Rattle noise

MAXP

MEMBER
2005 DODGE DAKOTA
4.7L
V8
4WD
AUTOMATIC
117,000 MILES

I had a mechanic replace both cylinder heads at 106,000 miles due to cracked heads as it was losing coolant out the exhaust. They had the truck for two months due the issues which they eventually resolved. Well the very next day on a cold start up I noticed a rattling noise that lasted a few seconds. Not a ticking noise. As if it was a timing chain dragging is the best I can describe it. I gave the truck back to them two to three more times which they had for extended periods trying to resolve the issue. It got to the point where I just gave up with them. Truck is now just shy of 117,000 and still has this issue. First cold start of the day it will do it and then usually fine rest of day. There can be a period of a day or weeks where it will not do it at all. Really lost with this. Not sure if this is something they did wrong or? Just looking for some direction. Thank you.

Saturday, February 25th, 2017 AT 6:14 PM

1 Reply

STEVE W.

MECHANIC
14,865 POSTS

The 4.7 is well known as a noisemaker. Common reasons for cold start noise are the timing chain slack adjusters, the timing chain sliders, lash adjusters that bleed down overnight and piston slap. Sometimes it lasts a few seconds or up to a minute.
The only real way to hunt it down is to attach something like a chassis ear to the various areas and cycle through the sensors as it is making the noise. Even then it can be real difficult.
Then start hunting with a single point mechanics stethoscope. If it is the lash adjusters in the heads you can usually narrow it down because they will be a bit noisier even when you do not hear the noise you hear now.

My wife drives a Liberty with the baby brother 3.7 in it. It has had a slight rattle at cold start since around the 80,000 mark. It has got 235,657 on it at the moment, still has the same rattle.

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Sunday, February 26th, 2017 AT 7:43 AM