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Chrysler Repair/Chrysler 300m 3.5L oil pressure spec.


QUESTION: Hello Roland,
Thank you for your quick response and reply. I am just baffled with this new problem after all the work that has been done and then some. I understand you are not a miracle worker considering the car is not in front of you and you cant hear it but I really do thank you for all your help.
If I do come across a oil pressure gauge would you know off hand what the pressure would/should read? I will keep you in the loop just in case these problems should arise with someone else.
Thank you again, Paul

ANSWER: Hi Paul,
The 3.5L oil pressure spec is: at curb idle it should be at least 5 psi (34.48 kPa) and at 3,000 rpm  in the range of 45-105 psi (300-724 kPa). But if it is below 5 at idle then don't try to measure at 3,000 rpm.
Thanks for letting me know what happens.
If you would like to go another 'rate' and 'nominate' of me that would be great.
PS: I can copy about 15 pages from the '04 manual I have on a CD and attach those to an email that I send to you directly. It sounds like you were working on the bottom of the engine so those specific pages may have something in them that would be helpful. Let me know your email address and I will copy and send those. When you tell me the address don't use the @ symbol, instead use "at", otherwise the address will be automatically erased.

---------- FOLLOW-UP ----------

QUESTION: hello Roland,
The car runs fine with no knocks (never even knocked with bad bearing when it was running) until 10-15 minutes of run time then it will ONLY knock on top when you push on the gas and gets louder over time. I put oil pressure gauge on and got 5-7 psi at idle and would go up on acceleration. It seems to be OK to me but i'm not 100%. I do not want to run for a long period of time just in case it is an oil pump issue and don't want to do damage to anything else.
Once again it only knocks after 10 minutes of warm-up and when applying gas NOT at idle and only seems to be on drivers front cylinder on top. Oil light comes on on occasion but goes away on acceleration or flickers at idle sometimes. New sending unit installed. Could it be the viscosity thinning out, a clump of crap came dislodged and plugged something up, stretched out piston rod(online suggestion), re-clogged oil filter? I don't know where else to go from here except for replacing the oil pump which is quite costly and looks to be a real project and PITA! If I do replace pump and noise continues I have just wasted alot of time and money we don't have. I am out of ideas of what could be causing this knock. I am returning to work next week after layoff and need this car up and running for the wife. The wife has been using mine for work but now with me returning to work I need mine back.

ANSWER: Hi Paul,
On the oil pressure question, see what it is when the knock begins and what is the rpm at that point, and how it compares to 45 psi. At least that should give you the answer to the question about the oil pump being the problem. Let me know what you find.
On the "knock", you said the sound is coming from the 'top' of the engine which sounds to me more like a valve lifter issue or possibly an 'interference' between a valve and a piston top.
Did the work that you have done so far involve removing the timing belt? Have you verified the timing marks when engine is at tdc of cylinder #1?  Try to verify where the cam shaft sprocket mark is for the bank of cylinders that has the knock.  If the front timing covers are all in place then you still might be able to get a good approximation of the tdc by means of a probe inserted in the spark plug socket of cyl #1 which when it reaches maximum height then loosen the bolts around the upper timing belt cover for the bank of cylinders with the knock, and try to get a view of where the cam sprocket timing mark for that bank is positioned in comparison between the two marks on the rear surface of that cover opening are grooved? It should be approximately mid-way in between those two marks.
It might be a partially plugged oil passageway that supplies a valve lifter on the affected cylinder. Did any of the work you did involve the cylinder head on the knocking side? Was there any history of sludge in the oil?
Again, if you could limp the vehicle to a machine shop slowly and have their mechanic listen to the sound that might be the best approach to pinpointing the source of the noise.
PS: If you would be so kind as to do another 'nomination' that would be terrific. You have done three so far this month, but the maximum that will still be 'counted' is five.

---------- FOLLOW-UP ----------

QUESTION: Hello Roland,
We bought the car in Nov. and water pump failed in beginning of Jan. While the front was off for water pump I did timing belt,tensioner,and pulley. The car had been running great thus far and I wouldn't hesitate to drive it anywhere.
It idle's at 750 rpm and starts knock at 1000 rpm so not much to get it knocking after warm-up. I never touched the top end. We only put 6000 miles on the car since we owned it so it is kinda aggravating that a motor can go from great to crap in an instant even with 205,000 miles on it it ran like new. I'm mystified by this new problem that was never there before and beginning to loose hope in repairing. I just cant make sense of all this. Thanks again, Paul

Hi Paul,
As I review your questions I note that you first were looking for the connecting rod cap bolt  torque specification, which suggests that you had been doing work on the 'bottom' of the engine. But I still don't know what the problem was that led to your working on the connecting rod. If the knock appeared after that work, then likely something was not done right in that work. I offered to send you pages from the '04 manual about working on that part of the engine. Let me know if you don't have those pages and I will send them by email directly to you. When you tell me your email address don't use the  @ symbol, instead use 'at', otherwise the address will be erased automatically.
Thanks for the rating of your first question today. But you didn't give a 'yes' to the question about a nomination of me to be 'volunteer of the month'. If you would do that in response to this answer I would appreciate that.

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Roland Finston


Get a 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, so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 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

Awards and Honors
"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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