hydraulic lifter question
hey there everyone, just wanting to know if a dodgy lifter would cause a misfire in the engine?
the holden mechanic
yeh it can, would have to be very sticky to do it tho.... what else ahve u checked???
well i have replaced, crank angle sensor, dfi module, coil pakc, plugs, leads, new injectors, cleaned the fuel rail, coolant sensor.
and there is a kind loud tapping on the number six cylinder, and it is missing, so i am confused, thats why i asked, if there is anything else you can think of it would be well appreciated if you could share them
cheers, nick
the holden mechanic
checked the valve clearances????
na not yet, can you explain how? and what are the measurements? and if the clearances are not right do i just need to put new lifters in it?
vyma100
455rwhp LS3
Hydraulic lifters dont run clearances. Remove the rocker cover over the noisy bank. Turn the engine over & see if any of the rockers come loose.
Remove all spark plugs and do a compression test of each cylinder both dry and wet.( If the compression is low in the test dry and then you add a little bit of oil into the cylinder the figure gets a lot higher, it means leaking around the rings ,and is time for a ring job.)If the compression still stays low with oil , the problem is in the valve area.
Then remove rocker cover and make sure everything is intact, if everything looks fine, no broken arms, springs etc you have to remove the heads and then you can see if you have a damaged valve etc,
Could be a burnt or broken valve, broken valve spring, broken rings in that cylinder and as you said a damaged lifter.
Compression testing is a good way to work out the engine condition, the testers are fairly cheap from auto shops.
You said you have already checked all electrical side and is fine , so the only other areas giving a miss would be the valve area or the injectors, did you check that the injector is firing ok? You can listen with a screwdriver to the ear and touching the injector to see if it clacking. It may make a noise but be blocked so if you remove the lead from injector and nothing happens to the speed or noise of the engine , you could always try swapping an injector over and see if the miss has now moved to that cylinder you moved the injector to.
well i did move injectors all around and it still noisy from number 6, but i will do a compression test soon, its just tapping real bad on that cylinder, and i bought the car off some hoons, so im thinking they revved the crap out of it and not letting enough oil to the lifters so they run dry, thats what i was thinking, but yeah it could be the valves and heaps of other things, wil check it on my lunch break at work.
Go Hard or Go Home
The early VN's did have a nasty habit of wearing off the case hardening on the camshaft and wearing the lobes down, which allowed the lifters to not open the valves correctly thereby causing a missfire to occur. Not only would I do a compression test but I would also do a vacum test as this will also assist in testing a vehicles operation,as the incorrect amount of vacum will cause the vehicle to run lean as it is not sucking in the right amount of fuel to burn correctly.
well i have a vacuum gauge in my car set up, i am also going to replace inlet manifold gaskets and rocker cover gaskets, so while i have them off is there anything else i can check.
I posted up a how to read vacuum gauge readings somewhere, I'll dig it out and add to this post.Originally Posted by potshots007
Can't find the original, but this link shows you a lot about reading a gauge.
http://users.bigpond.net.au/ergoff/vac1.htm
yeah that gauge reading thing is awesome
only problem is mine is telling me it has zero vacuum on idle, so what can anyone tell me about this? where is it leaking?
It depends where you have the vacuum hooked up to.
Assuming the gauge is working and the hose isn't blocked it should show something.
You want an area that's around the manifold, if you remove the hose from the spot it's on you should feel sucking. I hooked mine up to a T piece around the fuel regulator. Be careful if you use the ones on the throttle body, I think one of them went to a point before the throttle , and you won't see any vacuum.
You could also T off the bit where the MAP sensor hooks up to the manifold.
just to let you know, you can find these engines for about 300-1000 in very good nick, i too was buying shitloads of stuff to solve a problem and i reckon i spent on parts what i could of bought a good second hand motor with, but other than that good luck dude
Physics Geek
That link to the Vac Gauge page is AWESOME! I actually book marked it.
A good spot to hook the vac gauge in is on the hose running from the t/b to the vac ball, make sure that the gauge goes on the t/b side of the little valve in there, otherwise it won't read properly. Works a treat on mine.
Gravity is proof that nature keeps getting us down.
can anyone show me a pic of where it should be hooked up?
It's not that critical , just not to the ports on the TB.
The one mouce said , just follow the hose from the ball under the left guard through the engine bay and see where it hooks up to the manifold.
You could do it at the MAP sensor too, but I didn't want to mess with something that is so critical, it doesn't take much to thow the MAP out so thought maybe a loss of vacuum here might not be so good.
This is where mine is hooked up, you just need a T piece and some hose.
awseom, will change it tonight, thanks everyone
well i changed the vacuum gauge and its sitting at about 21 inch/mercury, which is said to be normal. so now i ask everyone again, its tapping real bad, how can i find out if it is the lifter making noise? how hard is it to get the lifters out? where abouts do i get lifters from?
cheers, everyone
A fairly big job.
The cylinder heads, manifold etc have to come off.
You'll need a VRS gasket kit , which will have head gaskets, manifold gasket , valve stem oil seals etc.
The engine doesn't have to come out , but be prepared to spend a fair bit of time bent over the engine bay, if you're young it won't bother you too much.
If you're going to do it yourself, besides the usual tools, sockets etc, you will need to change the oil and filter after it is all done , because you can't help crap getting in the engine. Once the manifold and heads are off the lifters will be obvious.
If you start pulling things apart keep them numbered, for example get a piece of cardboard and poke the valves into it and number where it came from.
I usually do this with pushrods and rocker arms too, but that's not as important.
The valve stem oil seals stop oil dropping down the side of the valve stem .
It is important that you change them as they get brittle with age, and they are what causes smoking at idle.
Get some wire brushes , rotary one for a drill to help clean out the head.
A bench mounted wire wheel is good for cleaning valves once removed.
Price a gasket kit set , lifters etc at your local spare parts place , have a think if you can do this yourself, then get a price from a reputable mechanic and if you don't feel confident doing it yourself it might be best to pay for the job.
It's not terribly difficult, but if you have no mechanical experience and can spend your time better earning money rather than fixing it yourself , sometimes it's better to just pay for it.
Eg if you are a computer technician and can earn $100/h why waste a day DIY when you would only pay a mechanic half of what you earned in that day DIY.
And if you don't already have a workshop manual , add that to the cost.
Most important thing is to keep a clear head and make a mental note of where things came off from, the lengths of bolts , wire harnesses etc.
You'd be surprised how many people pull things apart then spend the next 2 days trying to work out where all those parts came from
yeah cheers, man, im a first year apprentice mechanic so if i get stuck i can just take it to work, but i just thought because of the long weekend i might pull it apart and have a bit of a look, will get the gasket kit through work, i know most things but there is no harm in getting more help which is why i use this forum as its awesome.
cheers again, will tell you how i go, when i get to it
Sorry , I didn't know what your level of knowledge was, I tend to assume people know a little bit so I over explain
If you're failrly sure the noise is coming from a lifter and you have a fair idea what bank it is , the next thing you should probably do is remove a rocker cover and have a good look/listen. You can use a piece of garden hose to your ear like a stethoscope with engine idling, but things will get a bit messy , but you already like being covered in oil
One trick I was told ages ago with hydraulic lifters is to bang on the rocker with a soft faced mallet over the pushrod, if the noise goes away you know it is a leaky lifter. You'd have acces to leak down testers at tech or work if you want to check them out, but remember we're dealing with 18 year old cars , so there's a good chance that all the lifters are in a similar position anyway, and a new set wouldnt be that dear. Sometimes GMH surprise me with their prices and are as cheap if not lower than repcos etc, so price genuine and through a engine parts place.
I don't usually ask at supercheap for engine bits etc, because a lot of them don't have experienced parts men.
I,m trying to move up a notch in my model so if I've helped please click my scales ........ Yes !! I,m a rating whore
awesome again, but yeah i was thinking bout changing them all, is there a way to change the lifters without removing the heads? like just pull a rocker cover off and take the inlet manifold off and undo the rockers the pull the push rods out etc?
Aussie Muscle Fan
I don't think You need to remove the heads to do rockers or lifters, just the rocker cover, maybe the inlet manifold if you want some more room to work with.
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote