Fossicker
I know most of you guys drive diesel engine Discos over there, but regardless one of you may have come across this. He rebuilt his 4.0 V8 almost entirely and everything is new. Did have a couple of issues with a loose bolt in a cylinder and another with the oil pump. He replaced rod, bearing and piston on that one, replaced front cover and pump gears entirely on the other. Checked Piston and valve clearance after rebuilding from the accident, all bolts torqued to spec, replaced cylinder heads, etc. Compression is upper 190's - lower 200's on all cylinders. He ended up with a pretty loud tick that has come and gone a couple of times. Its loud and the noise does not go away when the leads are removed cylinder to cylinder. Please check the video clip and post suggestions.
[ame]https://www.youtube.com/watch?v=cwJSKvdtnyo&feature=youtu.be[/ame]
Swaggie
Faulty/ collapsed cam follower, rocker arm pushrod insert/s worn, were the followers replaced with genuine ones or generic GM ones? The other issue that can arrise after machining deck heights and cylinder heads is that lifter clearances become too tight . Have a read https://www.google.com.au/url'sa=t&s...97D6vqVO8gixkQ
The Isuzu 110. Solid and as dependable as a rock, coming soon with auto box😊
The Range Rover L322 4.4.TTDV8 ....probably won't bother with the remap..😈
Fossicker
Originally Posted by justinc
thank you! I will relay the info and wait for a response.
Fossicker
since the Disco doesn't have adjustable lifters, were you thinking that the clearances are too far off with the upgraded cam? I didn't mention that. he isn't using a stock camshaft. but the springs and rocker assembly, pushrods, lifters are all OEM I believe. Since it is non-adjustable, how would one go about searching for the issue in the valvetrain, and the fix, if found?
Swaggie
With an increase in lobe lift then DEFINITELY have to check lifter preloads!!! There are shim kits available to fit under the rocker shaft pedastals.
Jc
The Isuzu 110. Solid and as dependable as a rock, coming soon with auto box😊
The Range Rover L322 4.4.TTDV8 ....probably won't bother with the remap..😈
The MOD Father
Justin! did you notice the top rad hose??
"How long since you've visited The Good Oil?"
'93 V8 Rossi
'97 to '07. sold.
'01 V8 D2
'06 to 10. written off.
'03 4.6 V8 HSE D2a with Tornado ECM
'10 to '21
'16.5 RRS SDV8
'21 to Infinity and Beyond!
1988 Isuzu Bus. V10 15L NA Diesel
Home is where you park it..
[IMG][/IMG]
Wizard
there are lots better ears listening to this than mine,but i think if it was in the tappets the noise would be there all the time,and a lifter it comes and goes depending on the oil supply.
Swaggie
Thermostat???Justin! did you notice the top rad hose??
😮
Jc
The Isuzu 110. Solid and as dependable as a rock, coming soon with auto box😊
The Range Rover L322 4.4.TTDV8 ....probably won't bother with the remap..😈
Swaggie
SubscriberI wonder if there is a combination of too much lift on the cam maybe tied with not much preload gap causing the collets on one valves or more to hit the valve guide.
Regards Philip A
Wizard
It might help with diagnosis to know if the tapping gets faster with engine revs or not.
It could be something as simple as changing to a different oil thickness or oil pressure.
Or as serious as the piston that was replaced probably came with new rings? If the bore wear had a lip it is possible the new ring broke after making contact with the lip. You might still measure good compression if only the top ring was damaged slightly. (Granted this is less likely as the noise comes and goes)
I'm not a pro but it would be helpful to know if the tapping frequency increases and decreases with RPM.
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