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Knocking upon start up

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Old 08-20-2007, 03:49 PM
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Default Knocking upon start up

The last couple of times I have started my JK the engine knocked for a second or two. Is this normal? I do not drive it very often an I realize if it sits for a while the oil drains to the pan but it just does not seem right for a vehicle with 6,000 miles. I changed the oil at 3,000 miles and I am changing it again this weekend. Checked oil level and that was fine.
Old 08-20-2007, 03:52 PM
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that has happened to me too.
Old 08-20-2007, 04:04 PM
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That would be the sound of the gremlins waking.
Old 08-20-2007, 06:25 PM
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just my observation ...but all vehicles i have driven with horizontal oil filters do this....design flaw...if filter was vertical there is no way for the oil to drain back....the knock you hear is the engine running with no oil pressure....piece of shit design i don't care what anyone says..... anti drainback valves don't work obviously evident by the knocks.
Old 08-20-2007, 06:44 PM
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think i might try this:

http://www.alamomotorsports.com/pmc/Cat_page27.html
Old 03-09-2008, 02:29 PM
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Default anti drainback valves

I had a knock after letting mine sit for a couple days.

If I drive it daily I don't have any knock on startup.

I figured that the filter must have a weak anti drainback valve.

I bought a new quality filter (K&N) and the problem was gone.
Old 03-09-2008, 02:34 PM
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Originally Posted by mslc10
just my observation ...but all vehicles i have driven with horizontal oil filters do this....design flaw...if filter was vertical there is no way for the oil to drain back....the knock you hear is the engine running with no oil pressure....piece of shit design i don't care what anyone says..... anti drainback valves don't work obviously evident by the knocks.
The oil filter doesn't hold all of the oil. There is oil in the pan for the pump to pick up when you start. The filter isn't the problem.

This has happened to a few other folks. Might wanna take it to the dealer.

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Old 03-10-2008, 07:46 AM
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Default Engine knock

I had this problem in my 03 TJ-Dealer tried telling me it was normal so I went out with the salesman and started 10 Jeeps that had been sitting for weeks-no knocking. Engine replaced at 500 miles-got Chrysler to give me the best warranty they have and a months payment if I agreed to keep the jeep and not lemon law it-they also sent a rep out to inspect the work when it was done. Good luck.
Old 03-10-2008, 08:47 AM
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These Moroso engine oil accumulators just might save your engine from damage, by giving you extra oil in reserve. Plumbed into the pressurized side of your oiling system, they use compressed air to force its oil reserve into your engine when the oil pressure drops below normal. When the pressure returns to normal, that reserve oil is forced back into the accumulators, and is ready for the next emergency.



http://store.summitracing.com/partde...5&autoview=sku

This small mod will help keep your engine running for years.

If you wheels often this should be manditory gear for your rig.
Old 03-10-2008, 09:20 AM
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It has happened to me and have found the problem. I thought it was the engine knocking, because that is what it sounded like. However, it is actually loose exhaust manifold bolts. Do a search on this site and you will find a few threads. Have the dealer either tighten or replace the bolts.


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