Fastback's cars.

[scoobyh123]

I sense your fears Mark, before you dive in with the spanners etc, try adding 0.5L of Carlube ATF-U or NAPA MVA to the engine oil. Will take 2-300 miles minimum before you notice any improvement but i suspect you have dry valve stem seals and dirty hydraulic tappets. Are the tappets a bit ticky when cold?

[Fastback]

Don't believe the tappets are sticky; sounds okay, starts okay, revs okay (gentle dabs when testing cold). But I can detect a slight uneveness sometimes on tickover (warm or cold) that suggests one cylinder isn't firing properly. Or have I misread that?

[scoobyh123]

I don't think you've misread anything Mark, you have provided an additional clue to the tappets not being quite right though. I'd definitely give the ATF trick a whirl before getting into the expense and time of stripping and rebuilding the engine.

When i got my Sterling the emissions were ~0.1%CO and ~300ppm HC at the MoT, last MoT was 0.00% CO and 86ppmHC - when i do an oil/filter change, after refitting the sump plug, the first 0.5L of oil is Carlube ATF-U topped off by a decent 10W40 semi-synth. It no longer suffers from the post-cold start tap-tap-tap the C27 is infamous for, starts silently and rem,ains silent until it gets near oil/filter change time.

Performance and economy are both up and emissions are down. Even on my Volvo that has solid tappets it makes it quieter and the HC has dropped in the time i've owned it. On my Jeep Cherokee, when i first got it, it sounded like 3 pile drivers were in the engine on a cold start and still ticky when hot because of three dodgy tappets.
Oil/filter change, 1L of ATF-U followed by 6L of 10W40 Tradetec (now NAPA) semi-synth and under 1000 miles later it started silently (apart from normal engine noises) from cold and never made any untoward noises at all. Performance and economy went up too, usually managed 24mpg on LPG surprisingly!

The ATF helps free piston rings (which restores compression) and free up sticky hydraulic tappets, even those that dont' sound bad. It also helps condition/revive the various rubber oil seals in the engine so reduces (and in the Jeeps case which had a rubber rocker cover gasket, eliminates) oil leaks.

For the cost of 1L of synthetic ATF, i'd say it is well worth trying!

https://www.ebay.co.uk/itm/175373228020

If i ever own a KV6 powered beast (tentatively looking for a 75 Tourer to replace the Volvo) i'll definitely be adding the ATF at every oil/filter change and probably before the drive home too.

[Fastback]

Thanks, Dave. I'll certainly put some in and see what happens. I'm not enamoured at the thought of a rebuild but would/will do it and for the parts, about £700, 'happy' to spend that.

I'd rather do it before the engine 'lets go' as I'm sure that would be better all round. So, in preparation for a rebuild scenario, what is the thinking for the liner height and gasket type as I believe 'proud' is right but the difference between 0.05 and 0.3 seems a lot?

[scoobyh123]

I get what you're saying Mark i'll try and check on the liner height but having trouble accessing RAVE at the moment due to the fact my PC doesn't have an optical drive - so called progress!

If my guess is correct that it's only sticky tappets and dry valve stem seals then the ATF should sort it out. You may also have sticky piston rings too and again, the ATF should sort that out too.

[Fastback]

my PC doesn't have an optical drive - so called progress!

I'm a bit of an 'oddball' when it comes to things like this. I have multiple optical drives including Bluray burners and still have a PVR (hard drive TV recorder with BluRay player) attached to my TV. How quickly the cutting edge technology is usurped. I even have an external 3.5" magnetic drive I can connect via USB.

Of course you can buy external DVD drives the same and they're not massively expensive any more, from about £20! Probably well worth it to regain such a useful resource.

[scoobyh123]

Oops, double-post! How did that happen???

[scoobyh123]

my PC doesn't have an optical drive - so called progress!

I'm a bit of an 'oddball' when it comes to things like this. I have multiple optical drives including Bluray burners and still have a PVR (hard drive TV recorder with BluRay player) attached to my TV. How quickly the cutting edge technology is usurped. I even have an external 3.5" magnetic drive I can connect via USB.

Of course you can buy external DVD drives the same and they're not massively expensive any more, from about £20! Probably well worth it to regain such a useful resource.

I have a couple of old latops (one is Win XP!!! ) with optical drives but the newer one has trouble reading the RAVE disc. The XP is too slow to do anything with except tuning LPG systems and looking up tuning data, the main reasons i bought it. I think i'll have to invest in an external optical drive, not sure if i have enough USB sockets on this PC, one has the dongle for the keyboard/mouse in and the other has the Jag USB WSM in - arguably that could come out while using the RAVE disc. Might be a couple more USB sockets but i'd have to check.

The big problem is exactly as you say though, technology is changing on a daily basis and by the time we see the latest tech in the shops, it's already been outdated 6-7 times just because of the lead-time from launch to manufacture for the masses etc.
The subject of RS came up on another forum recently and it reminded me i have an RS branded gas powered soldering iron and my dominant memory of using that is on the monkey island of a dredging ship in a Force 5 gale to solder a plug onto the end of a GPS aerial lead in 1998. Looking at the rest of the system they were using, it gave me the idea for sat-nav as we now know it but their system had been in use for some 10+ years at the time.

About 3-4 years later (~2001/2002) the first Tom-Tom Go was launched so bang went my brilliant idea for getting rich!

I also remember vaguely when the Mini-Disc system came out and that was meant to be the new CD but was comparatively short-lived, ousted by the mp3 file and smartphones that had BlueTooth and BT enabled car stereos.

These days i take a more pragmatic view of things and wait to see firstly if the new tech is going to stay around and then deicde if i can actually use it before buying anything.

[Fastback]

I have just been prompted into thinking, have I overlooked the obvious ? We are all so keen to knock and even despise the KV6 engine (which actually is good, yes , I just said that) and equate a slight engine uneveness to catostrophic failure! I've had the Sterling ten years and 40,000 miles now and barely spent a penny on the engine. I've checked through my receipts and can't even find one for a set of spark plugs!

Now I reckon it's worth replacing them, before rebuilding the engine. Rough idle, lack of power/acceleration and poor higher speed cruising are surely symptomatic of a worn plug(s)? I believe platinum was specified as standard, anybody got any feelings about an alternative? Anybody else run a KV6 here?

I haven't added the ATF-U yet because it hasn't flippin' arrived.

[scoobyh123]

I have just been prompted into thinking, have I overlooked the obvious ? We are all so keen to knock and even despise the KV6 engine (which actually is good, yes , I just said that) and equate a slight engine uneveness to catostrophic failure! I've had the Sterling ten years and 40,000 miles now and barely spent a penny on the engine. I've checked through my receipts and can't even find one for a set of spark plugs!

Now I reckon it's worth replacing them, before rebuilding the engine. Rough idle, lack of power/acceleration and poor higher speed cruising are surely symptomatic of a worn plug(s)? I believe platinum was specified as standard, anybody got any feelings about an alternative? Anybody else run a KV6 here?

I haven't added the ATF-U yet because it hasn't flippin' arrived.

Ah, we overlooked the KISS principle, i sort of assumed you had renewed the plugs as and when needed so didn't mention them but had to renew the plugs on my Volvo recently for a similar reason. They'd been in for about 18k miles though so had a right to be not quite right. Those are just basic plugs though, no fancy precious metal electrodes to prolng their lives either!
I always thought the KV6 ran on Iridium plugs but could be wrong, i know my Jag uses Iridium and the change interval is 100k miles!
The big problem with precious metal plugs, beside the obvious cost penalty, is the fact they stay in the heads for so much longer, usually without being checked. That can often cause problems removing them too.
There is now a school of thought that says NOT to use anti-sieze compound such as graphite or copper grease to prevent the plugs locking with corrosion/heat in the head as the theory is, they can be over-tightened as a result. This (apparently) means when you come to undo them the threads will have tightened as the lube has moved/dried etc.
Not sure i agree with the theory as experience has always taught me it's better to use some copper grease than not, both with spark plugs and also Lambda sensors. Also exhaust manifold and downpipe nuts to name but a few places i've used it successfully.

As you know, i don't run a KV6 but i am looking for a replacement in the near(ish) future for my Volvo, so far the favourites are a Honda CR-V, early Volvo V70 or a Rover 75 Tourer with the KV6 as it's about the best engine in the Rover 75. With that in mind i might be getting more intimate with the KV6 (although in modified form) in a 75 in the future.

Still not sorted either of my laptops that have optical drives (or found the RAVE CD although i think i know where it is) but haven't forgotten, ditto on the scuttle panel.

[Fastback]

Even I fell into the trap of the doom spiral. Never gave plugs a thought, can't really believe I've not replaced them at some point.

Just bought some NGK BKR6EIX 6418 Iridium plugs. I'll fit those and maybe even add some ATF-U, if it ever turns up.

I shall report back in due course.

[scoobyh123]

Sometimes we all have to take a step backwards and take a fresh look at things and go from first principes Mark, nothing to be ashamed of.

Been fighting a problem on my Volvo for a while now, severe over-fueling when cold. Usually its the CTS so renewed that. No improvement, if anything, it was worse but that might have been subjective as i was expecting an improvement and no change happened.
It has had new plugs, a second new set of leads, marginal if any improvement from that. Then i remembered the oil pressure warning light hasn't worked when cold for a few years but always works when warm. Conclusion, the soya bean insulation on the wiring has gone solid and when the copper wires have cooled and shrunk, the insulation hasn't so the wire has broken through no fault of its own. The over-fueling first happened after renewing the 'stat and i moved the plug and wiring out of the way of the 'stat housing :



CTS ringed in red

You can probably guess i haven't done much about it yet but as the engine warms up, the fault disappears except sometimes it will give the odd hiccup. At some point i'll need to trace the wiring back to where it's good and fit a new EV1 plug and wiring. Just another case of overlooking the obvious.

[Fastback]

On possibly the first truely nice day of the year, I've had some fun and games changing the spark plugs on the Sterling (KV6). It was not without its problems and what you're thinking is probably wrong. The main difficulty I had was this,



These are some plastic bits from the top of the ignition leads that sit inside the plug chamber. Unfortunately some of those pieces fell to the bottom which prevented me from putting the socket over the plug. It was several of the small shards on plug 4 (rear bank, of course) which gave issue. After much fiddling, managed to get them out using bent metal wiper blade inserts and Blu-Tack.

Other than that, no real problems. Don't fully understand why people think it is difficult; yes access is a little restricted but if you build up your socket, extensions and knuckle, rather than trying to stick it all in at once, it's fine. No dropping the engine and just working round the bar. If I can do it, seriously, anybody can. I suppose it's a bit like the weather thing; to paraphrase, 'there's no difficult job, just the wrong tools'.

It looks like I have changed the plugs in the past, just not made a note of when as the plugs I took out were NGK R twin cathode. Would anybody like to comment on them?



The ATF-U finally arrived today so there is now about 400-500ml in the system. Let's see how that goes.

[scoobyh123]

There's only one of those that i'd consider halfway serviceable Mark, bottom row, #2/centre. Tope row, #3/extreme right looks glazed suggesting running lean, misfiring, possibly burning oil due to lack of petrol. The others are all showing signs of being well used and all have a fair amount of spark erosion on the centre electrode.

Standard plugs are BKR6E on the KV6 according to the NGK Partfinder, a single earth electrode jobby.

Wouldn't mind betting it runs a bit smoother now!

Might also be an idea to drop a couple of eggcups of ATF into the petrol tank to help clean the injectors (will also help prevent the tank rusting inside), let us know how it goes on the new plugs!

[Fastback]

Most I think are suffering from oil vapour in the cylinders, which means the seals are a bit iffy. Hopefully the ATF-U will help. Are you aware of Forte seal conditioner and does it do anything different to the ATF? Top right is plug 3, the chamber was flooded with oil, gasket leak.

I have replaced with NGK BRK6 EIX, which are Iridium. Not driven it yet, so I dont know how it accelerates and drives at higher speeds. I will report back.