Hello all.

A couple of weeks ago we were driving our FFRR and the heater didn't work, didn't think much of it but then later on it started to overheat, we were on the M4 with a newborn baby so drive a few miles to pull over safely at the services before getting recovered.

It is an '02 V8 petrol with an LPG conversion.

It has been with a 4x4 specialist who didn't look at it straight away

There expansion tank cap has been replaced and also the radiator.

They've run it up and coolant is circulating but continues to rise in temperature.

They say they know that hydro carbons are in the system because of how the coolant is behaving (not sure how) but haven't done a chemical test.

They're now saying that it is a head gasket issue, although they haven't explored it because they have had very low success rates with head gasket repair in the past. They're looking for a second hand engine & contacting a customer that had theirs reconditioned elsewhere,

Does anyone have any experience with re-builds, engine replacements or do they just plain know that there is an easy solution or hack that should be tried??

They probably don't want to do it because of the Vanos system and the special tools and knowledge required, if you shop around I'm sure you'll find someone who will do the head gaskets...

A total rebuild seems a bit excessive for a failed gasket....

A second hand engine is a lottery....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thank you Halyards, oddly enough I have just been admiring your post about your winch install!!

So there is no issue with reconditioning due to the aluminium the engine is made out of?

Haylands**

Lots of folk still think the M62 engine had the nikasil treatment and you can't do anything with it...

It didn't, and you can, this has no bearing on changing a gasket though..... Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

just got your message, from what i do know about your problem, the engine is indeed aluminium, and the bores have a coating. meaning, that you cant really rebore them, so to 'recondition ' the engine, might mean less than you think.. not money, i mean machining. what i mean is, there are only say the big end and main bearings, plus the various gaskets, including the main head gaskets, and maybe valve guides, that can be replaced.. so, if your bores are scored, or you block is damaged, then you will need another block/whole engine.
Many people talk of reconditioning an old engine, in machine shops. these m62 engines, dont have 'oversize' parts available. so if say your crank is worn, you cant regrind it and fit thicker bearings, like old days. you just 'get a new crank' and some standard new bearings. same goes with the block. and new standard pistons
it is very likely, that with some decent checks, you can find out as to which cylinder(s) are giving you the issue, with a compression test. you can hopefully find a sort of 'back street' type mechanic, knowlegable with similar m62 BMW's like the 5 + 7 series, ( that used this same engine), but in a different setup. meaning that although you cant just plonk one from a saloon, into you rangie, but...with some major fettling, .it can be done, with extra knowledge. this would not be the direction, that a specific range rover techie would be leaning to. he would just say, get another Rangie engine.

To remove the head(s) you need a set of engine set of 'locking tools' that hold the relative engine parts steady, and allow the engine to have its heads off, and back on, and timinig chain, and camshafts, and all will going back into the correct mesh, and have no valve damage. (Mistimed engine) this set of tools cost me arounf £400 about 3 years ago. the gaskets cost about £50 the pair, (actually might be £50 each, cant remember...) these are all standard size parts. like the new crank, pistons etc.
dont be fooled by adverts for 'fully reconditioned engine' ready to fit. these may be just an engine from, say a wreck, steam cleaned off, and just sprayed silver, with say, some new rocker cover gaskets, and a few new shiny nuts added to jazz it up.
i cant really give you a diagnosis, to your issue, but can just inform you of what you might have heard, is sort of not true etc, and to maybe get as much advice, from say forums, and even some greasy mechanics and their ideas..
either way, dont try to drive it. ask for some extra opinions. typical mechanics, use a special fluid, that is in a glass vial, which is screwed to the top of the expansion tank, some blue fluid is poured into this vial, and the steam from your hot engine, is pushed through this fluid, and it will turn to say, green, meaning that your coolant has 'exhaust fumes' in it, meaning, that your combustion chamber gases, are getting pushed into the coolant, via a leak/failure in the head gasket area. This is possibly your symptom, of hard hoses, and engine trying to boil.. also, dont be tempted to buy a bottle of 'magic sealant' to pour into the coolant. this will just block your engine waterways up. and will only temporarily stop it.
you need to be very sure that you have an head gasket failure, before you go down the yellow pages, for an engine lottery ticket.


a secondhand engine, from a dismantler, that would hopefully be guaranteed for a couple of months, would be north of £1500, plus the labour to fit it.

The chemical diagnosis' is the screw on glass vial with coloured fluid mentioned in your first post ( I assume)
This may be true, but not a guaranteed head gasket failure.

Take your time, and keep both hands on your wallet.

Last edited by johnboyairey on 21st May 2016 12:31am. Edited 1 time in total

This is almost exactly what happened to mine. I was also told it may be a head gasket, without a hydrocarbon test.

DON'T PANIC!

I'll tell you what I did, and you can run through the same steps if you like.

0. Turn off LPG. Do all the following running on petrol. DO NOT take off the filler cap with the engine warm, it will boil up and you'll think you have a problem. This system runs above boiling point because it's under pressure. Release the pressure and it boils. Which is what it's supposed to do, so don't be fooled or introduce air to confuse the issue.

1. Bleed it properly. There's a lot of rubbish talked about bleeding the 4.4, but I found the best guide on a BMW site. http://www.meeknet.co.uk/e31/BMW_M60_M62_M...System.htm

Basically, make sure your LPG vapouriser is below your expansion tank top. Take off the rad cap and remove the bleed screw. Do not trust the level indicator, they break and lie (well mine did). If it's lying, you'll need a new expansion tank at some point. Put the ignition on to position 2, don't start the car. Heater controls full hot, fan off. This gets the aux pump to move coolant through the heater matrix, and your vapourizer too since it's probably tee'd off the heater. Squeeze the top hose with one hand, add coolant until it's up at the next of the expansion tank, then release the top hose. Much easier than burping it with less mess! Keep adding coolant and squeezing hoses until there are no more bubbles from the bleed screw. Put back the bleed screw and the rad cap. It will be a bit overfilled, but don't worry.

2. Test the viscous fan clutch. Get a rolled up newspaper, start the engine. Try (carefully) to stop the fan with the newspaper within a few seconds of starting - the fan goes at full speed at engine start then the clutch releases. If you can, it's the fan clutch. If it shreds the newspaper, it's something else. Stop the engine and check the bottom hose is hot.

3. If the fan clutch is OK, get the engine warm and see if the viscous fan turns fast and can't be stopped. If you can stop it, the centre of the rad isn't getting hot, so you have a clogged rad or still have air or the bottom hose has collapsed (not likely IMHO). Let it cool and bleed again.

By this point I'd replaced my fan clutch, bled it and it was fine. Yours may be too.

Then try LPG. It's possible your vapouriser gaskets have failed and it's pushing LPG into the coolant. You'll know fast - run for a few miles on LPG, let the engine cool (again, sorry) and see if there's air in the coolant.

See how you get on, let us know. Remember it could be the expansion tank leaking (letting in air), the fan clutch, the rad AND the LPG! I changed my fan clutch, expansion tank, radiator (obvious leaks) and am about to overhaul my vaporiser!

By

mr spock, that's very logical....
even better, for now, you could get the lpg plumbed out, and have no risk of the gas pressurising, meaning return the heater hoses to original setup, and run it only on petrol With plenty of reading on bleeding the system. dont forget bleed screw too.
-yes there are many ways to overheat this engine. and many tips, like an 80 degrees thremostat to keep it in check. be sure you have no leaks, and see how you go. it took me a little time, to find all my leaks, and issues. touch wood, its ok. but you might be looking far too deep already, worrying about you HG failure.

......Scotty, beam me up.....


this is the fluid i was talking about




Last edited by johnboyairey on 20th May 2016 6:41pm. Edited 1 time in total

The "light bulb" moment for me was realising the link between the centre of the rad being hot, the viscous fan and the pressurised system.

Unless you know and trust this garage I would get a second opinion. Sounds all too quick to opt for the biggest job to fix it.

Last edited by kezbo1981 on 20th May 2016 8:44pm. Edited 1 time in total

Sorry, I just re-read your original post and saw you already have a new rad and expansion tank. I'd be looking at the fan clutch as above.

Gentlemen, Thank you very much for your swift and detailed responses!

We love the FFRR & with our first child and al the activities we get up to it has been absolutely ideal!

I like the idea that it could be the fan or the LPG vaporiser.

I'll speak to the garage in the morning

So I went to the garage this morning who are adamant that it is a head gasket.

They topped up the coolant and the FFRR is running up and the heater blows warm. Then it starts blowing cold and warm again indicating that there is an air lock in a "fully topped up" system (I suppose I'm trusting that it was full and that they topped up to the LPG vaporiser as Spock suggested!)

When the engine has cooled down the coolant is low but the system is still under pressure which the garage says indicates that the head gasket has pushed coolant out through the expansion box cap. They refuted that it could be LPG in the system and they did run it up on petrol not LPG. They haven't done a chemical test but say it is without a doubt the head gasket.

Have a friend in the trade who is an excellent car restorer and has referred me to a engine rebuild company who said they will look at it next week.

Also looking at second hand engines & prices - unless anyone could give any better advice???

Topping up coolant is not bleeding. It could be leaking from the coolant pipes on the back of the engine or the valley pan gasket, although I'd expect to see some coolant below. Can you ask how much they added, and how? Did they remove the bleed screw or just add coolant? Seriously, mine went through a half a litre each time I ran it.

Hmmm I get what you are saying but I kinda get the impression that they have done the following:-

1. They've done it correctly
2. We've done it correctly we know what we're doing no need to question it

I would think it is probably 2.

Although Spock they are saying that the system was still under pressure and low on coolant when it had cooled down. Hmmm would it still be pressurised with an airlock?