Nissan Elgrand converted by LPGC May2017

[LPGC]

Converted a lot of these recently, here's the latest, the second one I did this month.

Owner had me decore the rear catalytic convertors and fit an internal bike securing bracket while I was converting this one.

Square filler at the back





engine bay





switch



bike bracket



Simon

[LPGC]

Converted lots and lots more Nissan Elgrands since I converted this one and bought an Elgrand myself.

[Gilbertd]

bought an Elgrand myself.

Which you promptly seized the engine on......

[LPGC]

bought an Elgrand myself.

Which you promptly seized the engine on......

Yes but that wasn't related to LPG. You having to do major engine work on P38s isn't anything to do with LPG either.

As I explained to you on RRpub forum, Elgrands have a common issue of front cats breaking up, debris from the front cats then blogs the rear cats. This happens on Elgrands regardless of whether they're LPG converted and most that have suffered the same fate were not LPG converted. Sticky#1 on the ElgrandOC forum explains the necessity of decoring rear cats. I intended on decoring my Elgrand's cats before I pulled my 26ft caravan on holiday but I ran out of time to work on my own vehicles before I went away. Knew I'd feel the decrease in power if there was a cat problem and felt it going up a hill on the A30 but in busy holiday traffic, no hard shoulder and with the caravan on tow stopping to work on the exhaust isn't much of an option.

I'm just about to decat another Elgrand which will ensure the owner never has the same problem. I converted this one a few weeks ago for an owner from Glasgow but it's a fresh import which the owner hasn't even seen yet. It only got it's UK registration number the other day, the owner sent it's registration plates to me through the post which arrived yesterday, he would have collected it yesterday but arranged to collect it on Sunday as I didn't know if I'd have time to do the decat today... if not today I might only have got around to the decat on Friday.

[Gilbertd]

I never said it was related to LPG and know the full story, I'm just pointing out that you broke it. Did you find out what had caused the problem as blocked cats wouldn't cause an engine to seize. It would get pretty offended and if you managed to keep it running would start spitting bits of exhaust manifold gasket out as the gases tried to find the weakest point to make their escape.

[LPGC]

Haven't even had time to open it's bonnet since getting it back from Cornwall mate.

I wouldn't have thought blocked cats would cause this either but running with blocked cats can lead to other problems.. engine overheat etc. The oil light came on at one point when I was forced to run it up a hill with the caravan on the back. The engine didn't seize at the time, it seized a couple of days later after i'd removed the exhausts (on holiday) and tried driving it to see if it drove better without the exhausts on, it didn't pull/drive any better and seized shortly afterwards. Several owners on Elgrand club have reported a similar chain of events (but not including pulling a caravan) leading to their engine seizing too (and hardly any of those were LPG'd).

As soon as it broke I immediately txted and phoned people in the Elgrand club about this and told them I'd be writing a full report on it but I haven't got around to doing that yet. You can imagine how long one of my 'reports' will be on something like this that lots of my customers will be interested in but I've been too busy.

Edit: Write up https://forum.elgrandoc.uk/threads/the- ... 443/page-9

[rich r]

We've had a couple of instances in the UK Subaru Legacy Owner's Club of aftermarket front cats breaking up and the contents being sucked back into the cylinders on the 3.0 flat six engines - damaging the exhaust valves and ultimately trashing the bores and head surfaces. Luckily it's so rare that nobody's really worked out why it happened, and in each case the cat manufacturer has paid out for an engine rebuild or replacement. Now that's an unexpected way for cat failure to seize an engine

I think I posted enough on here about the odd behaviour of my wife's LPG Honda CRV that did in the end turn out to be a blocked cat (but looked for all the world like a timing or fueling issue).

[LPGC]

Thanks for that Rich.

When the front cats on Elgrands go it seems it doesn't usually lead to problems with the engine IF the rear cats have been decored, but if the rear cats are still in place they get blocked by the debris from the front cats... And I suppose it is under these conditions that debris from the front cats more often makes it's way back up the near vertical and longish manifold to front cat pipes. If the engine hadn't since seized completely I would have expected to find just (hardly 'just' really lol) scored valves, pistons, bores but because it's since seized the scoring has probably lead to some sort of mechanical jamming (such as valve stuck open for piston to wallop).