opening the sunroof yet in case its knackered dont want to find more troubles yet [] , the gator looks sound though.

Regards Mas

 

[sulzeruk]

Have a look at the rubber seal mas, it should be an even round shape, if is look squashed, get a new one. That will certainly help. Resealing the frame will also benefit it greatly to. I had this on turbo I owned and both needed done. Another question is what back box have you got fitted and how far does it stick out past your bumper as that can make a difference.
Alasdair

 

[zcacogp]

Mas,

You've asked two questions; one about oil leaks and smells from that, and another one about how exhaust fumes get into the cabin.

Oil leaks and exhaust fumes smell quite different in my experience. One smells like hot oil (not that unpleasant) and one smells like exhaust fumes - which smell very nasty! If you can tell the difference then sniff carefully next time you drive the car and have a think. However, oil leaks need to be quite large before they get smelly, so one that is so small you can't even see it is unlikely to be making much stink. I'd therefore suspect it's exhaust-related.

The back of the car does indeed produce a vortex - quite a sizeable one. The whole of the sloping rear of the car has an area of lower pressure clinging to it above about 35mph, and exhaust fumes are drawn up into this area from the tailpipe. (The point of the spoiler is to ensure a controlled cut-off between smooth flow over the top of the car and the turbulent vortex behind it.) If there are bits of the back of the car that aren't well sealed then these fumes will come into the cabin - it's one of the reasons why boots and rear lights are sealed so well. I'd start looking at these, as has already been suggested.


Oli.

 

[ukmastiff]

mm maybe I need an expert sniffer ( oil v exhaust) ,
if any of you qualify please give me a shout !.

I have no idea re the smell being oil or exhaust , I know it leaves a stink on my clothes

I am leaning towards exhaust fumes now and TBH I hope it is. When I get home tonight I'll check the boot seal and if in any doubt re the condition order one.

Ta

 

[JamesBall]

Mas - if you decide you need a new hatch let me know as I know of one that can be had for peanuts (owner was planning on just scrapping it) that seemed to be in perfect nick.

 

[ukmastiff]

Cant believe youve gone over to the other side ! , is your 964 really more fun to be in than a 952 ??

I dont suppose its Zermatt is it (joke) []

Good to know re the hatch anyway .....

Ta

 

[JamesBall]

Alas it is black.

Re the 964 being more fun, to me it is, yes. The quirks of a 911 really do add "character" IMO but mainly it is the noise

But there are many things that the 944T did better that I am not blind to. There's no chance of taking 2 kids bikes, a picnic and a day's worth of clobber in the 964!

I'd say the 944 was the better car but the 964 is more fun.

 

[944 man]

Oil leaks which end up on anything hot enough will fill the under-bonnet area with smoke and a large enough percentage of that will end up in the cabin. The real way to establish what it is, is by seeing when it happens.

Whilst youre moving only, then its probably exhaust smoke, but when you come to a halt too indicates that there are engine bay fumes coming in. Im still getting alot of engine bay oil smoke, because there was too much to wash off when the front seal was repaired.


Simon

 

[utopia]

I had a lot of exhaust fumes coming into my car, only noticable when the roof or windows were open, I checked the seal and all seemed well, the glass has come away from the frame a little but has been resealed.
I was cleaning the car one day and leant on the rear spoiler and noticed there was a little play in it, I looked at the 2 pins that hang down from the hatch lid and adjusted the length of them to take up a little slack and the fume problem has almost gone, might be worth a look.

 

[ukmastiff]

I checked the hatch seal last night ( using a torch sadly) it is well rounded and not perished. The glass certainly needs resealing but the gap is tiny .
Theres defo a gap under the spoiler but can that gap really go through to the boot from there doesnt the spoiler just bt on to the boot ?
Sunroof sits terrible all round but i dont think sunroof will be the real culprit.
As for smoke under the bonnet thats a good point. I had none even after an M11 blat. Also I gave the front vents a good sniffing , blower on and off and no fumes there.

Im happy to buy a seal but mine seems sound so i reseated it and im going to start temporarily sealing everything up as part of a diagnostic hunt !

I'll report back

Mas

 

[JamesBall]

I know nothing about anything but could it be a gearbox oil leak causing a little bit of smoke that is somehow getting in to the car through the floor?

 

[edh]

run a hose over the rear of the car - particularly round the lights....and see where the water gets in

 

[Ex Skyline]

It is exhaust fumes Mas'. I had exactly the same problem a couple of months ago just prior to my visit to JMG. Jon did loads of work on my car, not least curing the bad smell of fumes in the cabin. He taced this to my rear light seals leaking of all things. He said it was quite common on 944's. Took out both rear light clusters, re-sealed them. Bingo! No more smell of fumes. []

 

[ukmastiff]

Ive heard that light cluster thing before but my fumes are so bad i discounted it . If you had bad fumes and that cured it ? Im adding a cluster reseal to my long friday list !

Cheers ill report back when ive had the chance to get stuck in.

Mas

 

[944 man]

If its an oil smokey smell then its nothing to do with the exhaust or seals, unless your car smokes like a destroyer making a turn!

 

[ukmastiff]

You cant see any smoke at alll either under the bonnet or in the cabin
However ive always thought its an oily smell but i may well be well wrong. That is the crux of the problem. When drivng along theres no obviou smoking going on as far as i know either.

Ta

Mas

 

[zcacogp]

Have to say Mas, the more I think about this the more I think it is exhaust gasses coming in through the rear of the car by whatever means.

If re-sealing your rear lights is on the agenda for Friday then hopefully that will solve it. Alternatively, you could try putting some tape all the way 'round them on the outside to see if that makes any difference; it's not a permanent fix but would help diagnose it.

Best of luck solving it. Smelly cars aren't nice.


Oli.