My engine is seized now because my cats blogged the exhaust while I was towing my caravan going on holiday.
A few people from forum already know about it happening to me too, as I spoke to them on the phone while on holiday.
I told them I'd write a full report about it on this forum at some point after my return from holiday, I've been back from holiday a few weeks now but during those weeks I've been very busy (converting Elgrands and other vehicles), helping to rescue LPGforum, helping someone move house, and I had to go back (to Cornwall) to collect my caravan.... So I haven't had much time to write the sort of lengthy detailed post that people have to come expect from me (even on lesser matters) on this important matter.
But it's about time I wrote something even if it's not as lengthy or detailed as I intended.
The gist of it is that I didn't have time to decore my own Elgrand's cats before I went on holiday to Cornwall fully loaded with people and with my 26ft Caravan on tow also fully loaded. Towing uphill on the A30 up Bodmin Moor I felt a sudden decrease in engine power (as I've said on this thread before people should expect to feel when their cats go) and recognised that this was probably due to the cats having failed, so I pulled into the first layby and scanned the vehicle OBD for engine problem codes. There were error OBD problem codes for camshaft position sensors, this confused the matter because cam sensor issues could also mean lower engine power, so I phoned a certain guru on this site for a second opinion before taking the exhaust off (which would have meant sending someone who was following us in another car with a baby on board into the nearest town to buy the necessary tools). Guru reckoned it unlikely to be the cats that were the problem, I should try cleaning the cam sensors and see how it drove/towed then. So perhaps against my own judgement I did continue on the journey to see how it went after cleaning cam sensors but after cleaning the cam sensors the engine was still down on power. Now that I'd connected my laptop to get more detailed information (from the LPG system readings) than any code reader could provide (at least regards fuelling) I could see that the problem was on the passenger side bank of engine cylinders. So, I didn't drive much further (just a couple of miles but with the engine struggling) before pulling into the nearest layby and phoning the RAC. RAC man number 1 came out, I told him about the problem with Elgrand cats and that it seemed very likely to me that this was the problem. He listened but even though he couldn't find any problem himself (and his OBD scanner gear didn't even work on the Elgrand whereas I'd got a £30 JOBD scanner on board that did work on the Elgrand which told me about the cam sensor issue, which I told him about), he didn't seem to believe it would be cats that were the problem and seemed to be in a rush to get away. He told me that my RAC cover on;y covered the car, not the caravan, and that if I wanted the caravan shifting to Newquay from here (30 miles away) it would cost me about £500 by one of their sub-contractors. He recommended I continue to drive 'now the engine has cooled down a bit' and told me 'we are right on the top of Bodmin Moor here so its all downhill to Newquay' and 'see how it goes on the downhill stretch you should be OK to Newquay from here'. This time, very much against my better judgement and I have to question myself on why I did it... I drove a few more miles towing the caravan and it felt the same but getting worse. RAC man number 1 was still following me at this point so I pulled over half onto the grass verge and RAC man stopped behind me. At this point I insisted he loaned me a hammer and chisel so that I could knock a hole in my exhaust because he wasn't allowed to do anything like that due to Elf-n-safety. I even had to sign a disclaimer form before he'd loan me the hammer and chisel and then another form to say I'd decided to do something against his advice. I knocked a hole in the exhaust just in front of the passenger side rear cat and loads of cat material that must have come from the front cats breaking up came out, so I had to knock a second hole in it much further up the pipe closer to the front cat just to make the hole in front of the broken cat material that was clogging the rear cat and it's feed pipe. RAC man was very surprised to see the cat material come out of the hole and, really, at this point we both knew that him advising me to drive further might have caused me some severe problems and that I was daft to have followed his advice... This time starting the engine after knocking the holes in the exhaust I could see on my laptop readings that the engine seemed much happier, was drawing more vacuum and it revved more freely... But the exhaust was now rather loud with the holes I'd knocked it it! We all set off again and this time the engine pulled properly just as it did before the problems had started. I thought problem nearly solved I'll just get an exhaust place in Newquay to decat and fix the holes in the exhaust while we're on holiday. RAC man who was following phoned me and said 'You seem to be OK now so I'll leave you to it'. I said 'OK mate cheers'. But 10 miles further down the road and after the RAC man had left me the same lack of power problem re-occurred and seemed worse than ever. This time it couldn't be a problem with the passenger side cat, if it were a cat problem it could only be with the drivers side cats (which I hadn't knocked a hole in). At this point my laptop battery had died so I didn't have the diagnostic window that the LPG software had given me earlier. And this time the engine started to overheat and then the oil warning light came on while I was going up another steep hill (after the RAC man had said it was all downhill to Newquay 10 miles earlier). I pulled over again in as safe a spot I could manage/make it to (but still dangerous especially with the volume of traffic) and called RAC out again. RAC man number 2 came out, he had an outline description of what had happened before from the RAC but I filled him in with the details. Told him I wanted the car and caravan shifting to Newquay but there was no way I was paying an RAC subcontractor £500 to shift the caravan, said he must know some recovery garages in the area please phone them instead of the £500 RAC subcons. He phoned a recovery garage for me, they didn't have a lorry big enough to put the caravan on but came out with a lorry and a van, the van pulled the caravan, the Elgrand was loaded onto the lorry.. These were good lads and I'd use them again if I needed a tow in Cornwall. £150+Vat for shifting a car and caravan 15 miles using two of their vehicles and 2 guys so a reasonable price too. Arrived at camp site 5 hours later than expected, a bit tired, no working car and a broken Elgrand. Got set up on the campsite and next day while everyone else went into Newquay I set about trying to diagnose and fix the Elgrand. I went to St Austell in the other car that went on holiday with us and bought loads of tools, engine oil, etc, and then unbolted the other side exhaust (drivers side the side I hadn't knocked holes in). I hoped the more recent problems (after the apparent fix) would be fixed when I removed the drivers side exhaust but the engine still pulled the same. Going out of the campsite there's a very steep hill at each side, I started going up a hill and the engine suddenly seized dead. I rolled backwards down the hill all the way back into to the car park of the camp site which is where the Elgrand stayed until I more recently went back to Cornwall (in my Merc ML) to get the Elgrand shifted back home. But at least I got a couple more days in Cornwall out of the misfortune lol!
When I have this engine out I'll strip it to see what damage the cat problem led to. Would be interesting to hear/read if other people have stripped engines that failed following cat problems and what damage they found... Perhaps this engine could be repaired (I won't know until I've stripped it) but I'm thinking it'll probably be just as easy just to get another engine for it.