Water Hose - Rear of Engine Bay

scam75 · Nov 25, 2020

Evening chaps

Had a strange old day today. Stripped out the blower motor only to find it very smooth and quiet. One of the leathery things that shuts off outside air for recirc was completely detached and worse for wear. Did a bit of a Heath Robinson on it and put it all back together and all was well in blower land. Possibly the loose thing had been rubbing against the blades? Dunno. Anyway was loading up the boot for a dump run with engine running and started getting steam out the bonnet. Couldn't see anything from the top with a torch but looks like a burst water hose down low between engine and bulkhead. I assume there will be an in and out for the heater matrix there?

Anybody got previous with this? Don't think I've ever touched a water pipe round there and I can only imagine skinned knuckles and lots of swearing at this point!

Thanks in advance

Stuart

chrisg · Nov 25, 2020

Hi Stu

It's funny you should say this - I was only looking at these pipes on my turbo last week just before I put the inlet manifold back on. Yes, there's a number of short curved pipes that connect the back of the cylinder head with an adjuster valve for hot water in the heater matrix. I've not tried changing one before - best to undo the run sensor holder bracket and try it from there. Of course it will be much easier with the IM removed but that does seem a bit extreme.

I remember a similar hose bursting on an E36 328 on a friends car at spa - we managed to bodge it back together for the journey home.

Hope this helps,

C

scam75 · Nov 25, 2020

Thanks Chris. I checked PET and there seems to be loads of water hoses, identifying what one has let go is the first step I suppose! It is more likely to be accessed from top or underneath? Again I suppose I won't know till I find the culprit. Very annoying at this time of year as I don't have a garage or ramp.

Stuart

Eldavo · Nov 25, 2020

There’s a hose that goes from the block to the heater matrix - it comes out of a plastic vacuum valve. If the valve cracks, then all the coolant gets pumped onto the turbo downpipe with the resulting massive billowing clouds of white coolant and an erm . . . early lunch track closure. [8|]

If it’s the valve then it’s about £60/70 from Porsche or under £20 from Mercedes.

scam75 · Nov 25, 2020

Thanks Dave. That's the feed in to the matrix (I think, according to PET!), I thought it may be a culprit. Need to check in daylight tomorrow. Mine was sitting at idle, in the wet, and at first I thought it was rain evaporating on the bonnet before it got a bit much for that phenomenon! Somewhere about there the failure is, was defo hitting exhaust. At least no tracks needed attention other than those of my tears!!

Easy enough to access Dave?

Stuart

Eldavo · Nov 25, 2020

I managed to bypass it with a hot engine at the lunch break of a track day. With a cold engine, the luxury of time, and maybe some zip ties to hold the wires out of the way then it should be a relative doddle.

Eldavo · Nov 25, 2020

If it does turn out to be the valve itself and not a pipe then this is what you need, common to an Audi 80 and a Merc 190e amongst others:

https://www.ebay.co.uk/itm/203097234394

scam75 · Nov 26, 2020

Thanks Dave. It turned out to be the pipe that goes from the metal elbow to the valve you mention.

Got it off without much problem with use of a 6mm socket and an elbow and an extension. Valve was ok, pipe had a cut visible and also some more imminent failures upon inspection and was a bit bloated, 32 years and 161k miles, poor thing. After undoing the jubilee clip, I retracted the socket and the knuckle and 6mm detached themselves after dunting on one of many obstacles in the area. Had a look underneath, nothing, so was going to fire it up and rock it a bit, see if the tools fell out. Can anyone guess what happened next? Nearly a gigantic cluster**** of course, nosed myself round the other side, torch in hand, to see that said knuckle and socket had entered the bell housing inspection port, and lay precariously on top of the flywheel! [&:] . Unbelievably, as the knuckle was bent into a L shape, it had managed to jump through the hole onto the flywheel. This meant that getting it back out with a magnet, was near impossible as it fouled both sides of the aperture as I shat myself it was going to fall down into the bellhousing. Close to tears does not sum it up! [:-] .

So I went round to my local mechanic to borrow a 2nd magnet. Now, 2 magnets together, inside the gap, cannot be removed at the same time as too large for the gap. Plus the fecker knuckle was too large also to come out. I somehow managed to get the 2nd magnet on it, then remove first magnet without dropping it, then was able to get that magnet round the other side of magnet 2, lift it slightly so when I got magnet 2 off it, I could flip the knuckle so the magnet grabbed the end of the 6mm socket, in a vertical manner. This meant I could raise it mostly out the hole, but was still faced with the bent knuckle fouling the aperture. To my amazement I managed to navigate it out. The feeling here can only be described as probably better than a multiple orgasm!

. And to think I was absolutely rubbish at the kids game Operation when I was little. A lucky, lucky, lucky escape!

Then went round to my other mate who handily had some water pipe with an elbow of the correct diameter, and he cut me the right size. Another PITA re-assembling, this time with inspection hole blocked. Careful not to overtighten and crush the plastic valve and it's all back together and leak free. Cost me a total of one litre of antifreeze! Bled up no bother upon refill, seem to be good at that now!

I will consume lots of beer this evening!

Cheers

Stuart