My '90 S4 was in for the 100k service, all done, ticking over before test drive .. then whoosh! .. Fire! .. FIRE! .. Its out! .. Phew!
click for larger image

The fire was caused by the failure of the fuel transfer hose from one side of the engine to the other at the top front.

On examination it was found to consist of a two layer rubber hose, without re enforcement. This is highly unsatisfactory and downright dangerous. I do have the engineering experience to make this statement.

It is vital that all owners replace this hose immediately. If you can't afford it, leave your lovely shark in the garage till you can. Running a non re-enforced hose with a 70 psi flammable product is foolhardy in the extreme. Especially now that these hoses are 10+ years old and  getting brittle.

The type of hose; it is marked H LINE 3700800 (-3-1-0088 0 this is not clear) The hose end is marked 'COH West Germany' Where it connects to the vehicle, The type of failure, simply rubber parting at the hose nipple, bad stuff!

Other Vehicles

You can't breath a sigh of relief if you find you don't have this model or this hose. It seems this type of hose may have been used on other models so have a very critical look. If you find a fine parallel ribbed outer surface type rubber hose in petrol service, check if you can read the ID on the hose or the end ferrule. If for example it is the same, out it goes .. urgently .. no stuffing around .. just get rid of it!

It is also a suggestion to replace any petrol pressure hose with a racing spec unit. For these heritage cars they deserve your best care.

Standing at the side of the road as your beautiful shark burns to the ground will haunt you and all of us for the future, so act now guys. We got the  warning. Mine escaped because the workshop is run by professionals and they had extinguishers ready right next to the car.

Act now .. call me if you need discussion

Cheers, Bruce Wilson '90 S4 (still, thank goodness).
Bus: 02 9450 1962 
Ph: 02 9913 1393