Yeah, I guess it's not like you are cutting up things that are going to fill the air with harsh abrasive dust or anything. Oh well, it was a thought. This is rather a fascinating one isn't it? Though I guess probably somewhat less so for you being your own car and all.
Yes it has all been a wierd fault, it's not my daily so i'm not to stressed without it...Just want to find out why it happened , i dont care if i've killed the motor just want to know why???
Yeah, I understand completely a broken car is a hassle, a broken car when you have no idea why it's broken is really damn frustrating.
i loosened cam bolts as i did heard a sucking or air escaping noise then retightned each one then cranked it over and the intake valves are all closing and got 30psi of compression on each cylinder..but considering i dont have much compression wondering if i should do the exuast valves now??? QUESTION what torque should the valve bolts be tightned to ?
Cheers Mate so should i now loosen the exaust cams and then retighten, since it has helped the intake valves to close fully ??? is there a way to test if the exaust valves are not closing??? trying to get hold of a leak down tester at the moment the local autopro didn't even know what it was lol...
Sorry, you've exceeded my level on knowledge but if you've got the plenum off, why not loosen the exhaust cams. Will only cost a little time and silicon.
What sort of silicon do i use i did a search and people have got silicon from nissan is there one i could use from repco or alike ? or a part number from nissan
For the exhaust cam covers I don't think there is a gasket. Just use goo, ultracopper or some such. (I think, may be better to wait til someone wiser than me confirms)
Had a bit of a think........ What I'm going to suggest is somewhat odd so bear with me here...... ( in fact I've only ever encountered it twice in all my years of playing with cars so its rare..... nope change that PHARKEN RARE !!! ) first up put 5 sparkplugs back in the motor, leaving cylinder number 1 without a plug next take a small square of paper about 3~4 inches in size and screw it into a tight ball...... just so it slighly larger than the sparkplug hole grab a long screwdriver and drop the paper ball down into the sparkplug cavity, now with the screwdriver push the paper ball into the plug hole being carefull NOT to push it into the cylinder. (What were trying to do is place a "pop gun cork" into the barrel..... the paper ball is the cork and the sparkplug's threaded hole is the barrel ) make sure the paper ball is in there with a good firm fit.... ( hence the screwdriver to push it in ) Now crank the engine over in short bursts..... ( the reason for the addition of the other plugs is to SLOW DOWN the cranking speed ) there should be a "POP" sound when the paper ball is fired from the plug hole ( with 150+psi of compression, you'll never find the paper ball after its been popped out !!! ) THE INSTANT YOU HEAR THE POP STOP CRANKING IMMEDIATELY The paper ball WILL ONLY be fired from the cylinder on TDC on the compression stroke, it will remain in place during the intake / and exhaust strokes. Now place a wooden dowel down the sparkplug hole untill it sits on the top of the piston...... move the engines crank fowards / backwards as required so number 1 cylinder's piston is at TDC...... you should only need to move the crank a few degrees untill the piston is right at the top of its stroke. THIS IS TRUE TDC :zlove: now for the interesting bit....... check the camshaft drive belts timing mark alignment If the timing is spot on then ALL the marks should line up 100% with the pistons position If the camshaft timing marks DONT line up with the piston at TDC then ladies and gentlemen this will be the 3rd time I've ever seen this happen 1st occassion: V8 holden motor the key in the crank shaft that locates the bottom camshaft sprocket had sheered, the timing had then moved slightly but had not damaged any valves, this engine also had low compression, then some compression the zero compression.......... I only found this when I manually tried to move the crank and watch the valves movement, it took nearly 20degrees of movement on the crank for the valves to start moving, as it was I was moving the engine backwards and if I'd have be turning it fowards I' wouldnt have seen the 'lash' in the timing 2nd occasion: Toyota troop carrier petrol engine Exact same symptons as the holden motor..... varying compression, only this time the "plastic gear" on the camshaft sprocket had sheered away from the alloy drive ring Yep TOYOTA glue a plastic gear to an alloy plate and call it a drive gear :W: the engine was ok valves wise but the timing was out by 30degrees at the most and came back to almost std on other tests I ran What I'm thinking here is that the belt has "skipped" a few teeth on the CRANK DRIVE ( you have said that the belt marks were all good in past posts & they may well be perfectly spoton in relation to the gears....... provided that the crank gear is lined up with the number 1 piston 2 things may of happened...... pick one..... 1/ the gearset on the crank may have moved -> see the V8 holden story 2/ the belt may have jumped a few teeth at the cranks gearset, what may have happened is something was accidentlly dropped down there ( you have exposed drive belts ).... a small bolt, ciggarette lighter , socket, rag..... posiabilities are endless I've seen drive belts stretch out enough for a ROSSI boot to go through the drive and the belt still continue on ( had a harley with a 3" exposed drive belt....... bad idea, but looks so kewl) If something was dropped down there then the gearset would have grabbed it and sent through with the belt, this would mean ( depending on the objects size) that 1 ~ 10 teeth could have been "jumped".... giving you low compression / zero compression / ....... all would depend on how many teeth were jumped AND if the object was still being taken through the gearset. I'm betting right now all your timing marks line up on the cams and the cranks gearset I'll also bet that number 1 piston is NOT at TDC when its should be if my theory is right that is Oh.... what gave me the idea you ask after adding the compressed air to the cylinders you got all cylinders up to 30psi, the air must have moved the piston back down the bore slightly yet left the valve train in the same spot.... you then did a compression test and got compression...... compression has again altered ( back down to 15psi ) so the valve timing must have moved in-relation to the pistons position.... Kingy
once you bear with the post it has some validity . I jumped 4 teeth on crank gear due to a failed tensioner and 2 teeth on both intake and exhaust passenger cams. Started, but it was hard, compression changed between cycles, ran rich as f*** and bad pinging on low rpm. The other way to check the belt is to remove the lower timing cover and rotate the motor by hand until the marks line up on the cam gears. Check the markings on the crank sprocket and on the cam gears.
Thought I better add this..... the paper ball excersize WILL GIVE you TDC every time....... I've seen too many cases where engines have been badly diagnosied due to timing being out 180 degrees. any fool can drop a screwdriver down the hole and feel the piston at the top..... but is it the firing ( compression stroke) or the exhaust stroke ???? hence the paper ball....... it never lies sorry guys ..... old farts secrets have to be made somewhat public on the odd occasion Kingy
its the only thing I can come up with that covers ALL the things that have been listed as symptons other than that I'm totally out of ideas as to what else it could be..... Here's hopeing Kingy
ladies and gentlemen....... we have a winner Phonecall from Bryan last night ...... 7 teeth jumped at the crank, lots of bits of munched up plastic around the crank drive including bits with "teeth marks" Hopefully a re-alignment of the belt will see no valve damage Kingy
yeah at least i found the fault i'm happy with that much,, next little probelm and im hoping is only a small problem is that. in the tech section on timing belt removal you put a 10mm screw through the tensioner unused bolt hole to push the tension off to et belt off well i've found mine does not have that screw hole and all its cleanly broken off the cast ???? Do i need that cast there apart from using it to remove the belt ?
