Oh no! Loss of compression in 1 cylinder ! Ring damage !

[Geoff Bragg Donating Member Find all posts View Profile Close Geoff Bragg]

After about 7000 km of vege oil, finally something bad happens that makes me wonder if I should ever have done this.

Before anyone says "it was going to happen anyway", the engine has only done 167,000km, so pretty unlikely to have happened without vege oil.

Hard starting, checked all the glow plugs, all ok. HUGE amount of oil vapour coming from oil filler cap opening. Blow-back when dip stick removed.

I must have lost a ring or two.
I'm going to pull the head off in the next week or so and have a look if I can replace all the rings without the need for a re-bore.

If it needs re-boring, it is a nightmare scenario.

The oil mustn't have been burning properly.

I'll keep you posted.

[Qwarla Senior Member Find all posts View Profile Close Qwarla]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

rings may be ok. Could be a case of pistin broke.

Might have a small hole in the crown. Either way it's not a good thing and is gunna be a bit of work to fix.

[Fitian Was here Find all posts View Profile Close Fitian]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Sorry to hear of such bad news.

I am not sure I understand your conversion setup at your signature.

Could you please explain it a little more.

Are you sharing fuel on one filter or using separate filter for each fuel?

Regards

[RODEONICK Too Busy To Bio. Find all posts View Profile Close RODEONICK]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Geoff, sorry to hear the bad news buddy. If you require any extracts from the factory manuals i have direct your queries to fitian as he has them at the moment.
I would have to agree about it being a bit premature mate crikey my old 94 model i sold with 340,000 on the clock going strong and my current 2001 has over 220,000 kms going strong. i think the rodeos get a re-sleeeve rather than rebore. Being a direct injection motor it possible you have the terrible polymerised piston rings. I would suggest you run straifght diesel and rev the **** out of it it might help free up sticky rings. mine is not liking the cold starts on b100 so i think it will be 10% dino as it gets cooler soon. you can pick up a brand new long motor off ebay for $3000 so maybe thats a better option then overhauling. Keep me posted geoff and anything youy need just ask.
Goodluck
Cheers Nick

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Use a compressor to identify where the problem is located. Apply air to the injector or GP hole (oops DI engine - may not have GP) and listen for air at the rocker cover (via the sump) and exhaust (via valve). Either repeat for each cylinder to identify which cyl is faulty or use a compression gauge to identify the faulty cyl. Diesel Comp gauges are failry rare, so probably easier to use the compressed air.
Tony

[dagwill Senior Member Find all posts View Profile Close dagwill]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

i deeply sympathyse
the suggestion of using dino and a good rev wont hurt
also i believe water injection helps clean the engine,, as you plan to pull the head off, trying a few things might save a huge amount of work.
do a bit of reding on this but i would try say setting the engine to run at say 2000 rpm and simply pour water in the intake, maybe just use a hose but start of slow, i mean you couldnt just turn it on flat out or youd hydrolock and do big damage. but tread lightly and it might just clean things out

[Geoff Bragg Donating Member Find all posts View Profile Close Geoff Bragg]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Thanks all for your advice and concern.

Thankyou Nick, I think the manual you sent me has all the torque settings for the bolts I'll be undoing. If i need more I'll get in touch with fitian.
I'l be speaking to Fitian on the phone soon anyway I hope.

Dagwill, I'll probably just clean each of the pistons manually, since I'll have the head and sump off anyway - I'll need to inspect all of them for polymerisation and damage while I'm there. But good idea - i had toyed with the idea recently - before the damage, but now.... well - bit to scared..


Oh yeah Nick - regarding revving the **** out of it, it happened by itself, and actually cleared a tappet noise that presented itself around the same time as the loss of compression. Driving along at 100km/h , engine starts to die, I put clutch in and move off the road, then the engine revs to top of scale for about 5 seconds. I think I discovered what it was when I pulled the horizontal pipe above the rocker cover from turbo to inlet manifold out..... There was a pool of condensed engine oil that had (i assume) come through the rocker cover vent tube to the turbo inlet pipe. It must have spilled over into the inlet manifold then supplied a burst of unregulatable fuel to all four cylinders. never heard a diesel rev so fast !


Fitian, i'll edit my signature so it explains it better.

[Captain Echidna Senior Member Find all posts View Profile Close Captain Echidna]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

This is probably a good warning but to people who want to use veg not to do it because it wrecks engines and costs you heaps to have them fixed

I have done about 60,000 ks in my merc, uses more everything than it should (has from day one used 15L/100 diesel) still going strong, and have saved at least $10,000 in fuel

I think it is now impossible for it "cost me heaps" as I could buy 3 mercs with what I have saved, and so far no sign of a wrecked engine (touch wood)....

Sorry to hear about the Rodeo. Best luck in fixing it.

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

"1992 Rodeo 2.8 Turbo Diesel SVO, dual tank, 3m copper pipe in pipe HE from vege tank to engine bay, 6 way pollack valve, OEM water separator, OEM fuel filter, 20 F.P.H.E before I.P. Digital thermometer with probe clamped to IP fuel inlet. I switch to vege at 40degC. Runs at 70 to 75 degC. Switch back to diesel 3km before home."
From the above it appears the pollak is before the OEM water separator, OEM fuel filter and 20 F.P.H.E. If so this means you have OEM water separator, OEM fuel filter, 20 F.P.H.E, IP and some length of fuel line full of veg when you switch back to diesel. I wonder if 3 km purge is enough. Perhaps you have been starting on a high percentage of veg, still left in the system after a 3km purge?
In my opinion it would be better to have separate filters etc. for veg and diesel, leaving just a short-ish length of fuel line from pollak to IP.
That's what I have and I only purge for 700m and it starts well on 100% Bio next morning, although it only gets down to around 14oC here. I know it gets much colder in Armidale.
However my point is, perhaps you are starting on a high percentage of veg, which is not good.

Cilinder leakage test as suggested by Tony is a good idea. If you don't have access to compressed air and a leakage tester perhaps get a garage to do it for you. BTW if doing it yourself you need the piston at TDC on end compression stroke and engine 'locked' to stop the piston descending - perhaps in 4th gear and handbrake on hard.

However oil vapour and blowby from dipstick tube tends to indicate rings or piston, not valves.
$3000 for a brand new long motor sounds like a bargain, esp if you have piston or bore damage. My son just paid $3200 for a second hand hilux 3L (2.8) complete engine (6 mths warranty) but that did include a good IP. (the old IP was buggered).

Good luck with the investigation.
Hopefully it is just stuck rings and no bore damage.
Keep us posted - we are all worried, for you and for ourselves.

[High Compression II Junior Member Find all posts View Profile Close High Compression II]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Geof-

Sorry to hear of your problems....

Always saddens me to hear of issues that may have been caused by running veggy......

Thinking about your installation/conversion. Its been mentioned before in the thread, that maybe the oil contents of your entire system (Filter, H.E. etc.etc.) may be a contributing factor Even though you have been pretty wise to allow 3K for purging....

The way I look at it,-- If for instance, your system needing purging, (Filter H.E. and I.P. etc) contains say 1 litre of veggy--Not an unreasonable assumption, considering the contents of just a fuel-filter,--It takes a surprising amount of fuel flow to 'flush' through...

To get to a 50/50 concentration at the pump/injectors, you would need to flow 1 litre of diesel fuel through the system. For a 25% veggy to diesel blend, you would need to flow 2 litres of diesel through the system, and so-on......

The incoming diesel will mix with the veggy in the various components rather than just push the veg out, particularly in the filter or the pump, where it gets all mixed up.....

I'm sure its possible to re-plumb your system, to effectively have the H.E. and the pump needing flushing, and add a separate filters for the diesel and veggy dedicated to just that fuel, thus taking quite a large quantity out of the equasion that needs flushing through....

The temperature at which you change to veg also plays a major part. The engine must be up to Full working temp Before change-over, and any cold-running faults, say like a faulty coolant thermostat should be rectified.

If you suspect in any way the efficiency of the injectors, they should be re-built with new nozzles especially if they have done more than 60K miles. --and set to Standard pressures--Wear in the nozzles may not affect operation on diesel much, but will be mega amplified when 'on the veg' It doesnt take much in the way of carbon build-up to stuff up the spray-patterns

A timing advancement of 3-4 degrees above makers settings will also help to compensate for the extra time veggy takes to combust properly, reducing the unburned veg present in some cases...

Thinking about your current faults...

You may get lucky--Could be just the head-gasket....

Not all engines breech the gasket into the water-ways--You may have blown it into an oil return channel/gallery which would give the same symptoms you describe....
A leak-down test will tell you exactly where and on which cylinder the pressure is being lost....

Best of luck with it anyway.....

[Fitian Was here Find all posts View Profile Close Fitian]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Fitian, i'll edit my signature so it explains it better.

I see now.

It is obvious now that you were not actually purging the system fully.

In my setup I only have a 20 FPHE after the pollak valve and it takes good 3 kms to fully purge the sytem.

So having a water separator, fuel filter and a 20 FPHE will need around 10-15 kms to be fully flushed out.

I always advise against changing over to veg oil at below 60 degrees C but some other members reckon it is okay. This is not right.

So I think you were changing over too early. And you origianlly were starting on cold veg oil not diesel going by your purge time 3kms.

I hope this does not end up costing a lot Geoff.

Good luck buddy

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

You may get lucky--Could be just the head-gasket....

Not all engines breech the gasket into the water-ways--You may have blown it into an oil return channel/gallery which would give the same symptoms you describe....
A leak-down test will tell you exactly where and on which cylinder the pressure is being lost....

Best of luck with it anyway.....

Right on. I had forgotten about the possibility of the head gasket. I have seen them blow to the crankcase. It's been a while since I worked in the trade. If it turns out to be that I don't think you can blame the veg. If it is stuck rings you probably can blame veg, actually starting on a high percentage of veg.
Reducing purge volume should be a high priority as Fitian recommends.

[High Compression II Junior Member Find all posts View Profile Close High Compression II]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Why not? the veg is already getting blamed and the problem hasnt even been properly worked out yet. best to blame the veg because it is getting too hard for people to get so should make some balanced story to keep people away from it instead of getting more people doing it all the time.

Sorry Dave, Dont quite get your point there....!

Maybe I'm just being a bit stupid today.....

If its he H.G. then its unlikely the veggy was the cause.....

[Captain Echidna Senior Member Find all posts View Profile Close Captain Echidna]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Sorry if I have misinterepeted anything, but heres my 2c worth.
I used one filter for 2 lots of fuel. I found after about 1000ks "flushing" (Ok I was running) on diesel there still was a lot of veggie oil in the bottom of the filter/ sediment area. I dont think these can be flushed, you need 2 one for each fuel.

The fuel return from the injector pump going to the tank or being looped will make a difference to the purge time. If its looped and returning veg oil to inlet of the fuel it will take a long time to flush as the moment you flick the switch to purge you are running on 50% veggie oil (assuming the injector pump returns as much fuel to the tank as it uses) (as I write this I cant see on your signature if its looped or returned, but it could guide others)

I purge on my landcruiser (80 series turbo diesel 1HD-T) for 5ks, and sometimes on startup I wonder if I can smell veggie oil. I have seperate filters, so only flush the 20plate FPHE, injector pumps lines and return to the fuel tank. I guess I also use a lot of diesel so mixing is less of a problem.

[spock505 Senior Member Find all posts View Profile Close spock505]

Re: Oh no! Loss of compression in 1 cylinder ! Ring damage !

Oh yeah Nick - regarding revving the **** out of it, it happened by itself, and actually cleared a tappet noise that presented itself around the same time as the loss of compression.

Hang on before you pull the head off, these two incidents are almost certainly related to each other.

Hydraulic lifters could, given the right circumstances jam open causing a total loss of compression through one of the valves - the tolerances are small and if you have a worn lifter depending on its design and then given a good rev could 'lock' getting rid of the noise but no longer workingn locking open.

Remove the rocker cover and see if you can get a feeler gauge through when the lobe is away from each lifter.

40c is way too low for a change over, would agree with Fitian 60c as minimum.

Best of luck,

David