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Chrysler Repair/'02 300M won't idle after intake manifolds r&r


QUESTION: in Nov I took the car to a radiator mechanic, they changed the thermostat because she was not getting warm, I had to use my heated seats to stay warm and after, for about a month or so I had heat, well, the heat slowly started disappearing again, and so was antifreeze, 2 weeks ago, my boyfriend found an antifreeze leak so we changed out the intake gaskets, then the o rings because gas was spewing out of the engine while she was running, now, the car will start but dies immediately after and has to b given gas to stay running, I havent driven her since the issue started and I NEED my car, please help, it would b greatly appreciated. everyone says its a vacuum leak, the manual also says it could be the pcv valve, what can I do?

ANSWER: Hi Amanda,
Which O-rings were replaced due to gas leaking out (which parts were meshing at the O-ring and what part did you remove to replace it)? Were both the upper and lower intake manifold removed and replaced? Was everything better after the manifolds replaced, except for the gas leaking out, and then the problem with not running started right after the O-ring replacement? The point in time when the problem began is relevant to why the problem occurs as you want to re-look at your work just before it began.
I do have the manual for that engine and can copy the pages involved and send them to you by email if you didn't have them for the work that was done by your boy friend. To do that I need to know your email address, but don't use the @ symbol, instead use "at" or the address will be automatically erased from your follow-up question.
If it is a vacuum leak, one thing to try is a spray can of starter fluid which you can gingerly spray around the manifold gasket surface while cranking/giving gas to notice if any particular area on that surface cause a change in the engine idling as that would be a suspected spot for there to be a leak. But you don't want to use much of this for concern of starting a fire. I don't suspect the PCV valve unless that was removed in the repair so far.
There is a vacuum hose diagram on the underside of the hood which you can use as a reference to go over and check out all the hoses that might have been disconnected to remove the manifolds.
You might also try a fault code readout using the key: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window of the cluster to see if the mileage reading is replaced by a 4-digit number preceded by a P. Let me know what is if so. Also is this the 2.7, 3.2, or 3.5L engine you have there.

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QUESTION: I have a 3.5L v6 high output, we replaced all of the o-rings, all 12 of them, she started and died immediately after replacing both upper and lower gaskets, and the PCV valve was not removed but it is caked in oil which my boyfriend said can indicate a bad PCV valve, or an issue that may cause problems, I also have the Haynes manual for this engine and if you could tell me which pages I can read them and look at what I am doing, I am a quick learner. I didnt have any problems at all except no heat until I took it to a mechanic, I never have problems until I take them to mechanics. my email is

Hi Amanda,
Probably the best thing for me to do is to send the 7 pages from the Chrysler '04 manual, which I will do sometime tomorrow. I suspect that either one of the gaskets is not fully tightened down or that a vacuum line has not been reconnected to its original position. The PCV can be checked at least for the condition of the vacuum hose connections.
On searching for the leak, the manual instead of my suggestion of starter fluid, says to use a modest spraying of water while you have the engine running as smoothly as possible and listen for an change provoked by each squirt of water.
In you email address I assume the character before "at" is a zero, rather than a capital O. Let me know if otherwise.
Perhaps something will be on the 7 pages that differs from the Haynes manual which will solve your problem. Let me know if there are some other items you changed so I can give you the pages about those. A PCV valve is inexpensive so I would replace it.

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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.

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