camshaft and followers
Discussion
Hu guys, as per the title, my car has done 65k miles and there was a definite tappety sound from the offside bank.
There was no power loss, the car pulled like a train, just this annoying tappet sound, which seemed to be quite local.
I am in the process of stripping all the ancillaries off the engine, as i had intended to remove it and change the cam on the bench.
My question is ....can a cam follower/followers be problematic, as i have removed the rocker shafts and followers and inspected them for signs of wear.....and there seems to be none.
I am no expert on this, but i have been reading some of the relevant pages on the RPI website and i have been using this as a reference.
http://www.v8engines.com/engine-4.htm#worncams
They are all flat, none of them are scored or dished in any way, and even the cam, as inspected as best as possible from the valley looks in great condition.
the cam has no worn lobes or brown staining etc or any of the usual signs of uneven wear.
So can a follower leak down, or similar, so as to be noisy.
Is there a way of checking the cam and followers as it is, i.e can the lift on each lobe be measured in some way to check for camshaft wear?
Is it worth just changing the followers or should i carry on and remove the engine and change the cam, followers and timing gear.
Any help or pointers appreciated.
There was no power loss, the car pulled like a train, just this annoying tappet sound, which seemed to be quite local.
I am in the process of stripping all the ancillaries off the engine, as i had intended to remove it and change the cam on the bench.
My question is ....can a cam follower/followers be problematic, as i have removed the rocker shafts and followers and inspected them for signs of wear.....and there seems to be none.
I am no expert on this, but i have been reading some of the relevant pages on the RPI website and i have been using this as a reference.
http://www.v8engines.com/engine-4.htm#worncams
They are all flat, none of them are scored or dished in any way, and even the cam, as inspected as best as possible from the valley looks in great condition.
the cam has no worn lobes or brown staining etc or any of the usual signs of uneven wear.
So can a follower leak down, or similar, so as to be noisy.
Is there a way of checking the cam and followers as it is, i.e can the lift on each lobe be measured in some way to check for camshaft wear?
Is it worth just changing the followers or should i carry on and remove the engine and change the cam, followers and timing gear.
Any help or pointers appreciated.
J400GED said:
You say a "tappety" sound, does it manifest itself under certain conditions? e.g. engine temp and load.
Its very obvious with the bonnet open and the engine at idle, i dont notice it "on the move" While i have been stripping the engine, i removed both exhaust manifolds, and there was no obvious signs of leakage, so not the usual noise that a leak from one of these can create.
TJC46 said:
Its very obvious with the bonnet open and the engine at idle, i dont notice it "on the move"
While i have been stripping the engine, i removed both exhaust manifolds, and there was no obvious signs of leakage, so not the usual noise that a leak from one of these can create.
Sorry if the following are egg sucking questions but I haven't much deatail to go on:While i have been stripping the engine, i removed both exhaust manifolds, and there was no obvious signs of leakage, so not the usual noise that a leak from one of these can create.
Did you narrow down the location of the noise? e.g. towards the front of the engine, rear or middle?
Have you done any leak test on the manifold/s since you have removed it? It is possible for it/them to leak in the middle of the 4-into-1 area so you wouldn't necessarily be able to see a sign of a leak with the naked eye.
They can also leak around a gaskets without necessarily showing.
Assuming the pads are all intact and attached to the rockers, I'd be looking at preloads (a clearance where there shouldn't be one will clack), and at valve springs. There's sod all to the lifters so I'd not be expecting problems although it's dead easy to pull them apart if the valley is open. Not generally thought a good idea to renew lifters alone but I'm sure many will have done it without issues
Took the engine out and stripped it down to remove the cam.
Took the camshaft into work and had all the lobes measured with a micrometer.
Results are as follows, starting from the front [timing chain end]
NO.1 - 34.75MM ---- NO.9 - 32.55MM
NO.2 -34.71MM ---- NO.10 -34.71MM
NO.3 -34.72MM ---- NO.11 -34.25MM
NO.4 -34.74MM ---- NO.12 -34.25MM
NO.5 -34.74MM ---- NO.13 -34.71MM
NO.6 -34.71MM ---- NO.14 -34.71MM
NO.7 -34.33MM ----- NO.15 -34.75MM
NO.8 -33.25MM ---- NO.16 -34.75MM
No. 8 and 9 well down, so its new cam time i think.
Opinions welcome and appreciated.
Average size is 34.74, lowest is 32.55, so what in thou's of an inch is 2.19mm
Took the camshaft into work and had all the lobes measured with a micrometer.
Results are as follows, starting from the front [timing chain end]
NO.1 - 34.75MM ---- NO.9 - 32.55MM
NO.2 -34.71MM ---- NO.10 -34.71MM
NO.3 -34.72MM ---- NO.11 -34.25MM
NO.4 -34.74MM ---- NO.12 -34.25MM
NO.5 -34.74MM ---- NO.13 -34.71MM
NO.6 -34.71MM ---- NO.14 -34.71MM
NO.7 -34.33MM ----- NO.15 -34.75MM
NO.8 -33.25MM ---- NO.16 -34.75MM
No. 8 and 9 well down, so its new cam time i think.
Opinions welcome and appreciated.
Average size is 34.74, lowest is 32.55, so what in thou's of an inch is 2.19mm
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