Is this a coolant pipe ?

mbunting · Post by **mbunting** » 20 Dec 2003, 22:06

Quick history:
94 Xantia TDSX, no air-con, no egr etc.
Head Gasket replaced 20k ago.
Symptoms: Been experiencing coolant leak over the last month or so. Problem is gradually getting worse.
Evidence:
No performance issues.
Fuel economy about average.
Oil appears normal. Not loosing any, and no sign of water.
No coolant pressurisation, except when the engine is genuinely warm ( which is normal ? ).
'coolant' can be seen dripping from under the engine - saw this when recently changing handbrake cables.
Loosing enough to empty the matrix within 40 miles ( about 4L ).
Currently filling with tap water ( I know ), which is leaving signs of leaking on the left hand side of the block, around head gasket level, over the clutch housing, although I cannot be sure as to it's exact source.
Assuming the weather is OK tomorrow ( snow predicted !), I'll be doing the following:
1) Dismantle all inlet ducting.
2) Dismantle all oil piping and breathers.
3) Examine the area around that side of the head.
My question ( "hooray !", I hear you say, and "get rid of it" ) is:
I know of coolant pipes in the following locations:
1) at the front of the head, near the pully ( small pipe ).
2) at the rear of the head, on the left hand side.
3) The thermostat / fuel filter housing.
I have noticed in the dark a small black 'pipe' of some sorts which lies right next to the head gasket. I've only looked in the dark so far, and can't remember if this is a coolant pipe.
Since I have had these problems, I haven't let the car's temperature rise significantly before topping up ( I always carry 4L with me now ), so I'm still fairly confident the head gasket is ok.
Any help and pointers appreciated, so would some favourable weather tomorrow !
On a lighter note, I'm taking a look at auctions. A 1997 P Xantia Exclusive 3.0 ( V6 ? ) auto, good condition went for £1200, while a 406 2.0i executive of the same age went for £1800.

AndersDK · Post by **AndersDK** » 21 Dec 2003, 00:15

On the BX XU engines you have a steel coolant pipe alongside the rear of engine - approx level with the HG. The pipe is part of the coolant supply for the heater matrix.
This steelpipe is known to develop rusty pinholes - even cracks.
I suspect some Xantia engines would have the same layout.

oilyspanner · Post by **oilyspanner** » 21 Dec 2003, 06:27

Ditto Anders reply that steel pipe is the cause of many woes

mbunting · Post by **mbunting** » 21 Dec 2003, 13:48

So many weak spots, why not spend the extra 5 francs making proper kit ?
Mind you, there always has to be a "weakest spot" somewhere !
PS. Any reason why this needs to be steel ? I suppose it's temperature related being near to the block ?

AndersDK · Post by **AndersDK** » 21 Dec 2003, 14:11

Hi again Mat -
I simply think this steelpipe is a production cost issue - as it used to have a couple of distiribution ports & a bleeder screw. Would be more expensive using rubber hoses and several Tee's.
On my spare BX16 engine ready for any replacement event - I've replaced this rusty pipe with a lenght of 22mm dia central heating plastic pipe (spec'ed to 90degC) - the sort used for concrete floor heating. These plastic pipes may be bent to shape using a heat air gun (some 200degC). Pipes are available in a range of standard dia's.
On the CX Douvrin 22 engine - there is an insanely shaped steelpipe reaching under the crank drivebelt wheel - this pipe usually fails in the midst of the winter by the salty roads.

mbunting · Post by **mbunting** » 21 Dec 2003, 16:22

Well, just taken a look.
1) The steel pipe appears to be intact and dry. There is some slight oil coverage around the back from a leaking manifold gasket.
2) The rubber pipe which connects the thermostat housing to the steel pipe appears to be intact, however, I'm going to replace this, as it seems a little perished at the steel end.
3) There are coolant splashes under the air filter housing, and on top of the gearbox, and flywheel. The head from the gasket up is clean, and below the gasket is clean until the casting allows coolant to collect.
4) I started the car, and looked for the cause, during this time, I would say that a cupfull of coolant leaked onto the floor, and it only happens when the engine is running, and it's only from the left hand side of the engine.
So, off to the scrappy to get a pipe, and then to the parts shop to try and get a match !
Might not get a chance to fit it this afternoon, we may be getting some snow here in the peaks area, although is fabulous sunshine at the moment.

oilyspanner · Post by **oilyspanner** » 21 Dec 2003, 17:28

On the other end of the steel pipe lives another short rubber one connecting it to the rear of the water pump, it can be easily seen once the engine is removed and the turbocharger and exhaust manifold are removed! the water pump lives behind the belt covers on the left hand side too and this can display the symptoms you describe, I have even experienced a core plug behind the fule pump leaking, the coolant squirted out hitting the alloy plate mounting the pump, ran down the block and around the flange to drip out directly below the water pump, oh what fun, I would recommend getting the car over a pit or on ramps and running it whilst shining a powerful light, there are so many possibilities here.
Stewart