Are XU7 engines known for head gasket failure?
My wife drives 1995 XU7 1.8 8v Sedan that has given no problems to date (great car) but I decided to drive it to the airport to give it a decent motorway run yesterday. Starting it up from overnight cold it ran on three cylinders for a second or so as it staggered up to idle, and then cleared on to all four. Normally it leaps up to 1300RPM and then drops to 1050 RPM before then dropping back to 850RPM over time.
Having reversed out of the garage, in the headlight beam I could then see a small puddle of water on the floor roughly level with where the gearbox/engine join would have been. (i.e between the front wheels, left of centre) Dipping my finger in and licking revealed the characteristic taste of antifreeze.
The car drove perfectly to the airport at the normal 88 deg C on the gauge and with plenty of poke, but the instant I slowed down the gauge went to 92 deg C and the fan cut in.
I left the car at 04:50am in pitch dark without being able to check the water level, and will return to it tonight at 11:00pm also in pitch dark. Of course I will have water with me as I expect to need it!
Back to my question though; likely HG failure?
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Water leak could be from water pump if you say it was slightly left of centerline front wheels. I presume whilst looking towards front of car?
Check for other symptoms of blown/leaking head gasket such as;
excessive watervapour/steam from exhaust pipe - even with engine fully warmed up.
Oil/water emulsion ('mayonaise') under oil filler cap.
Water droplets/'mayonaise' on oil dip stick.
Oil droplets or sludgy oil/water mix in expansion tank.
Oil leaks from cylinder block/cylinder head joint. (Can be tricky to spot as these engines can weep oil from rocker cover gasket which then spreads over back of engine)
With engine running, look for air bubbles in the expansion tank and signs of pressurisation even on a cold engine. But DONT open coolant expansion tank with engine hot!
Most garages carry out head gasket checks by taking a sample of coolant from expansion tank and either using a gas tester to look for combustion gases in the water or mixing a small amount with a chemical that changes colour (usually turns green) if combustion gases are present. This should take no more than 30 mins if a garage tests it.
Be careful when tasting antifreeze even if its a small drop as this stuff is poisonous and can cause nerve damage/blindness.
Andrew
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Thanks Andrew. I will of course do those checks during daylight at the weekend (Wife and I won't need to use the car in the mean time) but made the post in light of the fact that I will return to the car in a pitch black car park (where it looks like it will also be raining so I can't look for puddles underneath) and then drive it home in the dark. All this means checking causes at Luton Airport will be a bit tricky! The only light source I have is the bright glow from my cellphone.
I only thought "headgasket" as the car stuttered on startup which it has never done before and to me this was more than coincidence; the engine bay including block is kept as clean as a whistle and I know had not a single weap or leak at the weekend when last cleaned. I also know that it has not been "wetted" so damp electrics or water in spark plug recesses are unlikely to have cause the initial stutter.
The waterpump is about a year old.
The puddle as I wrote is from the gearbox end of the car; i.e. lefthand side when sat in the driving seat, aka nearside, so not the waterpump end. I mentioned it incase the XU7 was known for HGF or leaks at this end of the radiator or engine, though of course water can travel before it drips so guess the leak could be anywhere.
Looks like all I can do is take the expansion bottle cap off and have a squint with a cold engine using cellphone illumination! if low, top up, warm the engine with the cap off, and squeeze upper radiator pipe to force air out. Keep topping up, and when expansion bottle level drops no more, put cap on and drive straight home!
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Hope you got back from the airport last night!
The 1.8 is not known for HG failure, and in most cases this would be unlikely to lead to loss of coolant direct to the floor. The radiators on 306s are not exactly the longest lived items, and a leak from here could leave a puddle where you described. I was trying to figure out, though, why this should have had an effect of the starting, but couldn't - until I remembered that the coolant temp sensors are on the thermostat housing, which is right above the engine / gearbox join! I wonder if one of these has gone kaput, is leaking, and not giving the ECU the correct signal for the cold start routine.
Let us know what you found in the dark last night!
--
RichardW
Is it illogical? It must be Citroen....
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Greetings, fellow BRers, and thanks for the comments.
What did I find in the dark at Luton airport last night?
The honest answer?
...no problem!
On returning to the car in pitch black, with some trepidation I popped the bonnet and unscrewed the expansion cap which of course along with the expansion tank is on the nearside end of the radiator. As planned, switching on my cellphone as a light source I then squinted in to the tank and saw that the water level was only a couple of centimetres below normal and there was no visible water contamination.
"Hmm", thought I.
A further "HGF symptoms" check showed the dipstick to be seated correctly and not blown up a few millimetres as I have previously seen happen on a friend's car when HGF resulted in oil gallery, and consequently crankcase, overpressure.
A further "Hmm", thought I.
The oil looked clean and of correct level, so with fingers mentally crossed I turned the ignition key; the engine started "instantly", on all four cylinders and with normal smooth ECU controlled cold start regime. A quick check under the bonnet showed no ignition lead arcing, cold leaks, or other problems, so I set off in to the night for a totally event free drive home.
After leaving the last stretch of empty dual carriageway having driven for fifteen miles or so at 80-85mph and with temperature gauge resolutely at the normal 88 deg C, I pulled over and stopped, engine idling. Within a couple of minutes the gauge was at 92 deg C and with cooling fan running, exactly as when arriving at the airport and spending a couple of minutes finding a bay and parking up; I guess this is just normal underbonnet heat build-up outside normal use - and therefore my experience - of this car, to be excluded from any "Monday morning coincidences".
At home later, opening the garage door showed a clear fresh stain where the coolant puddle had been so I placed a clean piece of paper in the same spot and parked the car; I am lucky to have stacks of space in the garage in front of the car so before next reversing out I will check the paper and then work up to establish the drip-point.
Thankfully we don't need the car again until Monday as the first opportunity I have to do this will be the weekend; perhaps your educated guess to connect the symptoms will be proven correct, Richard.
To be continued...
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... Continued as promised.
This has turned out to be one of life's mysteries.
A thorough check at the weekend with the car up on axle stands showed no sign of any leak anywhere. Although the coolant in the expansion tank was slightly down - I know it was bang on maximum when cold checked a couple of weeks ago - I could find no evidence of where it had been lost from. Not even any tell tale powdery white stains on this clean engine. The reduced level was the same as when checked at Luton Airport and had not fallen further.
The coolant puddle on the garage floor came from a drip on the engine lefthand subframe just inboard of the lower suspension arm so the source could be widely located, but at least radiator and front hoses are ruled out. This made me think of interior heater pipes but I can find no problem without stripping the dash out and carpets are dry.
The coolant in the expansion tank was nice and clean with no oily streaks and the engine oil level was bang on maximum and golden clean.
Since this check the car has been driven several hundred further miles often at motorway speeds and hasn't lost a drop of liquid or missed a beat. Cold starting, even after leaving out in the frost instead of garaging has been of the usual instant and well controlled nature.
Murphy of course says the problem will reveal itself when the missus is on her own and I am next working in KL and Shanghai in a few weeks time!
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