If you're running on LPG and the diaphragm in the reducer is starting to perish, LPG can seep through into the coolant passage in the reducer. That will give a positive reading for hydrocarbons in the cooling system. It's not common but has caused quite a few people to strip their engines down unnecessarily.

Seems I owe Sloth a pint for being spot on. Went outside this morning to get to the bottom of this and found the problem. Got another one now but I'll get on to that in a minute.

Crawled underneath to look at the wiring and plug on the RH bank lambda sensor(s) and couldn't see anything wrong (for some reason I was convinced it was the RH bank one that was causing the problem). Looked across at the LH bank and noticed that the cable was very close to the exhaust downpipe. The outer sheath had a hole in it but the insulation on the wires wasn't touched. However, while moving it around to see why it was dangling against the exhaust I noticed it was also very close to the propshaft. When I'd looked before it had been from above and I could see the sensor and propshaft but the cable then just went towards the front of the car to the plug clipped to the side of the sump. At the front it had been just, only just, rubbed by the propshaft to the point where the insulation on the red (12V heater) wire had rubbed through. When going forwards the rotation of the prop had pushed it away from the prop but when in reverse.....

So, having taped up the dodgy bits, I re-ran the cable behind the transmission cooler pipes so it wasn't anywhere near the exhaust or propshaft, I decided to check that everything was working as it should. Rather than use the Nanocom, I plugged in my Launch C Reader as it can display live data as a graph with different coloured traces for different things. Started it up on petrol (as it now runs properly on petrol since I cleared the clogged injector) and at idle the lambda sensors were switching from 5 to 0V just as they should (although the C Reader displays it as 1 to 0V as that is what the OBD spec calls for). Drove off down the road and still switching. Stopped at a shop, switched off. I had intended checking that all was fine on petrol before switching to LPG to make sure it was holding the fuel trims correct. As the single point LPG system uses it's own separate lambda sensor, if there is any resistance in the feed, the controller will set the mixture slightly rich. So I wanted to make sure that the fuel trims stayed the same and the lambdas were still switching when on LPG too.

A couple of minutes later, got back in, restarted (still on petrol), rebooted the C Reader (as it disconnects as soon as the ignition is switched off) and both sensors were flatlined at 1V. Ran it for a mile or so in case they were still cold and still it showed a flatline on both. Unplugged the C Reader and plugged in the Nanocom. It showed bank 2 as running closed loop but the lambda sensor was only switching from 5.0V to about 4.6V while bank 1 showed OPEN FAULT with no switching at all. So why would it be switching perfectly until I switched it off for a couple of minutes and then not switching and showing a fault on one bank when restarted? Switching it off and restarting again and still the same. No fault codes have been logged either, weird. Sloth, what's your verdict this time?

I think I see what you are getting at. Using a 5 pin relay so with dip and the fogs on the feed to the fogs would be via the normally closed contact in the relay so would work as normal. When you switch to main beam, the relay would operate so the fogs would come on as auxiliary lights. It shouldn't cause a problem though because normally as soon as you switch to main beam, the supply to the fogs is cut so there would be no current to monitor anyway. You're right on the law. Dipped beam headlights must be no greater than a total of 110W (or the equivalent if the car has HIDs), front fogs may only be used with dipped beam as the theory is that if the fog is light enough that you can use main beam without blinding yourself with the glare, you don't need fog lights. But main beam is as much light as you can chuck out of the front as you like. There's no restrictions on number of lights or total Wattage.

Maybe turning off the bulb monitoring is another of those odd things that the Police spec setting in the BeCM does so they can wire the front fogs to flash along with all the other lights. It's never really bothered me to be honest, I've spent most of my life having to look at the reflection of my lights on the garage door or the back of another car to see if all the bulbs are working, that the monitoring is just a bonus (or, in the case of a dodgy front sidelight bulb holder, a pain in the arse, all that beeping to tell me a light I would never use on it's own isn't working).

Orangebean wrote:

Gilbertd's is an ex Police vehicle IIRC so might have a different wiring fit.

Not sure if it's that different, I've taken most of the spurious extra cabling I found in it out. It's got a high line BeCM and no extra relays for the front fogs that I know of. Unless there's some extra wiring I haven't found yet so they could flash the front fogs along with the blues and twos.

That's a new one, on a GEMS, the wires break off where they come out of the plug so you get open circuit and the temp sensors think it's -40!

Current state of things is that the LPG controller is using the additional sensor so everything back to as it was. Just went outside to turn the car around. Reversed out of the driveway, no problem, pulled forward, no problem, left it running while I put another car on the driveway, no problem, went to reverse into the driveway, moved about a foot and the fuse blew. Fitted new fuse, restarted the engine and reversed into the driveway. Definitely looks like I need to get under it to look at the wiring for the bank 2 lambda sensor but as it's raining again (and I'm supposed to be working from home), that'll have to wait.

May be getting somewhere here. Decided to sort out the running on petrol at the weekend so pulled the injectors out. Squirted carb cleaner into each one, blew through it and applied volts to it and got a nice stream coming out of each one except for the one from number 5 which did nothing. It clicked with volts on it but I couldn't blow through it (got a gobful of ether though). Tried various different solvents and an air compressor and still no flow so fitted the other 7 injectors to the fuel rail and attached it to the fuel rail upside down. Ignition on to pressurise the rail, applied volts and it squirted fuel out, a lot of fuel, all over the engine. Pulled it out of the rail and even more fuel squirted all over the engine. Tried blowing through it again and this time it worked. So put everything back together.

Reset the adaptive values and started the engine on petrol and for the first time in over a year and a half, it ran on all 8. Reversed out of the driveway and bloody fuse 26 blew! So, it's still blowing on petrol and the LPG controller was disconnected from the lambda sensor at that time too. Ran it down the road on petrol with the Nanocom connected and bank 2 lambda sensor was showing a constant 5V whereas bank 1 was switching as you'd expect. Connected the LPG system to the additional lambda sensor in the bank 2 downpipe, changed over to LPG and it was switching. So was the bank 1 sensor but bank 2 sensor stayed at 5V all the time. So it looks like a problem with the bank 2 sensor, maybe a short between the heater and signal (I suspect that as the Nanocom and the LPG controller are expecting to see a 5-0V signal they will both display 5v if they see anything greater that that). An internal short (or a problem on the wiring) would explain the blowing fuse but not why it only does it when going backwards and not why it doesn't just blow. Further investigation required still but I think I'm getting somewhere.......

Probably from a mosfet but they don't have bulb monitoring. One of mine fills up with water so the bulb blows regularly but the dash never tells me, I have to use the traditional method of getting out and having a look.

You can give it a go, nothing to lose and if it works, job done..

I found that a socket intended for the smaller sized spark plugs is a good fit on the head bolts and 6 sided too. For some reason I'd got two of those in my toolbox, a 3/8 drive and a 1/2 inch. The 1/2 inch drive one with a short 3" extension, means I'm not using anything 3/8 drive. Mind you, it could be worse. Ex used to have a Porsche 944 and to change the rear brake shoes meant taking the rear driveshaft nut off. Only problem is that it is a 36mm nut done up to something like 260 lbf/ft. The only way of shifting one of those is with a 3/4 drive impact socket and a 10 foot scaffold pole......

Looks like you've had both in there. K-Seal leaves a residue of copper powder while Steel Seal leaves white stains on everything. Both claim to not clog things up but that isn't what I've found.

Good luck with resealing the rad, I've always thought that once apart they'll never go back together properly again so haven't even attempted it.

I use the handle from my trolley jack slipped over the 1/2 inch ratchet handle so I've got about 5 feet to swing on. I've used a 3/8 socket and found that Halfords will honour the lifetime warranty on their Professional range of sockets when you shear the 3/8 to 1/2 adapter off.......

Oooh, I can moderate and edit other peoples posts!!! Changed it so the pictures appear in the post and not just the URL for the pictures.

From those pictures, it all looks no worse than I would expect to see. You had combustion gases in the coolant so they had to be getting in somewhere.

Upload photos to Photobucket or similar, click the insert image and then put the url for the image in the pop up box.

The Yanks seem to love them (but they are a nation of bodging buggers) but with all those extra connectors it's more likely if you didn't have a leak before you fitted it, you will afterwards. So it gives you the ability to bypass your way round a problem it created in the first place.........

Don't poke at all, get underneath and give them a squeeze. You'll know when they are clear as you'll get a stream of water, mud, leaves and other assorted debris run down your arm.

I don't think it will cause any faults as such, it just won't retard the timing if it does start knocking so could do damage to the engine.

Yes, as long as the sump is off so all the crap gets washed out the bottom.

If it was mine, I'd drop the sump off so you can clean that out (and the oil pickup strainer) and wash everything off with diesel and a paintbrush. I used to use paraffin but diesel is cheaper, does much the same job and gives it a second use after lighting bonfires.

1/4 drive 8mm socket and a short ratchet may work on the bolts on the heatshield, either that or a Dremel to cut the heads off. If the rockers are all black and sticky, it's been pretty well neglected in the past and you'll probably find the rest of the engine internals the same.