Sounds like a slipped liner mate.....![]()
Hi Guys,
Just spent $2000 and still have the same noise. What sounds like a Hydraulic lifter that lost it's prime or pressure.
I just put new lifters in it along with all new rockers as they were really badly damaged in the pushrod seats.
The Knock was still there after assembly so off came the sump, all the Big End Caps and the Mains - All worn so I replaced them regardless.
Started her up last night and drove it this morning and it all seemed OK until I came to the first long hill. Then the knock started again, exactly the same as before.
Got it home a switched off.
Restarted the engine and the knock was gone until I blipped the throttle a few times and it all started again, knocking away like blazes on what seems like one Lung, exactly the same as before.
Blipped the throttle a few times to get the revs up to about 3000 RPM and the knock stopped again but it soon returns again if under load or I give it a few quick rev up's.
I get the feeling that I am looking for a fault that is common in the 3.9 litre motors and I am hoping that someone out there has encountered and resolved the problem.
I am totally out of $100 notes and I just don't know where to go next.
All big ends journels were good, even the old lifters seemed like new. The only thing that was really bad was the rocker gear.
Do you think I may have a blocked pushrod or something like that? Maybe a blockage in the Oil Pump? The Oil Light goes out immediately??
Please, if you have an answer, steer me in the right direction, please...
At the point of a mental breakdown guys.
HELP!
Shirley.......
Sounds like a slipped liner mate.....![]()
Slipped Liner? - I am not sure that I like the sound of that??
Firstly are there any ways to test for this problem?
Is it repairable?
Regards,
Now a nervous Shirley......
Hi Shirl
Well, what can i say
It won't be blocked push rods as they are solid metal
Carefull investigation is required from here on, to find the source of the knocking sound
One thing to be clear about is you are not having coolant loss or overheating problems???
First of all ... You need to identify which piston is the culprit
Using a piece of garden hose (900mm long) you have to place it on the rocker cover then down the side of the head near each spark plug to get to where the "noise is loudest"
I fear to answer the problem as being .. The gudgen pin connecting the piston to the conrod
To test this theory...
Take out spark plug
Turn piston over past it's TDC .. so it is on the down stroke
Put slim BLUNT screwdrive through spark plug hole in head & push on piston
If the piston "moves down" .. it may indicate movement in gudgen pin
You may have to repeat this method a few times to rule it out
I know that you have been using a mechanic to fix the problems
what has been his thoughts??? (as he has been listening to it)
Hopefully one of the other highly experienced folks on this site can shed more light on your situation
Mike
Hi Mike,
Gossie had it for about 3 weeks or more and found that the Rockers were stuffed and the big ends and mains were down to copper, so all that was replaced.
No coolant loss, Normal operating temp and except for the intermittent knocking under load, goes like a rocket........
How many Ks has the engine done??
Did you replace the Cam with the Lifters??
Gudgeon pin noise will change between when its hot and cold its also something that I think is not incredibly common with this engine unless its been stroked??
Rover V8s are know for tappet issues if the cam/rockers/chain and lifters have been replaced then move on to the lubrication system (check the oil pressure) if this is ok then slipped liners are a real possibility
Are you having problems with missing coolant??
Have you overheated it??
I too have worn out mains and bigends on these things but have found the valve train to be a more common weak point
Slipped liners are more common on larger engines but it isnt unknown if it has been overheated
I feel your pain the issue here is dont go on a wild goose chase and dont spend more money without knowing facts
Are we talking a knock or a tap???
Im sorry guys there is no OK with a Cam if its tapping and you had reason to replace the lifters unless its done less than 50 000 ks its all bad
Duane
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