When i start my crossfire from cold it knocks (tappet noise) but very loud. This lasts for approximately 1 minute. I use my car every day so it is not stood around for days. My mileage is only 12000 miles and 2 and a half years old. Some lifters have been replaced and were O.K. for 2 weeks. Has anyone else had this problem? I have 4 months warranty left. I have been told that this is normal. Some how I don't think so!!! Please can you help me and let me know. Thank You. Paul Hindle. Bristol. jp.hindle@btinternet.com Or leave a post. Cheers.

 

Must admit I hear mine for a few (5-7)seconds on a cold start but no noise after that.

 

Yes thats normal, its a bit more pronounced in winter as the oil viscosity is more and therefor it takes the pump a few seconds more to circulate oil through the rockers and kill the noise. In summer the oil is thinner and shoots around the engine quicker. Its best not to rev it from start up, let it idle for 30 secs to make sure the engine is fully lubricated before driving off. Prolonged rattling may indicate a fault and wants checking out - it is not neccesary to use a chrysler dealer - take to a Merc dealership, they can diagnose it and do any warranty work.

 

Thank You for the info. Paul Hindle. Bristol.

 

Like Steve UK and Blackrider have said, if the noise only lasts for a few seconds on a cold start up then that is fairly normal as the tappets pump up with oil. Are you running the correct 0W40 oil? The valve gear is a actually pretty robust with proper roller rockers, with the tappets just taking up the slack between the rocker and valve stem. They are pretty loose and rattly after the oil has drained out of them, hence the noise from cold.

 

Just me the old dude, but if it were me Id change the oil filter and see if there is a degraded o ring on the filter shaft.

You could be suffereing the oil drain down due to a bad o ring. If the torque converter drains down you rev till it fills and then you move.

Spin on oil filters have a back flow preventer that is intended to do this, and Id bet a diet coke ( coin of the realm ) that it is something like that.

In my big dodge I added (made) and accu,mulator to store oil to feed to the motor before I crank it to wet the bearings, float them.

Cheap to see, let me know back, W DY

 

Mine ticks for a few seconds, but never more than that. 0w40. At first when I heard it, I didn't like it, but after reading several threads about it, I figure it is fairly normal for this MB engine. 32K.

James

 

Thanks to all that replied to my post. My tappets noise lasts for more than a few seconds, more like 1 min. Also knocking sound. It sounds crap! Booked in at Kings Chelternam for next Monday. I'm fed up with Bristol. I will let you know what it is when I know. All the best. Paul Hindle. Portishead. Bristol. jp.hindle@ btinternet.com

 

Sorry Woody, I had to correct your post to be more accurate.

BC.

 

What was inaccurate about the reference to the oil?

 

[quote=jp.hindle@btinternet.com]When i start my crossfire from cold it knocks (tappet noise) but very loud. This lasts for approximately 1 minute. I use my car every day so it is not stood around for days. My mileage is only 12000 miles and 2 and a half years old. Some lifters have been replaced and were O.K. for 2 weeks. Has anyone else had this problem? I have 4 months warranty left. I have been told that this is normal. Some how I don't think so!!! Please can you help me and let me know. Thank You. Paul Hindle. Bristol. jp.hindle@btinternet.com Or leave a post. Cheers. [/quote] Hi all. I have had the engine checked out and I have been told that all is o.k. by Kings of cheltenham. but it is not o.k.! I have had the car from new with no problems until now. I'm now thinking of seeing a lawyer. I feel as though I am being fobbed off. Thank You for looking at this post. Paul Hindle. Bristol. J10 PWH.

 

take it to an indepenant Merc specialist for a second opinion

 

I agree. The opinion of a specialist on this particular engine has much more weight than that of a disinterested Chrysler tech that doesn't really wish to ever see these cars again.

Just my opinion, and it's worth exacly what you paid for it.

As is any opinion!

 

Based on some past experience with these things I have found that my problems were, low oil pressure, leak back of oil to the sump and contamination in the lifter or wear that required the lifters to be taken apart, cleaned, rebuilt or replaced.
Leak back occurs when the one way check valve does not seal properly, this allows the oil to flow out of the oil ways and back through the oil pump, these oil ways then have to be filled with oil to get the lifters back up to the correct height. I would think that if the check valve is stuck and does not open fully the volume pumped is diminished to a greater or lesser extent.
The longer the car is left idle I would imagine the leak back would be greater.
The older cars I saw had the check valve behind the external screw on filter, this one is close to the pump bodyI think.

 

Sorry to bring up this old thread but I wanted to thank Woody for the great info. The car has been ticking from the front of the passenger side cylinder bank at cold start up (e.g. after sitting for 9 hours). The ticking was fairly loud to begin with and would rise with revs but would quiet and go away as the engine warmed up. I should have looked into the issue awhile ago but did not. Finally searched the forum, saw Woody's posting on the O-rings and said WTF - let me try changing them. At cold start up the ticking is now much quieter and goes away after 7-10 seconds. Waldig I owe you a beer or a diet coke your choice.