1986 R107 SL - Smelly or is it just me?

1986 R107 SL - Smelly or is it just me?

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Discussion

petjam

Original Poster:

489 posts

146 months

Monday 10th July 2017
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Morning all,

I have recently made my first foray into classic car ownership with a 1986 300SL. It’s in great condition, no rust and has just been issued with a clean bill of health down at Colin Ferns.

One lingering potential issue is the smell of fumes / petrol from behind. In my son’s words “This car would be great in a race as it would gas everyone behind”. Is this an issue? Or it is just what old cars smell like? I have never owned an older car so have no frame of reference.

It was down at Colin Ferns with an effective blank cheque for repairs so if it needed anything done I am sure he would have mentioned it.

Is it just me?

Mr Tidy

22,313 posts

127 months

Tuesday 11th July 2017
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petjam said:
Morning all,

I have recently made my first foray into classic car ownership with a 1986 300SL. It’s in great condition, no rust and has just been issued with a clean bill of health down at Colin Ferns.

One lingering potential issue is the smell of fumes / petrol from behind. In my son’s words “This car would be great in a race as it would gas everyone behind”. Is this an issue? Or it is just what old cars smell like? I have never owned an older car so have no frame of reference.

It was down at Colin Ferns with an effective blank cheque for repairs so if it needed anything done I am sure he would have mentioned it.

Is it just me?
Probably not OP! Should have bought a proper car in the first place!

petjam

Original Poster:

489 posts

146 months

Tuesday 11th July 2017
quotequote all
Cheers! Don't blame me it was the wife who wanted it!

I read other threads on here about old cars having a certain "smell", I am wondering if that is what I am smelling and I am not used to it.

Paracetamol

4,225 posts

244 months

Tuesday 11th July 2017
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It sounds like it may be running too richly. Perhaps get the emissions checked to see they are in line with Mercedes standards.

It won't have a cat at this age but has a relatively modern fuel injection system..so shouldn't be too smelly

PositronicRay

27,012 posts

183 months

Tuesday 11th July 2017
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If it's just a whiff from a cold start, then okay when warm, it's probably okay. Early injection systems are fairly rudimentary. If it's all the time get it checked. Is the boot particularly smelly?

Old cars do have different smells, quite endearing. Strong petrol smells shouldn't be one of them!

Yertis

18,051 posts

266 months

Tuesday 11th July 2017
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An SL owner should answer this really. But old cars do smell more. The TR5 and 6 have a reputation for smelling of fuel, largely caused by all the high pressure fuel lines snaking around behind the cabin being made from a material that allows fumes to permeate. They can be replaced nowadays with lines made from teflon or something which stops the smells. The SL might have similar issues?

Riley Blue

20,955 posts

226 months

Tuesday 11th July 2017
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My Riley has its own 'fragrance' but exhaust or petrol fumes are a no-no as far as I'm concerned. If they're seeping into the car, they need to be investigated and dealt with, pronto.

Xtriple129

1,150 posts

157 months

Tuesday 11th July 2017
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Has it got the wind blocker? I have noticed before on elderly cars without cats that you get a certain amount of fumes that the dodgy aerodynamics sort of suck into the cabin when the roof is down. The wind blocker is very effective.

However, a Mercedes SL shouldn't really pong like that - has it got a different exhaust tailpipe arrangement? If all is standard then I would definitely get the emissions checked, they are easy to adjust on the old Bosch system so not a major worry unless something is buggered!

Lovely car OP smile

TR4man

5,227 posts

174 months

Tuesday 11th July 2017
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Have you queried this with Colin Ferns (I assume he is a specialist)? Did he take it for a test drive when he checked it over?


petjam

Original Poster:

489 posts

146 months

Tuesday 11th July 2017
quotequote all
Thanks all. I had him put a new MOT on it and it passed the emissions no problems.

Unfortunately it doesn't have the deflector. I think I will send it back, only problem is that it is not local and it will cost £300 return on a trailer!

Edited by petjam on Tuesday 11th July 12:36

singlecoil

33,601 posts

246 months

Tuesday 11th July 2017
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My (petrol) car is 15 years old and smells of petrol fumes, especially when starting. The smell comes from the exhaust, I am unaware of it unless I am starting off and have the window open. Anybody in the vicinity will be aware of it though.

It passes the MOT easily and has had the smell problem investigated at a reputable garage. Their analysis was that it's old and worn, and the only cure is a rebuilt engine.

tonys

1,080 posts

223 months

Tuesday 11th July 2017
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It shouldn't smell. Do you mean whilst it's being driven (roof up or down?) or when stood behind it?

Has it been unused for a while, if so it might just need a run.

If it smells of fuel something's not right. It could be split fuel pipe, blocked breather (can't recall if the R107 has a vented fuel filler cap).

Has somebody by any chance been undersealing it, if so it could be burning off the exhaust.

tapkaJohnD

1,941 posts

204 months

Tuesday 11th July 2017
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Quote, "the smell of fumes / petrol from behind"

Do you mean from the seat of a car driving behind you, or when you open the boot and are hit by the smell?

Modern fuels can diffuse through ordinary rubber hoses, even those rated for fuel, and 'perfume' the area, especially the boot if they run through there.
You should ask your restorer if they fitted hose to SAE J30 specification, in particular "R9/R11" hose.

You can order a copy of this SAE Standard at http://standards.sae.org/j30_199806/ but it'll cost you $76!
There is an online copy at: https://archive.org/stream/gov.law.sae.j30.1998/sa... but it messes up the tables so they are unreadable.

An alternative is S/steel armoured PTFE hose, but these need special connection fittings, or Hardline aluminium piping, both of which are also impervious, but obviously look very different.

John





petjam

Original Poster:

489 posts

146 months

Tuesday 11th July 2017
quotequote all
It has been driven quite a bit but the smell persists.

There is no real smell in the car when sitting in it apart from maybe a slight smell if the wind blows back into the cabin. The main smell is from behind. By that I mean when I was following my wife (in the SL) and I was in another car the smell was quite strong.

I think I am going to book it into this place: -

http://www.schmittmercedes.co.uk/

They were recommended by the SL shop who themselves have a 3 month waiting list to just have a look at anything!

petjam

Original Poster:

489 posts

146 months

Tuesday 11th July 2017
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It gets trailered to the above on Monday. 3rd time lucky, let’s see what they think.

Rower

1,378 posts

266 months

Tuesday 11th July 2017
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With the majority of cars on the road now having cats we do forget what the emissions smell like without them . I can always smell the unburnt petrol fumes from a car built before 1991 .

You Merc man is pretty well known and I would be surprised if there was a problem , but better safe than sorry i guess.

Jimmy Recard

17,540 posts

179 months

Tuesday 11th July 2017
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Mr Tidy said:
Probably not OP! Should have bought a proper car in the first place!
What would be a proper car rather than an SL!?

Your standards are high

idiotgap

2,112 posts

133 months

Tuesday 11th July 2017
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Our 107 has smelled a bit fuelly from time to time over the 10 or years we've had it.

When we first got it it was really strong, turned out to be some sort of secondary breather tank or something above the fuel tank which had a a hole in because someone had screwed something to the rear wall of the boot. I'm not a mechanic, can you tell?

Once I drove it without the petrol cap properly seated.

Last week there was a problem with a fuel line which meant there was fuel dripping onto the floor in the garage which we had to get sorted out.

Being a proper car, at the best of times, it does have a more powerful and evocative signature pong than a modern conveyance.

tortop45

434 posts

160 months

Tuesday 11th July 2017
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Why not go and look at some other SL,s and see if they smell as bad??????

CarsOrBikes

1,135 posts

184 months

Tuesday 11th July 2017
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The 'certain smell' of an old car is usually the nice interior not carbon monoxide haha, your SL is possibly very rich, some cars are adjusted this way to get running smoothly in my opinion, setting it right could expose other requirements. For instance it could have an air leak that wasn't diagnosed or someone didn't want to deal with, so it could have been compensated for.

After years now of driving catted cars these fumes become more obvious, but more intolerable which is a good thing, so have it investigated or as above, go try another.