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Chrysler Repair/99 Chrysler 300m: tappet noise


Dear Roland
I have a knock in my engine it seems coming from one valve, engine is very stable idle, economic fuel.
My question :
This engine has hydronic valve control or not, if yes is there som oil additive can solve this, if no can I found some thing need adjust (my be rocker gab )
Thank you,,

Hi Essam,
Which engine do you have: 2.7. 3.2 or 3.5L?
There are some oil additives that claim to dissolve sludge that may be blocking oil to reaching one of the valve lifters which then causes there to be too big a space between the valve that rocker and thus the click occurs. You could try such a product soon before you are planning to change oil, then change the oil. But thare are about 10 other reasons for tappet noise:
too high or too low amount of oil in the crankcase, thin or diluted oil, thick oil, low oil pressure, dirt in lash adjuster, worn rocker arm, worn adjuster, worn valve guide, excessive runout of valve seat or valve face, missing adjuster pivot. You can remove the valve covers and push down on the rocker arms one at a time to find the 'spongy' adjuster and then focus in on that one.
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Roland Finston


Free fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question, briefly unavailable, or asleep overnight, so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2011 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.


Five decades as a 'do-it-yourselfer' on domestic and imported cars.

Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Advanced degrees in Physics/bruised knuckles

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"Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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