Misfire on startup, clears < 1min.

Okay so I've fixed all the MoT Test failures.

Misfire on startup, clears < 1min. I am losing coolant to the point I have to top it up once a week. I know I have oil coming out of the valley gasket too but the leak is tiny... if messy. Slight tappet noise I can get fixed at the same time.

I'm told the most likely scenario for the misfire is a head gasket leaking coolant into a cylinder, causing a misfire on startup which clears as the water gets evaporated.

What are my options? Fix it or replace it? Bear in mind it's LPG so lots of labour to whip the top off.

Easy
Whip off heads and see if liners have dropped

Just take the plugs out the clean one is the offending cylinder.

wammers said:

Just take the plugs out the clean one is the offending cylinder.

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You're thinking duff plug so check this before more drastic action? I'll do that, cheers.

+1 wammers the clean plug is the one with water entering the cylinder

chasman said:

You're thinking duff plug so check this before more drastic action? I'll do that, cheers.

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No i am thinking plug steam cleaned = water.

wammers said:

No i am thinking plug steam cleaned = water.

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Oh. If it wasn't LPG I'd have a go at using RAVE to do the job myself. As it has a nest of extra pipes with high pressure gas inside all over the top I'm looking at a big bill for someone else to do it... or just sell it. Bugger... I'm really quite fond of it.

Find a nearby LPG engineer, get them to remove the extra pipes, then do the head yourself.

If the engineer will let you, watch as he does it, make notes, take photos. You will still be able to drive it home on petrol. When you've solved the problem you can re-install the LPG yourself, take it back to the garage to check over before you us switch over.

The clean plug test might just mean you only have to do one head?

Best of luck!

Just remove the LPG pipes yourself, it's really not high enough pressure to worry about. As long as you put everything back the way you found it you'll be fine.

Run engine on LPG, close tank valve, wait for engine to die, this will ensure the LPG lines to the Front end equipment is mostly empty of gas (may still be a tiny amount left).

Carefully crack open the Filter housing (liquid phase to Vapouriser/Regulator) and you may get a small hiss of gas...this has now fully depressurised the Line from the Tank to Vap....now open the Gas Phase Filter to the injectors, this will then fully depressurise the line from Vap to injectors...job done....

This is how I do my OMVL system on the BMW for Filter Changes...never had to do the L322's LPG system or the P38's yet although they are due Filter Changes(and when I had my Classic, never did that one either!)

Best to get a garage to do it for you, all they would have to do is depressurise it for you, the rest is just nuts, bolts and pipes clamps!

Thanks for the encouragement everybody, I'm feeling more optimistic now. Off to search for a set of gaskets made of carbon fibre, Kevlar and angel tears... like I do!

chasman said:

Thanks for the encouragement everybody, I'm feeling more optimistic now. Off to search for a set of gaskets made of carbon fibre, Kevlar and angel tears... like I do!

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As you say, don't go for a cheep gasket....stick to a good name like Payen...

I think I might build a new engine so I can take my time and still use the car... what's the best way to go about that in terms of new/reconditioned/remanufactured parts?

I wouldn't buy anything until you have stripped it ,could have a cracked liner

If someone local and reputable has offered me a new short engine, fully rebuilt with top hat liners, fully fitted with LPG reinstated for £4,250 does that sound reasonable or pricey?

chasman said:

If someone local and reputable has offered me a new short engine, fully rebuilt with top hat liners, fully fitted with LPG reinstated for £4,250 does that sound reasonable or pricey?

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Pricey

bearing in mind that your problem is more likely to be in the head than the block, I wouldn't spend that sort of money without finding out where the problem actually lies.

Thats a bit excessive price wise.....

Thing is I need the car to take my Mum to medical appointments. That means I need it out of commission for the shortest possible time. While stripping it gives me an answer it leaves it off the road in the worst case scenario. Building my own engine as I mentioned earlier or buying a short/long engine means it's only off the road for the duration of the switch over. What's the going rate for an installed short engine with LPG reinstalled? £2k-3k Who has a good rep for quality?

chasman said:

Thing is I need the car to take my Mum to medical appointments. That means I need it out of commission for the shortest possible time. While stripping it gives me an answer it leaves it off the road in the worst case scenario. Building my own engine as I mentioned earlier or buying a short/long engine means it's only off the road for the duration of the switch over. What's the going rate for an installed short engine with LPG reinstalled? £2k-3k Who has a good rep for quality?

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Sell it and buy a Smart car.