Xantia V6 broken exhaust (update: and rough low rpm running)

[Mandrake]

Simon, just one question. I know you have added a can of snake oil to the oil but have you actually changed the oil and filter yet?

If you haven't then do as soon as possible and then report back

No I haven't changed the oil and filter yet but will shortly.

As for snake oil, apparently not! I'm as surprised as anyone. As I mentioned we did 130 miles yesterday on top of the 30 miles the day before that, I started the engine cold again today and again the tappets were completely silent right from the moment of starting... so I'm guessing its unclogged the non return valves and is stopping the tappets from draining over night...mind you previously they didn't even quieten down at all after pressure built up so perhaps the oilways were just outright blocked.

After maybe 2-3 minutes of idling one possibly two tappets were a little bit noisy again so its by no means 100% just yet but overall very quiet considering there is just 350mL of whatever it is mixed in with 6 litres (?) of oil...I'm intrigued to see what a good oil change will do.

Do you recall off hand how much oil it takes for a change, including filter ? My converted plastic bottle "oil tray" is only 5 litres and once the side is cut out it just barely holds the 4 litres from the gearbox and no more, so I'll have to find a bigger catchment tray...

[Mandrake]

Also have you checked the oil level in the geabox? If this is wrong I know from experience that it can cause all sorts of funny behavior.

I haven't checked the gearbox oil level in a few months Stempy, but I did check it carefully last time I did an oil change.

I'm not sure how recently you've joined this (admittedly huge) thread, but I've done four oil changes on the gearbox a few months ago and pulled it back from the brink of destruction, it was making awful "I'm going to die" noises there for a while, the first oil that came out was totally black, probably burnt and I thought it was about to give up the ghost on me.

Four changes were required to get the oil back to semi-normal constituency and I think it needs a 5th. Thinking about the way its been behaving lately I think the friction linings on the torque converter lockup clutch are on their last legs, if indeed there is any lining left and its not just griping metal to metal...

It could well be that the gearbox is detecting trouble getting the lockup clutch to lock quickly under high engine torque, perhaps its throttling back the engine torque while it waits for the clutch to lock up. I think the best way to determine that is to see if I can get a scope onto the torque control signal line from the gearbox ECU to the engine ECU and monitor it on some sort of dashboard display or meter... (If its 0 to 5v DC as it appears to be from the manual even a good old moving coil meter movement sitting on the dash would do the job! )

At least I would know whether the lack of power is due to the gearbox commanding torque reduction or not. There may in fact be nothing wrong with the engine now!

[CitroJim]

I was being a bit tongue in cheek calling Wynns Snake Oil Simon. Many years ago when desperate poverty following matrimonial difficulties forced me to drive a rough Volve 340 I found it was the only thing that stopped the big ends knocking. That and cheap 20/50 I knew when it was oil change time as I'd hear the knock.. A change of oil and another can of Wynns finest Snaky stuff and she was good again. I did 20,000 miles in that car before the propshaft fell off but that's another story... I even towed a small caravan with it..

The oil capacity is a tad or so under five litres with a filter. Be aware that the dipstick is a predictor of earthquakes and not reliable. What I do is fill with four litres, start up, let idle for a few moments and then slowly add the last bit until the oil reads right on the stick, waiting a few minutes between top-ups to let it settle.

I'd say a 5 litre drain car was marginal. It might spill a bit. Go to a pet shop and buy a great big cat litter tray to use as a bund. I do and in that way I keep a clean floor. The oil drops out of an ES9 at a fair old rate and will splash and overwhelm a small drain can. The cat litter tray catches it a treat.

The only problem with mine is the tray has a metallic finish and it makes it look like there's metallic particles in the oil. It shocked me rigid once when I drained a 4HP20 into it

[myglaren]

I'd say a 5 litre drain car was marginal. It might spill a bit. Go to a pet shop and buy a great big cat litter tray to use as a bund. I do and in that way I keep a clean floor. The oil drops out of an ES9 at a fair old rate and will splash and overwhelm a small drain can. The cat litter tray catches it a treat.

I use the washing-up bowl then chuck it away and buy a new one.

[CitroJim]

I use the washing-up bowl then chuck it away and buy a new one.

What a waste I make my cat litter trays last years. I was heartbroken when my last one got destroyed in a hub-nut incident. I'd had it about ten years...

[myglaren]

I always have one available Jim, it is a good excuse to renew it periodically.
The capacity is ideal too.

Have no cats , ipso no cat litter nor trays.

[CitroJim]

Ahh, now I understand Steve. That's why I only change washing up bowls when they start falling apart then

I have a cat but she has no idea what a litter tray is. She has the whole neighbourhood for that In fact I can think of nothing more vile than a litter tray being used for its intended purpose

[Stempy]

Ahh, now I understand Steve. That's why I only change washing up bowls when they start falling apart then

I have a cat but she has no idea what a litter tray is. She has the whole neighbourhood for that In fact I can think of nothing more vile than a litter tray being used for its intended purpose

I can think of nothing more vile than someone elses cat digging up and sh1tting in my garden, thankfully I have a dog that is well trained to hate cats.

I am also a fan of the washing up bowl method.

[Stempy]

Also have you checked the oil level in the geabox? If this is wrong I know from experience that it can cause all sorts of funny behavior.

I haven't checked the gearbox oil level in a few months Stempy, but I did check it carefully last time I did an oil change.

I'm not sure how recently you've joined this (admittedly huge) thread, but I've done four oil changes on the gearbox a few months ago and pulled it back from the brink of destruction, it was making awful "I'm going to die" noises there for a while, the first oil that came out was totally black, probably burnt and I thought it was about to give up the ghost on me.

I haven't really kept tabs on the thread until recently but was getting bored having a car that doesn't require constant attention so I thought I'd join in. In fact I'm considering buying a C5 estate to replace my Renault van so still have an interest in vehicles of a French persuasion.

[Mandrake]

I haven't really kept tabs on the thread until recently but was getting bored having a car that doesn't require constant attention so I thought I'd join in. In fact I'm considering buying a C5 estate to replace my Renault van so still have an interest in vehicles of a French persuasion.

If you're bored of cars that don't require constant attention, you've come to the right thread...

[Mandrake]

Well it looks like oil changes, new thermostats and other goodies will just have to wait for at least a month.

We're going to look at a house in a couple of weeks and if we get it every penny will be going towards moving, so all expenditure on the car except petrol has been vetoed for the next month or two by she who must be obeyed.

Fortunately apart from being intermittently down on power the car is running acceptably well with no urgent "must fix before it falls off" issues, touch wood.

So I guess the intermittent low power may have to remain a mystery for the time being...sorry guys

PS when driving the car yesterday (from cold) most of the zip had returned again, although it was slightly intermittent - very zippy sometimes a bit more hesitant others.

Possibly there are two related but separate issues.. one causing intermittent hesitation / lack of responsiveness, and a second issue that causes a constant loss of power across the board after the car is well and truly warmed up (at least 30-40 miles or so driving) the latter of which I suspect could be related to high oil temperature in the gearbox causing the gearbox to throttle back the engine torque to protect itself.

Next time I go for a long drive I'll try to get maximum temperature readings of both the coolant and gearbox oil with the Lexia to see if either of them are unusually high...for example if the coolant is 10 degrees too high it would lead the gearbox oil to be 10 degrees too high (eventually) also, which might be nudging it into the temperature range where it starts throttling torque back. As there's a lot of thermal mass in the gearbox it would take a lot of driving (half an hour / 30 miles or more) at motorway speeds to get the gearbox up to maximum temperature.

(It takes a good 15-20 minutes on a fast country road to get the gearbox oil up to only 80 degrees for an oil change, let alone up to 105 degrees or so which it can reach on prolonged motorway driving)

Just a thought Jim, is there any chance the water side of the heat exchanger could be blocked, or that the heat exchanger is not working properly for some reason ? (An air lock in the coolant side of the heat exchanger maybe ? If that's even possible) I assume the heat exchanger is on a separate coolant loop that bypasses the thermostat, much like the cabin heater ?

Also I plan to try to tap into the torque reduction control line with a small digital scope as a kind of heads up display on the dash which will tell me one way or another whether a signal from the gearbox is reducing engine torque when the performance is flat...

[Hell Razor5543]

I have just had a nasty thought. Some time back there was an argument about radiator repair additives that you added to the coolant. CitroJim was emphatic that you must not use them on a V6, as they knackered the gearbox cooler. I REALLY hope that nobody has used that on your Xantia!

[CitroJim]

That is correct James but if the cooler is blocked or otherwise not circulating then by now your gearbox would literally be toast Simon! HP20s do not like running hot.

Easy to test, just feel the return hose from the cooler - the hose that disappears into the bottom of the rad. And indeed the cooler is on it's own circuit; a similar one to the heater matrix.

[lexi]

That is it for you now Simon. Wallpapering, plastering, painting, and sanding. You will be like a snowman most nights as you join a world of laminated everything!! Put your scope and spanners away and get the moisture meter out with the hawk and trowel to be covered in dust for months..........and a fork for the garden

[Mandrake]

Not so fast Alex, its a rental not buying