Thanks for the response Aragorn, just read it, I've been away (Brighton) for a couple of days.
Tend to find most engines have a bit less oil pressure at idle rpm than just above idle rpm anyway?
Also engines that use an electric fan usually have more of a temperature rise/fluctuation sat idling than those with a thermoviscous fan?
Can see why yours could have the feedback loop.
On said forum people are now talking little end knock. Personally I'm not convinced it's even bottom end related, could still be top end. On other forums for vehicles with a very similar engine (VQ35 but in a different state of tune) they talk of valve clearance issues and valve train noise, I reckon there's a chance it could still be something like that.
Thanks, Simon
I don't want to hijack this thread, seems the concussions have already been made?
On another forum, different make/model vehicle (sorry!).. a guy I know seemingly has a big end knock but this came to be at around about the same time as an overheat situation. So a leading question is, did the big end problem cause the overheat or did the overheat cause the big end problem. Thoughts on this? As some as you will probably expect from knowing me, this is a Nissan VQ35 engine. It isn't as though the big ends are effected by anything much besides oil eh?
Edit - (heh!) and while I'm at it... I've got 2 same model vehicles (Nissan Elgrands) with the same engine. I've already had to swap the engine in one of them (long story but I wrote about it in detail on this forum a few years ago). The same one I did the engine swap in started occasionally overheating, it was loosing coolant and the rad seemed to have a slight leak at the bottom so I changed the rad and thought 'job done' but the same overheating and coolant loss has occurred since... I drove 350 miles towing my caravan last year but had to stop every 50 miles to let it cool down enough to add fresh water. I've not used it much since, when I have it's been fine except for hard top hose. I did a sniff test which as expected proved positive. I now (when I get time) intend on pulling the inlet manifold to make access to plug hole areas easy then pressure (drop) test the cooling system and check to see if I can find which cylinder(s) have a tract to the cooling system. Maybe then if the problem is just on one head I might change the HG on only the problem head.
Years ago a P38 owner I did some LPG work for told me that he bought a 'power increase and drive-ability improving module' from Ebay for his P38 which wired to the maf sensor. It turned out to be just a 5watt resistor and he knew it wouldn't do much. But that didn't stop him buying a few dozen 5watt resistors and listing them on Ebay as P38 power increase and drive-ability improving modules himself, he sold the lot, made a quick tidy profit and had no complaints.
Some of us have already seen this link posted on LPGforum by Avensist https://www.glasgowtimes.co.uk/news/scottish-news/20055908.glasgow-taxi-drivers-forced-off-road-amid-lpg-fuel-shortage/
Whatever the issues are the suppliers are not doing themselves any favours by not keeping forecourts stocked. Situation is a bit like selling air to the crew of a space-station but not supplying them for a few months then wondering why they've got no customers left, they will undermine their own current customer base and potential future customer base... I doubt many more city councils will now be considering allowing LPG converted taxis to enter emissions zones and that will have a knock on effect for the rest of us.
Edit - Not that taxi drivers would want to go for an LPG conversion after the Glasgow situation anyway.
Gilbert, in case you're online but haven't noticed I've PM'd you about a different matter.
Good write up and interesting Gilbert.
If you don't mind me saying - Fuel trims and fuel computer mpg readings can both be effected by the stochiometric ratio and calorific value of different fuels. Exhaust temp from the engine itself can be effected by the type of fuel, the mixture and ignition timing but the cat can generate extra heat itself doing it's job of cleaning up emissions... On vehicles fitted with a cat temp sensor you can see that although exhaust temp may go down with rich mixture (so the input to the cat is cooler) the cat temp can still increase with rich mixture (the cat has more HC's to clean up so the cat can get hotter than with lean mixture). The cat can get hotter anyway if it's got more exhaust gas to deal with because the engine is running under higher load (again more work to do). .
You can get hydraulic pipes (including PAS pipes) made up by firms such as Pirtek. I've had a few PAS pipes made up by them. Take your old pipe in complete with end fittings, they have a vast range of end fittings on the shelf and 99% of the time will have an end fitting that matches your old ones so have no trouble matching your old pipe.
Most such firms can even come up with pipes to replace sections of AC pipe.
It's a bit alarming to hear about P&O, I don't know all the ins and outs but on first consideration it doesn't seem legal re UK employment law what they're doing. I also see this as likely the end of P&O. Not that it's really relevant or an important factor but I have to wonder if this could also have minor impact on my business, because if people wonder about being able to get their LPG converted vehicle abroad in future (and since they can't take their LPG vehicles through the Chunnel) there's the possibility a minority of customers could be put off LPG conversion.
Gilbertd wrote:
A wet compression test can be inconclusive on a Vee. Ordinarily the oil will seal the rings so if the compression goes up, it's ring, if it doesn't, it's valves. But with a Vee engine the oil will sit at the bottom of the bore so not seal the rings anything like as much. If you put a lot of oil in then the compression will go up anyway as the oil will partially fill the combustion chamber and reduce the chamber volume. I'd say your suspicion of a problem with the stretch bolts is the most likely and the gasket is starting to leak around where one of the bolts is. You'll soon know as it will come undone far easier than the others.
Agreed. Though with a RangeRover you could park it on a banking so the whole vehicle is leaning to one side thus making the cylinder bank to be tested more vertical lol.
I'm not a P38 expert but some general advice...
A poor fit on the intake manifold shouldn't effect compression readings.... You ran the compression check at full throttle anyway.
The compression problem could be valve leakage as opposed to ring leakage, have you tried a wet compression test? If only valve leakage were causing the compression problem and if only a HG problem were causing coolant pressurisation you could fix the problem yourself (whip the heads off etc).
The general advice wouldn't leave you with a top-hatted engine though.
mad-as wrote:
and where are you going to get gas from when Russia turn it off or do you get it else ware? how much of Europe and England get fuels from Russia?
As Gilbert implied, that's natural gas (methane, CNG, LNG) though... As opposed to the LPG we run on.
Been said on LPGforum that recent LPG shortages at forecourts have been due to home heating customers having their home heating bulk storage tanks filled early before price rises, the delivery drivers have been busy filling home heating tanks, suppliers prioritise filling home heating tanks over filling forecourt tanks. But if so many home heating customers filled early then since we are heading into summer when people won't be using as much gas for home heating then home heating customers won't need to refill their tanks again anytime soon so there should be plenty of LPG for forecourts... hopefully!
I filled 3 vehicles with LPG this week so far, had to fill 2 of them at Shell Redbeck near Wakefield because it was later than 8pm and Morrisons kiosk closes at 8pm. Recent price rises at Redbeck for LPG from iIrc 72.9 to 74,9 in a couple of steps. But petrol also went up and is now around £1.65, I also saw a guy taking a pic of the price on the pump when he filled with super diesel, had a look at the price when he'd gone... it was over £1.81 per litre.
Just a bit! 53P per litre would be great these days, I've got used to the new normal of LPG in the mid 70's pence per litre.
I was already booked until September before 'recent events'... Now I'm completely inundated with phone calls, emails, forum messages, etc, people whom are suddenly interested in converting to LPG asap.
Thanks Leolito :-)
leolito wrote:
Hi Dave, welcome to the den of P38s.
A little hijack - Simon very very nice website! I will dig into it when time allows, is packed with lots of info!
Thanks, it's been so long since I've looked at it myself that I've forgotten what I've put on there! I know it looks amateurish and has some dodgy formatting and broken links but I leave it as it is because a lot of people say there's good info on there and because I haven't got time to do anything with it. I regularly get firms emailing me to say they've reviewed it and could bring it up to date or optimise it for Google searches but unless I sat down with them I expect I'd end up with a cut down site that looked like every other LPG firms website. It used to work better with less dodgy formatting but I let someone I know have a go at changing it without changing any of the wording or sections etc, and I think they made it worse than it was before...
Thanks Richard (Gilbertd),
A problem may be that I am fully booked until September at the moment. Been a while since I did a P38 now, would like to do another.
Cheers, Simon
Only kidding with this...
I believe you can get the same fault code if mixture is incorrect due to a lambda problem too? In that case the MAF will read higher than usual airflow because the airflow really is higher (rather than the problem being duff Maf)... When mixture is incorrect (especially if lean, not so much if slightly rich but again if very rich) the engine needs more air to make the same power and more air to maintain idle speed.
Interesting about the Jap import, I work on a lot of Jap imports (usually Jap made cars like Nissans etc), it didn't occur to me before but have any other P38 fans considered importing a P38 from Japan? Jap imports are usually in great condition for the age.
Welcome Pete.
I wouldn't mind a few lez exemptions in my cab ;-)
Gilbert has a point though... The taxi exemption is a recognition that EV's wouldn't be suitable for taxi use, but if Joe Public needs to use a vehicle for similar range etc that a taxi might cover they get no exemption.
If I were to visit London, why would it be better that I parked my LPG converted car on the outskirts then got a taxi to pick me up and and drop me off at an inner city destination than if I just drove my own LPG converted car to the inner city destination? Fewer vehicles in the inner city maybe but no worse from an emissions standpoint. But from the number of vehicles on the road standpoint - if I had to drive to the outskirts, park my car, then hire an EV to drive into the inners that equates to one extra car on the road in my book?
Not just London, similar schemes exempting LPG converted taxis but not LPG converted private vehicles are being rolled out in Leeds, Manchester, Bristol, Birmingham, Glasgow. At least there's the upside that the LPG refuelling places taxis use on outskirts will usually be available to the public.
Some of the taxis (well, private hire vehicles) have direct injection engines that use a bit of petrol all the while they're supposedly running on LPG anyway.
Some of the LPG components suppliers are partly re-modelling their businesses to meet the demands of taxi LPG conversions. One supplier in the Birmingham area told me 2 installer firms that just they supply jointly convert over 200 taxis to LPG every month. The supplier is offloading stock to make space for the specific sized tanks etc that are fitted on the taxis, they recently sold me 20 large LPG tanks at a knock down price just to make space for the taxi tanks.
Edit (OK I've already edited/amended a few times but they were shortly after posting and this is a while later)... Some of the private hire vehicle LPG conversions aren't going to do the trade or impression of LPG converted vehicles any good, they're making about £200 profit on a conversion and the conversions are going to have some problems.... But the private hire drivers won't mind driving around with engine warning lights on and they've achieved the biggest reason they converted to LPG (avoiding higher emissions zone charges) even if the LPG system doesn't actually work. A driver who delivers parts to me realised I did LPG conversions and asked if he could pass my phone number on to a guy who is involved with taxis / private hire vehicles in some way, sure enough the guy phoned me up and offered me 40 taxis to convert if the price was low enough... My price wasn't low enough and I didn't expect it to be, nor would I really want to convert 40 taxis for such little profit with the prospect of converting yet more taxis after the initial 40. The LPG scene will get an initial boost from the taxi conversions but in the long run they're going to mess up the entire scene for the rest of us. .
Chrisp38 wrote:
I'm not very good at this internet thing ^^^^^^
Have I messed up? Have I linked to my bank account?
Yes, £100 withdrawn thanks! 😉
I expect Gilbertd will be along soon and edit your posts so that your pics can be seen without having to click on them.
Did well there! Imagine if the leak were not on a visible side of the compressor, in that situation I'd probably keep looking around other parts for ages before thinking about replacing the compressor.