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

[addo]

I would aver that Australian fuel is of lesser quality than UK fuel, yet one can go 120000km typically before injectors have any noticeable deposits on them. By that I mean worth cleaning off.

[stevieb]

Coincidentally, the use of injector cleaner by a main dealer at a 10,000 mile service maybe speaks volumes, don't you think?

Yes, it simply says that they can get away with selling mugs any old crap they are told they need. No more, no less. They probably buy it in bulk for a couple of quid a bottle, easy £11 made on every service.

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It wasn't optional though - it's quoted as part of the 10,000 miles service in the service book...

[Northern_Mike]

Coincidentally, the use of injector cleaner by a main dealer at a 10,000 mile service maybe speaks volumes, don't you think?

Yes, it simply says that they can get away with selling mugs any old crap they are told they need. No more, no less. They probably buy it in bulk for a couple of quid a bottle, easy £11 made on every service.

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It wasn't optional though - it's quoted as part of the 10,000 miles service in the service book...

It's not mentioned *at all* in *any* of Toyota's servicing schedules on their website..

http://www.toyota.co.uk/service-and-mai ... -servicing" onclick="window.open(this.href);return false;

No mention at all of injector cleaning whatsoever.

[stevieb]

Before you get too hot and bothered Steve I think you're misinterpreting what addo was trying to say. He's saying the erratic performance you were seeing isn't going to be a result of variations in the quality of the fuel from one filling to another, he doesn't mean as the result of variations in the fuel PUMP in the car, eg fuel pressure. I'm not sure that I agree though as I have sometimes seen significant changes in behaviour with different fuels.

That's why I tried to cover both possibilities in my answer

I DID take Addo's comment as confrontational though, especially as a LOT of people's experience says otherwise.

There's no "low power mode" on this ECU that I'm aware of. If you lost power but the MPG actually improved I would say your engine was possibly running lean. Lean running up until the point where it starts misfiring and/or knocking (causing timing retard) will give better MPG but worse performance. Normal steady cruising is stoichiometric in closed loop mode with the O2 sensor, but stoichiometric is not optimal for MPG, its only optimal for the CAT performance and lifetime.

Are you sure you don't have an intermittent fault with your O2 sensor ? A faulty O2 sensor does NOT trigger the engine management light on this engine and causes very little observable symptoms. If the O2 sensor fails the ECU runs in open loop mode all the time which will run the engine slightly rich all the time - so an unplugged / faulty O2 sensor gives worse MPG (and would fail an emissions test) but actually gives better performance. Unless you've measured the O2 sensor while driving like I have you would never really even know that it wasn't working properly sometimes.

I'm not sure about the "low power mode". There's certainly a limp-mode (many Coupé Club members have suffered it with the matching trip computer warning). As for the O2 sensor on mine, that'd be one step too far for me to bother changing. My MoT is due in April - if it fails on the emissions due to the oxygen sensor then it'll be off to Peugeot heaven and I'll be buying the next car sooner than planned.

Regarding vapour lock in the fuel rail - I'm not sure that its causing an issue for us (or me at least) while driving but I DO think that it's the cause of the intermittent near stall/surge cycles when starting a HOT engine that has sat for 10-30 minutes after being switched off.

This seems to be a relatively common problem on the ES9J4, I've certainly seen it discussed on here before - start a hot engine after it has sat for 10-30 minutes and it will struggle to start, drop below idle nearly stalling, surge up to about 800 rpm, drop below idle again, surge up again, and repeat this maybe three times before it finally settles down and becomes stable. Mine does this quite often but not always. I think where the intermittent nature of the problem comes from is that the non-return valve in my fuel pump is a bit intermittent. During my testing in the shed with my original fuel pump sometimes it seals and holds rail pressure for a long time after the pump is turned off (10-20 minutes or more) and sometimes it leaks away quickly in under a minute. I guess the ball valve is worn out.

If the pressure leaks away quickly after the engine is stopped and while the engine bay and rail is still hot the fuel in the rail and injectors can boil (especially if its a volatile winter grade fuel on an unusually hot day for the time of year) and cause a vapour lock condition. When you try to start it struggles to run due to the vapour lock which is not cleared until the fuel pump has circulated cold fresh fuel from the tank. If the pressure in the rail is held for a long period of time after switch off, until the rail gets time to cool down below the critical temperature, no vapour lock occurs and the car starts easily.

Thinking about it I now understand why the fuel pump is briefly activated every few minutes after switch-off for some period of time - to try to keep the fuel rail pressure topped up until the rail cools sufficiently and avoid vapour lock occurring! Of course if the pump only runs for 2 seconds once every 5 minutes for a total of 20 minutes and the pressure leaks away after 30 seconds then vapour lock will still occur.

I'm pretty sure both my original pump AND the replacement second hand one in the car now have problems with the non-return valve intermittently leaking back, so I think other than a brand new expensive fuel pump the only way to solve this issue 100% would be to insert an external non-return valve in the line between the pump and the rail. (on either side of the fuel filter would be the ideal place) There are plenty available for not much money the only problem is trying to safely splice it into the fuel line without cutting and hacking the line. (Finding one that has the PSA snap lock connectors would be ideal - most just have spigots)

I don't have any of those symptoms in those same circumstances, but I sometimes have that yo-yo-ing of revs on a warm engine at tickover (often at the end of a motorway sliproad after a long journey - i.e. when the engine is hottest) where the revs dip to a near stall then pick back up about five or six times. It usually passes within a few seconds and only ever happens once on a journey. I'm convinced this is something pressure-related, but whether it's vapour-locking is another matter.

Something else I cured with the cleaning of the fuel pump connector was the throttle blipping itself up to 1200rpm when slowing to a stop (I've checked to see if it's the PAS pump adding load and it isn't that) - this problem returned after I had that change in noise the other week, but hasn't been back since Sunday's other change in noise.

But do you fill with 99 V-Power or 95 ? Are you suggesting they put a bit of left over 95 into the 99 tank before the tanker arrives, or the other way around ?

I only use 95RON these days. I haven't used V-Power or any other high octane stuff for months now. Like I say, I wonder if some of my variableness is simply varying octanes and additives from different brands. The recent deterioration has happened after a number of consecutive visits to Shell garages with no other brands in-between. I'll see how things behave tomorrow now I've got some Esso in.

Oh, and the garages add the 99 into the 95 tanks. They're not allowed to sell 99RON fuel that has been diluted down with 95RON, but they CAN sell 95RON that has been diluted with 99RON. The volumes involved are usually minimal and not everywhere does it, but where they do it means there may be some variability in 95RON stuff.

[stevieb]

It's not mentioned *at all* in *any* of Toyota's servicing schedules on their website..

http://www.toyota.co.uk/service-and-mai ... -servicing" onclick="window.open(this.href);return false;

No mention at all of injector cleaning whatsoever.

Dunno. It was listed in the book as part of the 10,000 mile "first service".

EDIT - Girlfriends service was a fixed price of £130, not the £99 listed in that link. She's going to query it with the stealer and ask precisely what was put in the tank - apparently her car has been running like a dog again this evening.

EDIT 2 - "Serviceplan" is the key word. She's still gonna see what on earth they tipped in the tank though...

[addo]

I am confrontational. It simply means I may state my opinion firmly and clearly.

There's no room for snake oil fixes in my work, I have seen some "experts" cock things up, lie to customers, lack knowledge and (worse) lack the will to remove these knowledge gaps. I'm self employed and paid on results, there's no invoice prior to that point. A result can be a completed report with evidence attached, or a physical fix.

If an injector cleaner was so marvellous it changed the running of a car from good to better, or from bad to good in just one application, it would be immensely strong! You only have to put an injector under the stream from a parts washer nozzle to see how long it takes to start lifting varnish, and that's without combustion putting it back on.

Similarly, if the mapping of an ECU was so tight that fuel with an RON at or just below the legal minimum would give it fits, the world would be awash with complaining people as their cars stuttered and staggered. Generally what happens with poor quality fuel is there is greater consumption all over and less of an "edge" to the top end performance as it runs out of octane - in the middle range there is adequate compensation in the mapping and it just increases fuelling.

An interesting recent failure was an ECU that had had (accidentally) a positive short to ground through the case. Now - the case is not separately grounded, so the current passed through the ECU pins, to the harness, to ground. It melted solder holding the ground pins to the ECU. Eventually, the beads of melted solder came loose and all grounding was lost - this resulted in the case having a 4V standing wave on it (which I noticed purely by accident as I had already checked the harness grounds). Symptoms earlier in use of this affected vehicle had been occasional misfiring, poor performance, the odd no-start, then back to normal - and the Lexia diagnosis did not really offer much insight.

Why do I mention this? The first bloke to look at it, was certain it was rubbish fuel.

[Northern_Mike]

I've never had problems with any car with rubbish fuel. Sure, the 1.8 Passat I used to run on petrol with a high ethanol content in Brazil was down on power compared to the imported German one we had as well but ran on real petrol, but it still ran ok. I had a blocked jet in the DRK carb recently but I think that was crud from the 30 year old tank. It's not happened since. All my cars run off Asda, Sainsbury or BP fuel depending on where I am when I need to put some in.

Never had a fuel quality related problem in 25 years of driving and it's always been cheapest available. In Brazil, Greece, Colombia and UK to name a few.

I believe that if supermarket fuel were so bad there would simply be dead cars everywhere! There isn't, and the fuel all comes from the same places anyway. Some branded stuff has more detergent in it but that's about all. The fuels also have to confirm to a BS or EU standard too.

I'd be more interested to know if fuel systems were designed to work with all these detergents and chemicals being pumped through them. If this stuff really can dissolve varnishing with 500ml in a 60l tank, then it must be the most powerful solvent every, and be doing untold harm to our engines, sensors, cats and seals.

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[stevieb]

I am confrontational. It simply means I may state my opinion firmly and clearly.

Except you didn't state an opinion. I expressed a FACT as I (and many others) see it in my post and you either called me stupid or a liar. That's why it was confrontational.

There's no room for snake oil fixes in my work, I have seen some "experts" cock things up, lie to customers, lack knowledge and (worse) lack the will to remove these knowledge gaps. I'm self employed and paid on results, there's no invoice prior to that point. A result can be a completed report with evidence attached, or a physical fix.

If an injector cleaner was so marvellous it changed the running of a car from good to better, or from bad to good in just one application, it would be immensely strong! You only have to put an injector under the stream from a parts washer nozzle to see how long it takes to start lifting varnish, and that's without combustion putting it back on.

I suggest you look into a product called Terraclean and the real-world results it has given. No snake oil, no bull. Real people who's cars have been given a new lease of life with "one application" to the fuel system.

Similarly, if the mapping of an ECU was so tight that fuel with an RON at or just below the legal minimum would give it fits, the world would be awash with complaining people as their cars stuttered and staggered. Generally what happens with poor quality fuel is there is greater consumption all over and less of an "edge" to the top end performance as it runs out of octane - in the middle range there is adequate compensation in the mapping and it just increases fuelling.

I'm not sure anybody suggested fuel dropping below RON. There are umpteen reasons why fuel can be "bad" that don't directly affect the RON figure. Additives can be added in incorrect ratios. Additives and fuel can go stale. Storage tanks can become contaminated with other fluids, not to mention foreign bodies (rust, microbes, anything else you care to mention). All these things can cause problems that won't necessarily cause a car to "stutter and stagger", but may cause other issues that may build-up over time and cause problems in some cases - blocked fuel filters, grit in injectors and pressure regulators, or may just cause one immediate failure...

An interesting recent failure was an ECU that had had (accidentally) a positive short to ground through the case. Now - the case is not separately grounded, so the current passed through the ECU pins, to the harness, to ground. It melted solder holding the ground pins to the ECU. Eventually, the beads of melted solder came loose and all grounding was lost - this resulted in the case having a 4V standing wave on it (which I noticed purely by accident as I had already checked the harness grounds). Symptoms earlier in use of this affected vehicle had been occasional misfiring, poor performance, the odd no-start, then back to normal - and the Lexia diagnosis did not really offer much insight.

Why do I mention this? The first bloke to look at it, was certain it was rubbish fuel.

That doesn't mean bad fuel doesn't exist. Just that that bloke was a clown. Let's be honest, you only found the problem by accident. What was your diagnosis before you found it, and how high up your list of probability was a short in the ECU case? Not very high, I bet.

I'm not saying bad fuel is definitely the answer in our case or any other, merely that there are coincidences here. And it seems that in my girlfriend's case the combination of injector cleaner (which you really wouldn't expect a 12 month old/10,000 mile car to need) with Shell fuel has created problems. It might turn out to be only be one of those factors, or neither of them, but I regularly use Shell, and I know Simon does too - and that's why I asked the question. If three of us with possible Shell fuel problems switch to other brands for a week and notice improvements, then it's fair to say it might be the fuel at fault. Hey, maybe Shell have changed the formula - there's no shortage of food companies who are happy to mess about with ingredients without telling us (from somebody who tries to avoid artificial sweeteners, I'm acutely aware of this).

Just like Simon, I'm an amateur clutching at straws trying to keep my car on the road and get the best out of it. I don't have big money to spend on it, and if I did have big bucks to spend I wouldn't be driving this car anyway. I DO believe in sharing information that might help us pool ideas and find solutions. If that gets on anybody's nerves, then I apologise.

[stevieb]

I believe that if supermarket fuel were so bad there would simply be dead cars everywhere! There isn't, and the fuel all comes from the same places anyway.

A challenge. Run five tanks of supermarket fuel, brim-to-brim, noting your refills and your mileage, and using this data to precisely calculate your fuel consumption.

Then repeat with big-brand fuel.

I guarantee you'll see an improvement in mpg with the branded fuel.

Time and time again people try this and see the difference, but sadly, when it comes to filling up convenience wins. And they choose the supermarket

[Northern_Mike]

I am confrontational. It simply means I may state my opinion firmly and clearly.

Except you didn't state an opinion. I expressed a FACT as I (and many others) see it in my post and you either called me stupid or a liar. That's why it was confrontational.

No, you expressed an opinion, not a fact.

Addo called you neither stupid nor a liar. He said you were wrong. I'm inclined to agree with him.

[Northern_Mike]

I believe that if supermarket fuel were so bad there would simply be dead cars everywhere! There isn't, and the fuel all comes from the same places anyway.

A challenge. Run five tanks of supermarket fuel, brim-to-brim, noting your refills and your mileage, and using this data to precisely calculate your fuel consumption.

Then repeat with big-brand fuel.

I guarantee you'll see an improvement in mpg with the branded fuel.

Time and time again people try this and see the difference, but sadly, when it comes to filling up convenience wins. And they choose the supermarket

How does "no, I've got seriously better things to worry about and do with my life" sound as an answer?

I fill up where it's convenient. Sometimes that's BP. Sometimes it's Sainsbury. Sometimes it's Asda. BP is about 1.5 miles from my house, Sainsbury is next to my office, Asda is 8 miles from home.

I have *never* seen an improvement using branded fuel in the Berlingo, in fact, I can honestly say the best mpg I got from it, 51.4, was on Asda fuel when we went down to Cornwall in it last year.

Being a competent driver, and being able to drive economically makes far, far more difference than changing fuel will ever do. That's if it makes any at all.

So far, all your speculation is based on snake oil injector cleaner and Terraclean - yes, I have seen the ads. Has anyone ever told you how it works though? Can you find this information anywhere? Can you find out what's in it? I bet you can't. I certainly couldn't.. It's yet another con that works via the placebo effect.

[Northern_Mike]

I DO believe in sharing information that might help us pool ideas and find solutions. If that gets on anybody's nerves, then I apologise.

Actually, to be honest, yes, it does. It's perhaps the most tedious thread ever. I wish I could block it, but the way the forum scripting works, I can't, and I'd rather not block anyone as a)it's rude, and Simon is a nice guy, and he is helpful in many, many other matters, and b) Even if I did block someone, the forum scripting tells you that blocked people have replied, and the thread still ends up at the top of the list. As it is, it's about 3 pages of useful info, and 102 of speculation and bizarre reasoning. No one actually seems to want to fix the issue, there's been plenty of offers of help from the boffin crowd if it was brought down for a weekend... which by now would have been far cheaper than the amount of stuff that's been bought to not solve the problem.

[RichardW]

Can you turn off replies to a specifc thread, Mike? No idea, I haven't got that turned on.

I've met with Simon and worked on his car - he's more than competent to fix this, and if it was something simple he'd have fixed it by now. OK, he likes to write (at length!) about it, but that's his perogative

[addo]

Stevie: Recent ECUs are utter pigs to open up, as the lid is thin pressed metal totally bonded with a non-elastic polyurethane and the unit itself is shielded in a case with tamperproof (shear-off head) screws. Even with a professional heat gun to soften the urethane, you make a mess of the lid edges.

For the HDi in question, I had arrived at the point of confidently saying "There is a fault inside the ECU, it is not getting any power to the board" and was waiting on a call about a replacement used set when I happened to observe the voltage - first I thought I saw a spark out the corner of my eye when shuffling the ECU box in the engine bay, then as the meter was to hand, probed the case for continuity - my multimeter flicks the screen if there's a standing voltage when you're measuring resistance - a very handy warning system. The rest is history, but I think the garage - who had first suspected the fuel to be at fault - will not make that diagnosis again in a hurry.

[Mandrake]

I DO believe in sharing information that might help us pool ideas and find solutions. If that gets on anybody's nerves, then I apologise.

Actually, to be honest, yes, it does. It's perhaps the most tedious thread ever. I wish I could block it, but the way the forum scripting works, I can't, and I'd rather not block anyone as a)it's rude, and Simon is a nice guy, and he is helpful in many, many other matters, and b) Even if I did block someone, the forum scripting tells you that blocked people have replied, and the thread still ends up at the top of the list.

Mike, respectfully, it's been a VERY long time since any of your comments in this particular thread were of a constructive nature, and it does get a bit tiresome to be heckled by someone who is not making any constructive comments, when I am busting my behind making a serious effort to solve this problem. (or problems) This is my thread, not yours.

If this thread bothers you so much, may I politely suggest that you un-subscribe from it and resist the urge to click on it in the thread listing. Nobody is forcing you to read this thread. I ignore certain threads which are of no interest to me all the time and am not tempted to click on them even during a "slow news day" on the forum...

As it is, it's about 3 pages of useful info, and 102 of speculation and bizarre reasoning. No one actually seems to want to fix the issue, there's been plenty of offers of help from the boffin crowd if it was brought down for a weekend... which by now would have been far cheaper than the amount of stuff that's been bought to not solve the problem.

I find your suggestion that "no one actually seems to want to fix the issue" quite insulting given what has almost certainly been the single most persistent, dogged attempt to solve a tricky problem (or problems) ever seen on this forum - I have literally busted my ass both mentally and physically trying to solve it, well past the point where most people would have given up and admitted defeat.

As for "turning down" offers of help from the "boffin" crowd, you are seriously mistaken if you think an 800 mile round trip and one (or even two) days looking at this car would have resulted in a miraculous diagnosis and cure - not a chance in hell, especially knowing what I know now in hindsight and what has since been done. At the very least the intermittent nature of the problem(s) would have made a 24 hour diagnosis impossible, no matter how talented the boffins. At the time the car could run for days without problems and any attempt to do any work on the car - even removing and refitting the air filter box inevitably affected the running of the car and caused it to seem to be temporarily cured.

So I would drive 400 miles each way to have the car tinkered with, find either that the symptoms weren't there when I arrived or were "fixed" by some random tinkering, only to return a few days later after I was home again. That's assuming that an 800 mile round trip didn't do further damage to the car (for example it turns out it was suffering from a serious ignition misfire at one point - 800 miles of motorway driving would have melted the cat down) and that it made the trip in one piece with a gearbox that seemed very flaky at the time. A complete and utter waste of time to drive all that way for one or two days, that's why I didn't do it, not because I didn't want any help.

I have not turned down on-line help from the "boffins", however in most cases it has not actually been that helpful in the final evaluation. A good number of the unnecessary parts that were bought were at the suggestion of the boffins, lets recap a few shall we - coil pack - one of the first things I changed as multiple people were absolutely certain it was faulty - made absolutely no difference. MAP sensor - no difference at all, I still have both the original and the new one and they measure and work identically. Coolant temperature sensor - even though the Lexia proved it was working fine I was talked into buying one. I didn't actually fit it until a year later because I was so convinced it wasn't the problem - a couple of weeks ago I fitted it because it was easy to get to during another job and guess what - no difference at all, because it wasn't faulty.

Faulty battery clamps and voltage drop were bandied about by multiple people. Despite me measuring the actual voltage drop to be negligible multiple times I was talked into changing the clamps (eventually I had to because one physically split) and guess what ? NO difference whatsoever. (Although I'm glad the clamps were changed as they were physically failing but NOT causing the symptoms) I could go on.

It's clear that none of the boffins have actually come across this specific problem (or problems) before - the only members of this thread who have first hand experience of it are stevieb and larrypxyz. The reason why most of the boffins have stopped posting in this thread is that they've realised they don't have any more of a clue what the problem is than I do. (And fair enough, because diagnosing something remotely is never easy)

I'm not trying to be ungrateful, some of you have been very helpful, but GUYS, seriously, this is not an easy straight forward problem(s), that much should be obvious by now. I'm not totally incompetent, it is genuinely a very thorny difficult to diagnose problem, so anyone who thinks that they can solve it in one or two days having never seen the car before is talking BS. I can guarantee if I took it into any normal garage (who wasn't a well equipped and experienced driveability specialist or engine tuner) they would throw up their hands in the air and say "not worth repair", which is code for "I can't figure this one out".

Please Mike, just let it go, and un-subscribe. I know there are a small handful of people who are still genuinely interested in finding out what the problem is like I am (if it is ever found before I give up on the car) - it has become something of a "whodunnit" for me and them, which needs to be put to rest. Intellectual curiosity, determination and a sense that I'm hot on the trail again keep me going at the moment. That and the fact that it runs pretty decently most of the time, and that the symptoms are far less dramatic than they once were. It's gone from being un-drivable without changing down a gear to a moderate hesitation under load that comes and goes that many drivers wouldn't even notice or bother about. The only real concern is whether it will pass an emissions test or not.