Hi all, I have a LA360 sb that I've noticed has become quite noisy. It's not really a knocking that sounds heavy, but more of a tick tick. My question is, I started pulling plug leads one at a time to see if I could find the offender and have found the noise stops when I pull one of the plug leads off. Does this mean it's definitely the bottom of the motor with the problem, or could it be lifters, or something else?
Cheers guys
strobo,
Jul 17, 9:52pm
Free tip . Give it a dose of pro-ma mbl (metal base lube ) in with the engine oil .If the noise is still there after a 30 minute run then there is a high probability that something more mechanical is worn that needs replacing . Suggest also use a hearing aid . stethoscope or a long screw driver up at your ear hole listen starting from the cylinder heads & .work your way down ,mid block section, front engine then finally the sump pan . You should be able to 100 % pin point where the noise is coming from this way. Deduct which if either gudgeon pin ,piston,lifters,big end, or top end on the cylinder that area you suspect.
intrade,
Jul 18, 6:06am
post 2 has good information because proma is used to quiet lifters on mitsubishi , if you dont know what the noise is because if its bottom end then its going to be expensive , it could of course also be early ignition on this pot somhow if you have a own ignition coil dedicated only to fire that pot due to all sorts of reasons like carbon tracking ,analysing the ignistion wave pattern with a good oscilloscope would rule that one in or out befor replacing parts who are not broken.
intrade,
Jul 18, 6:18am
i had last week a 1980s toyota in my shop problem was lack of power and he never ever had changed the fuel filter . rite so i open the bonnet and say you got fuel injection that filter is likely blocked up if you never ever have changed it. So i changed the filter i had 1 on my shelf for his car then went for a test drive drove better then before he said and then i said yes but it dont runs on all 6 cilinders . so out comes my pico scope relative compression test all checked fine non below 90% compression then i put it on the coil to see if the coil is fiering good all the time. tick box the coil serves all 6 pots = fine so we move on to the ignition wires to look at wave form of burn time of spark plugs just looking if all look the same to start off with 1 is ok 2 hmm that dont look right, 2 not ok? moved 3,4,5,6 all rest look like pot 1 , so i says pull number 2 sparkplug i want to see that plug now. once it is extracted the thing is complete white and the bend part on the sparkplug was non existent it had melted from the plug. i sayd dude this plug is extreemly wrong its way to hot your lucky you did not melt a hole in the piston so far. told him get all new plugs , said they struggled to get these ones as everyone told him these are the plugs acording to his 1980s ownership document. i say i tell you they are the wrong plugs where are the old ones? he said he got them at home still, i said buy the plugs that where in the engine them are the right plugs . last i hear he got new plugs and all is fine . probably wont see him again for another 20 years since its a old bullet proof toyota.
intrade,
Jul 18, 6:34am
so you can see adding promar mL-8 i think its called will quieten the lifters if it is these mitsubishi apperantly sell this as oem additive. this is the cheapest option to try and it wont harm to add this even if it is not the lifters . if that dont work then i be scoping things out with a pico automotive scope or other expensive scope and know how what to look for you can also look at the plug what it looks like compaired to the plug next to it if you got no scope since you already think you know what pot has the problem. it can also be a companion cilinder with problem . system design is what you need to know more and more to make guesses what to test next.
normal and high speed glazing look the same i would call both as normal as you wont be able to guess what it will be by looking at your plugs also i dont know what car you have or what airoplane as there is no LA360 car acording to the internet its why you sould always give all details . i go drive my MM03 now
boss_hogg,
Jul 18, 8:05am
thanks for the tip guys, it's an old motor intrade :-)
that still dont helps this engines have had it all is it this? In 1996, as Dodge moved to the JTEC powertrain computer, the LA engine series gained OBD II on-board diagnostics, and EGR was dropped (late in the year for the 360). if its got obd2 then you can look what the fueltrim is doing you need to supply all information if you want propper help.
boss_hogg,
Jul 18, 8:16am
Sorry, I don't know it's exact age as it's not the original motor. I'm guessing it was born around 1977. There's no ecu.
intrade,
Jul 18, 8:34am
ok remove the spark plug and look at it , then move the piston up and put a drinking straw in the hole so you can see the straw move up and down when you move the crank shaft move shaft a centimeter clock wise then 1 cm anti clockwise continue this with the distance of crank shaft less and less milimeter clock and anticlock untill you dont have the straw or screwdriver not move any more. i said drinking straw as you dont want a screwdriver jamming in the piston and engine, also battery must be disconnected so it cant possible start on its own somhow .
once you established the play you have on your suspect cilinder , you check the piston next to it if it seems to have less play . normally there should be 0 noticable play screwdriver should move within half a millimeter of crank movement backwards forward clock-anticlockwise. if you got play you found bearing or piston pin play compairing it to the other cilinder is the proof test.
boss_hogg,
Jul 18, 8:42am
Thanks intrade, will have a look later on today. Will get back to you with what I find. Cheers
kazbanz,
Jul 18, 8:51am
boss hogg--I would suggest you swap plug leads from one cylinder to another and see if the issue stays put or transfers to the other cylinder. --I suspect a dud plug lead. You will be amazed how much noise a HT lead arc can make
strobo,
Jul 18, 3:09pm
I think the idea is to use the proma as a diagnostic tool rather than a fix it for OPs case! Another free tip .Keep a bottle handy in ya tool box ;-) ps keep that drinking straw handy too!
extrayda,
Jul 18, 7:51pm
I would have thought it would start to have a noticeable miss if that was the case? No harm trying though - remember to swap both the spark plug AND dizzy end or you will have some other surprises :-)
Personally I would try Kaz's suggestion (cos it's very easy to do), if no change, pull the plug and look at the condition, then maybe pull the rocker cover for that side and have a look at the valve stems / springs / pushrod / rockers for that cylinder. Although in theory those will all be moving pretty much the same whether or not the plug is firing.
extrayda,
Jul 18, 7:53pm
The other thing it could be (if tick tick rather than knock) is a leak in the exhaust gasket on that specific pipe. If there is one, you should either be able to feel it, or possibly see some black soot / smudging under / over that pipe. Is the motor running fine apart from the noise?
extrayda,
Jul 18, 7:57pm
Another easy check for HT lead arcing is to run the motor at night - at which point you would probably be able to see it.
boss_hogg,
Jul 19, 7:17pm
Hi again guys, thanks for all the help and advice. I haven't had much time to have a proper look at things, but while I was swapping the HT leads around (thanks kazbanz) I noticed a little bit of exhaust gasket sticking out between the headers and the head. I had a quick feel for a leak and did feel a wee draught. Managed to burn the back of my hand in the process. Fingers crossed this is the problem. Thanks again team. :-)
intrade,
Jul 19, 7:43pm
you mean a intake gasket leak?
skull,
Jul 19, 8:06pm
Intake don't has headers intrade, it's the exhaust manifold gasket leaking giving the ticking noise. Remove the plug lead, it don'ts fire so it don'ts tick.
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