Im back i think + a cautionary tale.

[Budgetbond]

Soz ive not been on here for a while i noticed a few issues with my car ive endeavoured to fix whilst coincidentally running around in another car acquired for my nephew.
So having finally getting my car sorted out id diy-converted i noticed a few concerning symptoms i thought i better try and address asap if i was going to try and run it long term on lpg.
Having converted it myself and having experienced a few overheating type occurences and running lean periods in the interim and without initially taking the trouble to fit a flashlube system (toyota vvti engine-its recommended) i noticed a few symptoms worth watching out for 1) a previously notoriously tappetty sounding engine had gone quiet (a tappy engine is a happy engine) 2) all of a sudden severe blowby when oil cap removed.
I knew something wasnt quite right so i thought id take it off the road and try and investigate/fix.
I feared i mite have burned a valve with running hot so i initially bought a boroscope (i was going to try and put up the pics/vid on here) but the resolution of the pics in the cylinder werent conclusive enough and although my valves didnt look great at all, it seemed like i was still getting compression in the cylinders.
So i looked into adjusting the valve clearances myself, having taken the valve cover off and confirmed they were now out of spec, and realised after initially consulting the manual, when broken down there could be an easier/less expensive way of doing it myself.
(With my engine valve clearance adjustment shouldnt ordinarily need to be performed but if required its a bit of a barrier as its a cam over bucket design with each new bucket potentially costing 30quid each)
Anyway altho id do it even better next time i think ive managed to do it and altho im on hols at min in my other car im back running again hopefully.
The cost and hassle of valve clearance re-adjustment is a bit of a barrier to long term running on these engines, so if anyone else wants to know an easier/cost effective way of performing it ill let em know.
(I also have maybe thought of and performed an innovative fix for notorious oil burning on these and similar engines without requiring a rebuild at the sametime altho this is yet to be confirmed so if thats succesful i can maybe post that up also)

Hope everyones been running well

[Brian_H]

The cheap boroscopes that can be found, are pretty much what you'd expect. I've had use of a couple of them, and you may as well not bother as the image quality from them has been so poor that they are no real use at all. You'd do better with a compression tester really.

You were pointed towards valve saver for good reason - I've run a Ford Zetec for 80k with valve saver and that was fairly problem free (though that is a shimmed design and requires checking every 90k - which roughly matches up with when it was noticed to be a problem with clearances).

Blowby would be piston rings usaually though wouldn't it, and given the oil burning I'd have thought that a likely concern anyway?

[Gilbertd]

The pre-2003 1ZZ-FE engine does suffer from piston ring wear anyway, something that was cured with a piston design change from 2003 onwards. Toyota also changed the recommended oil from semi to fully synthetic and reduced the oil change intervals.

[Budgetbond]

Thanks for the replies ive only just noticed them for some reason.
Yeah, ive restarted my car after my hols, and its running ok albeit s idling high.
Its on a SORN at the min but ill stick it thro one more mot to hopefully get just another year of running out of it. (With a view to maybe run lpg better on another car afterwards)
But yeah i can confirm you were correct that running without valvesaver (probably within 10-12k) under the wrong circs (initial incorrect diy setup and prolonged lean running) even driven sympathetically can lead to vsr.

However a valve clearance adjustment can rectify this and can be fairly easily diyable even with under camshaft bucket lifters.

I also tried a fairly novel intrusive treatment to help with oil burning that doesnt seemed to have worked.

My car does seem to be still white smoking ive been trying to fathom out for a while but i think its just oil burning which has been masked by an oil leak ive now rectified.
Can anyone confirm nowadays that synthetic oil burns more whitish nowadays rather than blue?
(Im obviously going to monitor oil consumption from now)
The only thing is after my valve clearance adjustment its running well but my cars now idling high (1800rpm) and doesnt go down when warm, ive been trying to fix this but not completely successfully.

Ive tried cleaning my IACV, my maf, changed my pcv checked for vac leaks everywhere to no avail, plugged and unplugged various sensors, (its defo not my coolant temp sensor) i thought id fixed it but its back idling high when everythings back together.

Anyway when i come back to running it ill update on this issue, but its now idling high either due to something now done not quite right after the valve clearance adjustment or thro just being sat which i think is prolly vv unlikely now.

Anyway ill update again on this issue maybe when i come to run it again.

[Brian_H]

The problem with VSR isn't quite as simple as the valve recessing in a uniform fashion from what I'd gathered, more a case of uneven wear or in particually bad cases burnt valves which then don't seal properly. The problem is that some engines are literally just hard enough to withstand use on unleaded fuel (And some don't quite get that level right after extended mileage either) and will suffer on LPG as you lose the cushioning effect of the soot etc you would have on unleaded.
Most Japanese engines need valve saver as a result, most Fords are also recommended to use one, as even on a well calibated install they will have VSR after a while. Badly calibrated or out of spec components (eg used worn injectors for example) would likely acclerate any VSR as well.

Is it really white smoke? - you will get steam from burning LPG, and when I've had ignition issues the steam is much more noticable in quantity particually at idle on cooler days.

I'd really suggest you see if you can get a compression test on it, you can buy basic ones on Amazon and the like fairly cheaply. Avoid the silverline branded ones, the one of those I tried was hopeless (wouldn't even indicate the same compression on the same cylinder on subsequent tests or even near the same as you'd expect).

I also tried a fairly novel intrusive treatment to help with oil burning that doesnt seemed to have worked.

Would you care to elaborate on this? What have you done and what do you mean doesn't seem to have worked?

[LPGC]

Just finished conversion of another Toyota Alphard with the 2.4 2AZ-FE engine.

Fitted a lube system with a 4 way splitter.

[Budgetbond]

Cheers for the replies i was going to get round to fitting a valve saver but was temporarily seeing how it went but ve obviously created the wear in the interim setting it up myself but points well taken.
I was going to post pics/video inside my cylinder taken with my boroscope but they werent quite definitive enough, but my valves didnt look great partic the exhausts, black with carbon with wear round the edges but not quite clear enough to see if they were definitively burnt. (Ie. With holes, i can try and upload any pics/vids if anyones interested)
I did a basic compression test with my compressor (leakdown) and there was no obvious leakage so to some extent ive still got compression in all 4 cylinders, but yeah Bri a compression test would be illuminating.

My cars been white smoking for a while (a friend notified me initially after following me i mite have even opened a thread on it here).
And its definitely white/grey smoke, no blue, no coolant loss, when warm/cold on petrol and lpg.
I thought it couldve been a stuck open fuel injector (perhaps wiring shorted) but i dont think it is from what checks ive done.
But any oil burnings been masked by an oil leak from my sump ive now fixed.
So altho my cars a later 2006 example theyre well known for potentially oil burning.
So when i was doing the valve/sump work i initially gave the cylinders a good piston/valve soak, which then became a good oil flush, and before dropping the sump i filled my engine up with diesel to try and clear out under the pistons, but on dropping the sump i came up with the idea my research hadnt come up with to reach up and probe/try and clear the piston drain holes up underneath the piston, its not easy but possible.
But anyway its still white smoking so if it is burning oil which im going to monitor it hasnt worked. I suppose it might initially be residue burning out but am going to monitor it.
So my cars back running again but high idling after my valve clearance adjustment i cant quite fathom out yet but when i start running it again ill see how it goes.

(Soz about the lingo im having to fire this message off quickly)

(Oh yeah those 2.4 2az-fe s are also notorious oil burners under the wrong circs)

[Brian_H]

Doubtful you'd have holes in the valves themselves - burnt valves are usually damage to the edge where it meets the valve seat, usually ending up with a profile that doesn't sit and seal properly, Really bad cases they will burn as well and lose the correct shape as well but doubtful you'd have anything near running right at all if that was the case.

As said above - I've tried a couple of the cheap boroscopes and it seems they are something that if you want a decent one, you have to spend more money, the video quality of the ones I've tried was far too poor to make much sense of. Might prove useful if you were trying to recover a bolt from a manifold or similar, but to assess damage no real help at all.

[Avensist]

Just wondering, those engines that already burning oil, would that burning acts as valve saver? Obviously it depends on the severity of the burning but valve saver is like burning oil.

As for the idle issue for Budgetbond, I know this sounds daft but when you did the valve clearance adjustment, you did mark the timing chain and the gear when removing, and on refitting, you have double checked everything aligned back again right? Also the chain tensioner is correctly re-activated as well?

[Budgetbond]

Thanks for replying, yeah my valves dont look great ill try and upload pics/vid in due course for future ref, theres definite erosion around the valve edges, altho i can tell there is some form of compression what it actually is would be illuminating, but power seems to be back on my car which id noticed had been down/flagging.

Ill update more when i come to running it again which im hoping to do (i think by my previous calcs its worth a potential fuel saving of upto 600 quid a year).

Yeah i believe and can imagine avensist that actual oil burning itself and fumes coming back thro the pcv system is going to act like a valve saver. I was trying initially to see how i got on without it and trying to be sympathetic, but i think like the oil burning you only need one period of unideal running circs and the damage can be done. (And running lean i suppose/presume).

The idling ive tried to rectify i thought id fixed it but now its back together seems to be back. (Idling at 1800 rpm constantly).
Im going to try and address it more when it comes to running it, but it could be a myriad of things from the valve clearance adjustment id do better next time.
In regards getting it to TDC it took me ages in trying to get the arrows to line up exactly until i realised on youtube etc i dont think they actually do/its v hard to see, i think the main point is that you make sure the chain doesnt skip a tooth/cog in relation to each other which is fairly easy and was v careful not to do right upto the end almost, im obviously assuming it isnt anything to do with that, im not 100% sure how id check and if i could rectify it if it wasnt the case.

[Avensist]

You could get a Mini-Vci which is inexpensive which works with Techstream if you haven't got one. It is an enhanced OBD II stuff that dealer use and provides you various information as well as tests. I got one via Amazon.

You say you've already checked the coolant temp sensor but with Techstream,you can see the live stream data reading as well as monitor fuel trims, kill particular injectors, manually control VVTi actuator etc. This should give more information to diagnose your problem.

[Budgetbond]

That sounds v interesting avensist cheers and what i need ive been thinking about a better obd reader you havent got a link by any chance have you?
Ta

[Avensist]

I bought mine very long time ago but if you search for toyota mini-vci it will come up. Had to get it when my next door bought a Prius and had ABS issue. The Techstream not only does engine but the whole like gearbox, brakes, including programming etc.

[Budgetbond]

Thanks yeah and cheers for the tips ill update back on this when hopefully i come to run it again