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

[addo]

By what mechanism can it achieve miracles? Have Lubegard tested their water dispersant spray on the Red Sea?

You can help the motor by idling for just a few minutes prior to driving off. Loading it up when stone cold is one way to increase the combustion waste in your oil. Only have to wait until the temperature gauge is on the lowest notch. By then I usually find the mirrors and rear glass are starting to clear.

[Chris570]

I'm with addo's cynicism here. I would get that old oil out pretty quickly, especially if you think that the noisy valve gear is causing the problem. Yes it has an additive in it but you'll get cleaner having a bath in clean water than you will in sewage mixed with shampoo. Do your engine a favour and get the gunk out.

Is the battery clamp done yet?

[addo]

Some good mental imagery there.

[Chris570]

Some good mental imagery there.

the language was going to be colourful but i decided against it

[addo]

Once you're a doting father, you'll discover how unfazed you become by #2 turning up in the bath...

[Chris570]

perhaps not but i've have the good sense to remove the crap from the area i wish to be clean

[addo]

It's every man's right to have a properly running motor if he wants it.

[Chris570]

In the same way it's every mans right to have a baby?

Or is that only in Judea?

[Mandrake]

By what mechanism can it achieve miracles? Have Lubegard tested their water dispersant spray on the Red Sea?

Healthy scepticism is good guys, but so is an open mind and thinking outside the box.

We're not talking about a run of the mill easy to diagnose and fix problem here as the length of the thread shows, I think many of you would have been tearing your hair out in the same situation and probably have given up long ago...

There have been other faults too... faulty plug leads for sure, at one point I had fouled plugs, and my new coil pack went and failed on me last month. I'm just talking about the remaining symptoms after those have been resolved, eg the ongoing intermittent hesitation, throttle lag and low power at low rpm.

What could it do ? How about removal of varnish and sludge ? The fact that the tappets are silent on start up now should make it obvious that it has done something. Will it last ? I don't know. If it does last what has it done exactly ? No way to be sure. I'm not a chemical engineer...

You can help the motor by idling for just a few minutes prior to driving off. Loading it up when stone cold is one way to increase the combustion waste in your oil. Only have to wait until the temperature gauge is on the lowest notch. By then I usually find the mirrors and rear glass are starting to clear.

I always used to let my Citroen's idle for at least 30 seconds before driving to let the suspension lift, I've been a bit lazy with that lately so I really should go back to that...its good for the engine if nothing else. In the winter it usually gets to idle 5 to 10 minutes while the heater warms up and the ice is scraped off the windows...

I'm with addo's cynicism here. I would get that old oil out pretty quickly, especially if you think that the noisy valve gear is causing the problem. Yes it has an additive in it but you'll get cleaner having a bath in clean water than you will in sewage mixed with shampoo. Do your engine a favour and get the gunk out.

It's not "old" oil, its only been in there a month... The additive that's in there now has some varnish/sludge removing agents in it (although not as much as their specific flushing agent) so some of that crud will be coming out into suspension in the oil now. I'll give it another change next month, no money left this month for stuff like that.

Is the battery clamp done yet?

Nope. I have one of those quick release clamps that RichardW suggested, it looks like a better fit than the other one but I'm still sceptical of its long term durability and whether it will be any better than what I have now. The clamp is clamping nice and firmly since I straightened it out and there are no problems with voltage drop, so no evidence that it's causing any issues. I'm trying to avoid "diagnose by replacing" which I've done far too much of, and actually replace stuff that tests faulty...

[addo]

The battery clamp is more your metaphorical preemptive mastectomy.

[addo]

I'm not saying the additive has done nothing, but its addition also corresponded - did it not - with a measurable rise in ambient temperature?

[Northern_Mike]

I don't think it's that simple.

Neither do I . AIUI, knock sensors detect a specific kind of sound. My extensive experience of tuning old Saab Turbo engines (which use a knock sensor to wind the boost down) leads me to believe this. I do not believe, from experience, that tappet noise will trigger a knock sensor. Neither will knackered small end, big end, or main bearings, or timing chains rattling against tensioners.

Sent from my GT-I9300 using Tapatalk 2

[Chris570]

my "old" oil comment was in reference to the black oil that you drained out to put the additive in. its gone very dirty very quickly before the "cleaner" went in. That suggests very dirty engine.....

My method of sorting problems where there is no obvious fix is to correct everything that you find as being wrong, usually that will fix it but if it doesnt you'll at least be able to rule a load of stuff out. Getting the engine oil clean is not an expensive task and with the greatest respect (genuinely not trying to be harsh here) if an oil change is too expensive maybe an HDi would be a better bet. As you've just said, this isnt an easy fix, so you've got to decide which way you want to go with it.

[addo]

I've personally seen three or four engines where the worn timing chain has chewed through the timing case or rocker cover. All ran fine enough, and at least two were equal "age" of technology to the subject engine.

One could sample the sound of a known good knock sensor, loop it and send that into the ECU as a dummy signal... I would put quids on the problem still being there.

[Northern_Mike]

I've personally seen three or four engines where the worn timing chain has chewed through the timing case or rocker cover.

I used an old Saab with T16 motor for testing various engine mods before I applied them to the car I actually used them on my "nice" car. By the time I finished with it, it knocked, rattled, the timing chain was stretched and whipping and the gearbox under the engine vibrated.

Didn't bother the knock sensor though. Still showed 241bhp on the rollers.

If Simon's problem is knock sensor related, I'll eat one of my 39 hats.


Sent from my GT-I9300 using Tapatalk 2