WHOA there neddy........ go back to basics The car was initally driven into the shed & it was by all account operating 'normally' when it was parked ready for the pull, so something happened in that 2 week period between the key being turned off and the end of the plenum pull that has altered Oil pressure was zilch at startup & you have un-seated valves (@TDC)* with zip clearance on the cam and zero compression on all cylinders after the pull yet nothing in this area was altered / touched except the rocker cover swap & then the swap back to the original covers ( thus eliminating any interferance from the upgraded covers ) *TDC = Top Dead Centre ( both valves in fully closed position in the chosen cylinder) An oil change was done and oil pressure returned to 'normal' and 2 cilinders magicaly gained compression......... how would this be posiable if valves were bent ? ...... somehow, "just a litlle bit bent" doesnt cut it :sorry: We've had a pull together and you take more care than I do ..... rags in the ports, bah humbug ..... only do that if you have the DT's after a night on the syrup I beleive that the issue lies elswhere as to the sudden compression loss due to zero clearance on the cams and seeing that the oil change had some effect on the compression I think its more an issue in that area. The old diesel trick maybe just what the Dr orders to clear any obstructions and once done and IF the problem still exists I'd probaly release the bolts that hold one cam in place a little at a time to allow the cam to rise up slightly ..... then I'd have another gander at the valves and their seating position and I think you'll find that they will probably be fully closed. This all leads to an issue with the oil and the hydrolics...... & iliminates the bent valve theory In short: I cant for the life of me see how ALL valves could have been damaged by something being left / dropped into the ports, then by some GOD like intervention ( the oil change), 4 valves suddenly become straight enough again to give you compression on 2 cylinders only !!! Oh if only mechanicle things fixed themselves so easily :zlove: I'd happily pour a 44 over "that rattle" The only culprit that is related to ALL the symptons and at all stages of this process ..... and has magicaly altered the situation when changed, seems to be the oil..... looking foward to hearing the results after the diesel wash Kingy
3rd party interferance ..... unattended car .... the only way I could see it happening Like you I cant see how they all could have been bent and all by about the same margin, even with human interferance it would be extreamly hard to duplicate...... almost imposiable infact ! the issue lies elsewhere
huh Diesel is an oil .... ok a low viscosity oil but still an oil should be some oil pressure reading all be it low one ..... the needle should atleast move off the rest mark ! Hell, even an engine running chocolate milk ( oil & water) has some degree of oil pressure showing if not almost at the 'normal mark' The troopy had stuck rings on 1 cylinder and I tried a 50/50 wash... failed then did a 100% straight diesel wash and I had 2/3rd's of the "usual" oil pressure showing when running. The needle did move up slightly when cranking over only.... Might be a good idea to add a mechanicle guage into the equasion and see exactly what pressures we are dealing with Still having troubles with the gaining of compression on 2 cylinders after the oil change....... pressure relief valve stuck / jammed / gritty movement Failing oil pump ????? oil gallery blocked ???? .... worse = cracked Still the same filter or did you change that with the oil ? Would love to know what oil pressure you've got at the cam bearings / lifters Much diesel around the cams / lifters etc after cranking ? :bow2:
Back of the the cam cap bolts and see iw the valves close.If they do it is probably the hydraulic lifters jamed.I called past sat morn but know one there.I will try and call past during the week.
This problem hasn't made any sense from the start. something is going on that no-one including the op know about. Even if the lifters were fully compressed the vavle still open. So I cant see it beingoil pressure related. The lifters will drain if the upper deck non-return valves are sticking open a little, but this only creates a rattle until the lifters bleed. The lifters drain a little oil in operation to lubricate the cam journals and also will bleed off underneath. These a fairly large drains back to the sumps. If the lifters fo some strange reason are blocked and can not dump oil, they will overfill and cause the valves to hit the pistons, very very unlikely this has happened. Why it has zero compression on 4 cylinders s odd to say the least. It is pretty unlikey that you have had debirs fall into to 4 different cylinders and lodge under the valves, but I guess it could happen. The intake valves wear quite fast on a vg, and are more than likely no sealing 100% anyway, but to have 0 compression indicates a sizeable leak. This is confirmed by the amount of reversion you had back out of the intake. For it to drive in ok, and then do this after a simple plenum pull is very odd. Remove the cams and pessurize the cylinders again. If the valves a still leaking there is only one option left.
yours will be fine mate it's just one of those freak things 1 in a million that just happened to mine..
wow this is so interesting to listen to! i had mine off for 3 months and not a single issue... this is insane o connor.. and no one has access to the garage its stored in to tamper with it??
only my workers had access but i am here before they get in and here after they leave can't see it being one of them... will try a few things today if nothing works heads will be off tomorrow.. will update on what i find..
Ensure you do a pressure down test once all four camshafts have been removed, this is the only way of eliminating valve lifter problems. Cant believe that you have four cylinders with zero compression without there being some bent valves Good luck
throught id try compression after trying the diesel trick now i have 0 compression on all cylinders ????? Any idea's
Sorry mate, phone service is playing up and I never got yor SMS till this morning. zero compression again ....... changed from oil to diesel wash then back to oil and we loose the 2 cylinders again the only alteration as been the oil much diesel wash or new oil in the rocker covers ?????? this would show oil is making the cams and lifters Have you fitted a tempory mechanicle oil pressure guage..... dont trust the electrical guage on the dash Here's what I'd do next..... grab an old spark plug and gut the ceramics out so all you have left is the bit that screws into the head. add a length of small diameter pipe to the threaded part of the plug, (this pipe needs to be long enough to reach down into the sparkplug cavity and be proud enough of the head for you to screw it into place....10 inches should do), then add an airline connector to the pipe so you can directly hook the airline to the pipe/plug setup 1/2 inch pipe should do the trick and you can weld it easily enough with the stick, the brass airline connector will need either a bronze job or silversolder to weld it to the other end of the pipe unless you have a steel connector for your airline setup. crank back the air compressors regulator so you have LESS than 15psi of flow connect airline to your new bling and super trick sparkplug gadget and check each cylinder Where's the air going ? down the exhaust ? up through the lower plenum ? NB: dont forget to wind the motor over by hand so each cylinder is at TDC when you "pressurise" it for the test If the inlet valves are bent the air should only be comming up through the lower plenum, cant posiably have bent the exhaust valves too as they are'nt accessiable like the inlet ones..... you may need a plate to screw down onto the plenum to block off each port and re-test again with the air to check that the leak is or isnt just the inlet valves .. If the air is leaking ONLY up through the inlet side then you must have bent valves if its leaking out the exhaust and inlet ......or the exhaust only then its got to be another issue thats causing it. Did you ease the bearing cap bolts on one camshaft so it could rise up slightly to see if the valves closed up without any camshaft pressure on them ??? Again..... if the valves dont then close its because they are bent I'll be in a shyte reception area again for the first half of today, should be back in "reception" by 2ish this arvo..... Thanks Telstra :F: Kingy
Today loosened off the cam shaft bolts retightened then used compresser to blow air in spark plug holes now all the valves are sealing again, did compression test and i have 30psi in each cylinder
good warning about earths on plenum but when i took the plenum off i disconnect ecu and ptu everytime. At the moment i'm looking at a mechanical fault not electronic Seems all valves are now sealing but very low compression still.... I have a whole tt engine here to take parts off but want to see if i can fix this motor and try and find what caused it, i know thats probably just a dream though..
I gather you did this in your workshop, what kind of workshop is it? Is there any chance of there having been some interesting kind of dust in the air at the wrong time which mixed really badly with the oil on and around the cams while you had the cam covers off and your problems started there?
