Loud off and on tick

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Tammaru

Well-known member
Oct 19, 2007
164
0
New Jersey
So i have an on and off again loud tick on my 97 discovery. It never kicks in until it is warm, driving
More10 miles an hour it goes away. If i stop at a light and leave it in gear it is very audible, if i put it in park, it goes away. Then again, other times i drive and there is no noise whatsoever, other times very loud!

So far i have replaced lifters, rods, springs, had a valvejob (along with headgaskets and new heads etc) replaced the oil pump, replaced the rod bearings and the main crank bearings..... What am i missing?!? What the hell is this tick! Thanks!

Tarmo
 
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discostew

Well-known member
Sep 14, 2010
7,735
1,026
Northern Illinois
Since you say you have new lifters and an oil pump I guess it could be the steel insert in one of your rocker arms. It's the cup that the pushrod rests in. I would still want to know what kind of oil pressure it's got. Another possibility would be a cracked flex plate.
 
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Tammaru

Well-known member
Oct 19, 2007
164
0
New Jersey
lol... thanks guys, ugh, things to looks at after I've gotten everything back together. Any chance this could be a worn Cam? What kind of noise does that make? Loose piston sleeve? is that a possibility?
 
CPTLOU

CPTLOU

Well-known member
Jul 30, 2013
62
0
Sunny San Mateo, California
Weird on a DI. Never had them with engine ticks. Had many many...

Having owned and sold over 40 DIIs, I would bet money it woulds a cyl. sleeve. One reason why I sold my last 04' and went back to an 02' with a 4.0L. The thing is, it could last like that for years, or it could go out suddenly. But on a DI it's unusual. Hopefully I am wrong.
The last 04' I had with the same chatter was purchased by me after the owner had dumped over $3K in new cams, lifters and an oil pump ( what they sold him on at an "independent LR place in the Bay area who shall remain nameless", oui ).

My fix ? had the engine swapped with another used4.6L for $2.5K OTD. End of problem.

When the block heats up ( as aluminium does), it sometimes will "squeeze" ( obviously not something the naked eye would see) the cylinder sleeve out of place.
If you've read up on 4.6L motors, you know that they have a propensity to overheat; the end result is to cook the sealer at the bottom of the sleeve, weakening it and sometimes leading to one detaching and "walking".Hence the random noise. Almost always once it warms up.

Hope it's something trivial like someone suggested, such as perhaps a broken / loos nut floating down there somewhere or a loose bolt that wiggles and unwiggles itself as you drive and the car gets jarred and shaken about.
 
mbrummal

mbrummal

Well-known member
Jan 23, 2009
2,894
22
Willow Spring, NC
CPTLOU said:
When the block heats up ( as aluminium does), it sometimes will "squeeze" ( obviously not something the naked eye would see) the cylinder sleeve out of place.
If you've read up on 4.6L motors, you know that they have a propensity to overheat; the end result is to cook the sealer at the bottom of the sleeve, weakening it and sometimes leading to one detaching and "walking".Hence the random noise. Almost always once it warms up.
Click to expand...
Lol, not quite.
 
WaltNYC

WaltNYC

Well-known member
Mar 3, 2010
710
138
NYC
Sure it is a tick inside the engine? Could be an exhaust leak near the manifold. Stick a rag briefly into the exhaust to see if it changes the sound.

Also had a situation where a spark plug was not fully screwed in and had a super small compression leak with sounded like a tick.

Just wild guesses. Seems like you've check a lot of the other boxes already.
 
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Tammaru

Well-known member
Oct 19, 2007
164
0
New Jersey
It's def in the engine.... if you go underneath by the oil pan it is much much louder.... the ticking usually kicks in when the engine is warm, I would think that the exhaust would expand and the tick would get quieter as the engine got warmer.

I'm going to take the pan off and check all the bearings again, re-torque and make sure everything is correct... I will post what happens.... thanks for the help so far guys!
 
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Tammaru

Well-known member
Oct 19, 2007
164
0
New Jersey
eh, went through and retorqued everything, tick is still there... Never when the engine is cold and only at idle. Very frustrating.
 
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