burning smell- not the heating

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ninjasmith
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burning smell- not the heating

Post by ninjasmith » Mon Dec 14, 2009 2:00 pm

Hi there,

I previuosly oposted here about a burning smell we are experiencing in our newly purchased V6 petrol bongo. I thought it was related to the heating but after following all the instructions to chekc the fan I have decided this is not the problem (all seems to be working well). also I have now noticed the burning smellwithout the heating on.

the symptoms are that everything works fine but there is smell of burning generally I can smell it after 5 minutes or so and it seems to come and go. I've run the engine with the passenger seat up but I can't see anything or smell it coming from any particular place.

any ideas about what could be causing this? is this a big worry? maybe I should be taking the van to one of the bongo approved garages listed in the members section.....
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Re: burning smell- not the heating

Post by mikeonb4c » Mon Dec 14, 2009 2:36 pm

This has come up before (and recently). Have a search using relevant keywords. At least one owner I think said theirs did this, especially when engine hot in stationary traffic and smell drifted up via the engine covers (are they sealing properly - you can bend the latches a bit to make them fasten tighter if so). Provided it is 'normal' I wonder if va scavenger over-ride switch might be worth considering (I have one - v. handy)
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Re: burning smell- not the heating

Post by ninjasmith » Mon Dec 14, 2009 2:49 pm

hi I did do a search on burning and there was a thread about someone who was looking for a garage to take one for a burning smell and lots about the heating. there was one about seals as well. maybe I should have posted on the bottom of the relevant threads to find out if they fixed theirs.

what is a scavenger override switch?

thanks
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Re: burning smell- not the heating

Post by mikeonb4c » Mon Dec 14, 2009 3:14 pm

ninjasmith wrote:hi I did do a search on burning and there was a thread about someone who was looking for a garage to take one for a burning smell and lots about the heating. there was one about seals as well. maybe I should have posted on the bottom of the relevant threads to find out if they fixed theirs.

what is a scavenger override switch?

thanks
Good idea to post on those threads if they are not locked - the topic was discussed recently. I recall members like Apole (Andy) being active in the debate so could PM him.

The scavenger fan is an extra fan the Bongo has (like a radiator fan) just in front of the engine, and angled up at 45 degrees approx. It is activated if a sensor (near the handbrake I think) detects that temp. in the engine bay is rising above a certain limit, and it flushes fresh air through the engine bay to cool it. It also of course flushes out the hot air and smells that may be in it. It is when stationary that temp rise is likely to be greatest, as there is no forward movement to encourage air through the engine bay. And as hot air rises, and as the engine covers act like an upside down bowl and hold it, hot air and smells will seep through anywhere they can and into the cars interior.

I fitted an over-ride to my fan by taking a fused, switched 12v supply direct to it, bypassing the sensor circuit. This means I can put the fan on when I like, whether to help keep the car interior a bit cooler, or to flush any smell coming from my engine bay (I sometimes get a slight whiff of diesel when stationary). I did a quick report on the job some while back - have a search. Concern has been expressed that I could mess up the ECU doing stuff like this, but over 2yrs its not happened yet and I think - since I'm working on the power supply and not the switching side of the scavenger fan relay - it seems unlikely that it would cause a problem. 8)
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Re: burning smell- not the heating

Post by g8dhe » Mon Dec 14, 2009 3:25 pm

What sort of burning smell, is it hot Oil ? The V6's are known to suffer from any leaking oil dripping onto the hot exhaust at the rear of the engine.
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Re: burning smell- not the heating

Post by ninjasmith » Mon Dec 14, 2009 3:59 pm

opinion among me and me fellow passengers who have smelt it is split. I would have said more rubbery - but I could just have been thinking that when I thought it was the heating. I'm not sure I acutally know what burning oil smells like. one of my mates who has smelt it is convinced its oil leaking onto the manifold. he does however have no qualifications to offer this sort of opinion!!

I was hoping by opening up the seat and running the engine I would be able to see or smell this sort of thing (or at least localise the problem) but I could see nothing....
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Re: burning smell- not the heating

Post by g8dhe » Mon Dec 14, 2009 4:50 pm

It takes only a very small amount of oil to make a smell!
Several drops adequately heated will generate smoke!
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Re: burning smell- not the heating

Post by ninjasmith » Mon Dec 14, 2009 5:04 pm

are you suggesting I take some oil and heat it myself to compare the smell. not a bad idea.

if it only takes a small amount to generate a smell then presumably I only have a very small leak. as there is enough to smell but not be visible!!
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Re: burning smell- not the heating

Post by Scott » Mon Dec 14, 2009 5:05 pm

You haven't run over a plastic bag or the like have you?

I did, it stuck to the exhaust and stunk for weeks. Nasty!
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Re: burning smell- not the heating

Post by manners » Mon Dec 14, 2009 6:56 pm

I used to get an occasional burning rubber smell on my V6, usually on kickdown could be quite acrid at times, i know the belts are self adjusting but i put it down to them slipping a bit, since Ive had every belt replaced no more smells.
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Re: burning smell- not the heating

Post by apole » Mon Dec 14, 2009 10:08 pm

Hi there,

What is the smell, is it rubber, coolant or oil?

Under the bonnet on the top air scoop, check to see if there is a small metal lever. If so make sure it's set towards the front of the car. This means the heating system uses cold air from the front of the car, rather than warmish air from under the bonnet. The latter will pick up more engine smells.

On mine the smell was burning oil, from a weep from the dreaded camshaft oil seals. Had these replaced last week, a labour intensive job, the parts are fairly cheap. Only one had failed on mine but all 4 were replaced as they were all getting old and brittle.

Fairly hard to spot, but what happens is oil leaks from the camshaft seals, runs down the front of the engine (behind the cambelt covers) hits the sump rim and runs round to neatly drip on the exhaust. I found it very hard to spot. Look carefully under the car at the engine.

If you have this send me a PM and I can let you know the part numbers/suppliers and a place that knows how to do this.

Good luck.

Andy
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Re: burning smell- not the heating

Post by ninjasmith » Mon Dec 14, 2009 11:40 pm

apole wrote:Hi there,

What is the smell, is it rubber, coolant or oil?

Under the bonnet on the top air scoop, check to see if there is a small metal lever. If so make sure it's set towards the front of the car. This means the heating system uses cold air from the front of the car, rather than warmish air from under the bonnet. The latter will pick up more engine smells.

On mine the smell was burning oil, from a weep from the dreaded camshaft oil seals. Had these replaced last week, a labour intensive job, the parts are fairly cheap. Only one had failed on mine but all 4 were replaced as they were all getting old and brittle.

Fairly hard to spot, but what happens is oil leaks from the camshaft seals, runs down the front of the engine behind the cambelt covers) hits the sump rim and runs round to neatly drip on the exhaust. I found it very hard to spot. Look carefully under the car at the engine.

If you have this send me a PM and I can let you know the part numbers/suppliers and a place that knows how to do this.

Good luck.

Andy
what type of smell. well thats a hard question as I'm not sure I know what burning oil or what coolant smell like. I would have said it was slightly rubbery but my friend is 100% sure its oil so we'll go with that on principle. are there any diagrams/photos of the engine available on the forum so I can see where the seals and the sump rim are and where the exhaust leaves the engine? Van bits are not a stong point of mine (yet!!)

I'll check it all out at the weekend. thankx for the help.
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Re: burning smell- not the heating

Post by apole » Tue Dec 15, 2009 9:35 am

Hi there,

Firstly it is quite hard to spot as the oil, on mine at least, was very slow trickle from one of the seals on the drivers side. It trickled down the engine, to the sump rim, that rim is then angled towards the rear of the car and it drips onto the exhaust.

Look under both sides of the car just behind the drivers doors. On the drivers side you will see the exhaust run acrossways to join the other pipe, before it then travels down the nearside of the car to the rear. Where the sump corner is, is generally where it drips, you may see a darker colour on the exhaust. Use a clean tissue and rub that round the edge of the sump to see if it picks up oil.

If you look at the sump at the front (this is hard as there is the lower engine cover in the way, and also the plastic cambelt cover across the front of the engine, you may see the oil as well, here it generally shows more as it gets mixed with dust and dries off a bit.

Some pics.

Drivers side looking at back of engine:

Image

Passenger side looking at back of engine:

Image

Notice the oil staining on the exhaust.

This is the front of the engine from beneath, this is during the seal replacement and all the belts, pulleys, covers etc are removed. My one was leaking from the top left hand camshaft seal, you can see traces of the oil leaking downwards:

Image

Smaller pic of above, red line points to the seal that was leaking, green circle shows where the leak was hitting air and gunging up, this is right next to the cambelt tensioner, that was fine and can easily be tested, the tensioner is around £300, unlikely to fail mind, mine was fine.

Image

I have to say the difference now without that smell is amazing, you kind of get used to it in a way and not having it now is great. I did see smoke once a few mins after setting off, sitting at a red light, thought the car was on fire !! That was the thing that prompted me to get it sorted !!

If you need further help with this let me know. How old and what's the mileage on yours out of interest? Cost wise you are looking at around £75 for the bits (that includes a new cambelt and 4 oil seals) and about a days labour. The coolant has to come out too.
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Re: burning smell- not the heating

Post by ninjasmith » Tue Dec 15, 2009 11:05 am

hi there,

mine is a 97 and 86000 miles. the previous owner said he had the camblet replaced this year so I'm loathe to do that unles we have too. I guess maybe they have to take it off though to get at the seals? and then maybe they have to fit a new one?

thanks for the detailed pics I'll check it out at the weekend. I'm all up for this self diagnosis lark so I can go to a arage and tell them what I need doing rather than drop it off with no idea what the bill will be!!
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Re: burning smell- not the heating

Post by apole » Tue Dec 15, 2009 11:15 am

No worries.

My cambelt was fairly new as well but I figured for the extra cost of £27 it wasn't worth taking the engine this far apart and not replacing it. Now I know I'm set for 100k.

Discount trucks are experienced with this job, it is very involved as there are many things to remove, and of course all the pulleys etc have to be marked carefully for timing purposes so I wouldn't put it in the hands of any old garage.

Good luck and keep us posted.

Andy
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