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[ChrisS]

Well, having only recently got the GC, it's booked in for it's LPG conversion next week.

...so, I thinks...wonder if it had new plugs at the last service - not due, but you never know, and I think new plugs would be a good idea on a gas conversion. So, read the manual. It says remove the strut top brace, remove the plastic engine cover, remove the coils....

First look suggests that the strut brace has never been off. Undo the nuts.....and then find out why it's never been off. On a RHD model, the brake master fouls the brace and stops it lifting off the stud that side, and the other side, there's a great big chunk of loom preventing the brace from coming off there as well....so I resorted to the same technique that the dealers probably used....just 'persuade' the plastic cover to come out the gap between brace and engine. Probably explain why the cover has got two great big cracks in it.

Turns out the plugs are in good order, but not new and have likely done about 20k miles if they've ben done according to schedule, so I'll put a fresh set in anyway. Can't hurt. Probably fit a new air filter as well but will see what it's like first - no point in swapping it for the fun.

I wonder which other procedures don't work on a RHD version........


Still, nothing nasty found under the cover so far.....

[Bubba]

on what engine ?

[ChrisS]

on what engine ?

Bloody good question!

Sorry - an 07 model year 5.7 Hemi (the one with the coil per cylinder rather than coils & HT wires).

Been assured it doesn't have issues with valve recession but happy to hear from anyone who knows any different. I can't imagine why the installers wouldn't want to fit the Valvecare option if it was needed.  I can see an unscrupulous installer saying you need it when you don't, as it's more money for them of course.

[ChrisS]

Well, 8 plugs done, 8 to go.

The RH bank back ones are a bit of a fiddle......

[JamesH]

It's a good idea to the whole ignition system in top condition for an LPG converted vehicle so changing the plugs is a good job to do.

Out of interest, do you know if the multi-displacement system (where it shuts off 4 cylinders for economy) still works the same with an LPG conversion as it does on petrol?

[ChrisS]

It's a good idea to the whole ignition system in top condition for an LPG converted vehicle so changing the plugs is a good job to do.

Out of interest, do you know if the multi-displacement system (where it shuts off 4 cylinders for economy) still works the same with an LPG conversion as it does on petrol?

I reckoned it was a smart thing to do based on what I'd read so far - thanks for the confirmation. The old plugs look in perfect condition so far, which is always a nice thing to find. Can't hurt anyway, and even after swapping 8, I can convince myself it's already slightly smoother at idle. Probably just deluded though  

I did ask about the MDS and was told that as the LPG system is designed, it works the same with MDS/LPG as MDS/petrol. It reads the petrol injector pulses to generate the LPG pulses...so no injector pulse from the main ECU, no LPG for that cylinder. Sounds plausible anyway.  Being the nosy and curious type that I am, I might just have a poke about with a 'scope when I get it back. I did also read somewhere that there is a specific Prins version for the MDS Hemi..can't recall where though.

Re the MDS, I was wondering about fitting an indicator lamp to see when MDS is active. Might get round to it after the LPG conversion....but then again, might not as it's pretty academic. Can't help being curious though.

[ChrisS]

Well, nearly finished. Had a bit of drama with one of the other cars yesterday so didn't get a chance.  Just got 2 more to do now.  I checked the air filter while I was at it...and that needed changing. Clearly, the 'service' it had at the used car dealer wasn't exactly thorough. To be fair, it wasn't due so I guess they just did it as a seliing point, but not doing it properly is worse than not doing it at all IMO.  To cap it off, I think they put the wrong oil in it as I've got a recurring P1521 code so there's a good cahnce the MDS won't be behaving as it should.

Bloody cowboys.

[ChrisS]

Finally finished the plugs - all good apart from one cylinder has a small oil leak from the rocker cover into the plug wells. Cock.  Looks like it's from new TBH - no sign of tamperage anywhere. It'll be OK for now - it's not coming out the top, just very slowly building up in the wells.  I'll sort out a new gasket and get it done soon. Shame I couldn't have done it before it went on for conversion really, as there will be a bit more stuff in the way by the time I get it back.

Got the chance to change the oil yesterday before it went in for the LPG conversion. Cleared the P1521 code, then did the 40 odd miles to the converters...and no new code. Previously, got a new code the first few miles after clearing down.  I can also convince myself it's smoother as well - before the change it gave the odd lurch under conditions that would probably mean it was swapping from 8 to 4 or vice-versa. A known symptom of the wrong oil.

So, suspicion confirmed I think. Muppets.

I like the 'chute' under the oil filter. What a good idea. It might not catch every drop...but at least they tried. My Alfa's are complete bastards for getting oil everywhere on a filter change. Horizontal filter on the back of the block, barely accessible at the best of times, and they p155 oil all over the place when you spin them off. Damn stuff drips for days afterwards.

And the convenient hole in the undertray so you can get at the sump drain.

I'm liking this Jeep more and more. Going to miss it while it's away