Ventilation problems - MONDEO

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Sat 12 Jan 2002 20:43
Ventilation problems - MONDEO - Rizwan Basit
I've been noticing for a while that when ever I switch on the cabin fan in my diesel mondeo (95N LX TD) the smell of unburnt/burnt diesel fumes enters the cabin. I've checked the engine bay for any obvious fuel leaks with the engine running, couldn't find any obvious leaks. I was also told at a recent MOT that the front exhaust downpipe was leaking (not a failure point) so I had it changed even though the mechanic who replaced it said there wasn't anything wrong with it. I also replaced the pollen filter at the same time which on removal was quite filthy. Despite this I still get unpleasant smells entering the car particularly with the temperature dial set on warm. I've heard of an electrical problem (resistor?) related to the ventilation system on Mondeos, though I don't think that is the problem here.

Any help would be much appreaciated.

Rizwan
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Sun 13 Jan 2002 11:19
Re: Ventilation problems - MONDEO - David Lacey
It's got to be a fuel leak somewhere in the engine bay..
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Sat 9 Feb 2002 16:45
Re: Ventilation problems - MONDEO - alf
Rizwan,

Similar ongoing problem with my Citroen/peugot disels. Nobody has ever been able to give me any advice, Garage or layman which has cured the problem completely. They all say they can't smell anything!

Cheapest options first:

Double-check exhaust is sound (Some idiot had used a home made paper gasket on one joint)

Change the air filter and check all seals/gaskets/jubilee clips etc around air filter box are tight and made good. (This had the biggest improvement, don't ask me why- I'm not a mechanic).

Check all the engine breathers are clear.

Check leaks from engine bay into the cabin(I used a gas fitters smoke bomb pellet from plumbers merchant) Stick it under the bonnet and get in the car and check for smoke entering.

Check that all the rubber grommets and seals are in place in the engine bay firewall/bulkhead. (the speedo cable rubber had come adrift on mine)
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Sat 9 Feb 2002 16:55
Re: Ventilation problems - MONDEO - alf
Part 2

Steam clean the engine compartment and check for any leaks on engine inc. fuel system.

Check rubber seal on bonnet/Engine bay firewall are sound. and also tailgate seal- I understand that on some hatchback designs low pressure area at rear can suck in exhaust fumes through worn seals. (admittedly renewing these did not make any difference on my car).

A garage suggested I put Radweld in the cooling system as a slight leak inthe heater matrix may cause anti-freeze laden cooling fluid to smell inside the car!!!??

Take out the fuse for the heater fan to see whether the smell disappears.

Someone suggested a slight leak from the injectors which may not be apparent as the fuel evaporates on hot engine without leaving a trace.

Failing that, I remain clueless, let me know if anything works!
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