97 xj 4.0 auto, 4x4 160k mi
recently when cold below ~20F, I get a loud rattle/ knocking noise from the engine compartment. either from the engine itself or possibly the front of the transmission. the first few times I try to accelerate i get the noise.
It matches engine speed, not vehicle speed, only occurs under load (will not happen revving engine in park) and goes away after the engine warms above about 120 F.
I have a few ideas, but not sure how to check/eliminate them-
do any of these seem likely?
1. flexplate loose/cracked?
2. valve starved for oil?, worn cam lobe?
3. torque converter screwed up?
4. knocking due to cold?
jeep will occasionally have trouble starting, sometimes will start, stumble and missfire for a few seconds before evening out or dying entirely.
any ideas or help appreciated.
Thanks-B
recently when cold below ~20F, I get a loud rattle/ knocking noise from the engine compartment. either from the engine itself or possibly the front of the transmission. the first few times I try to accelerate i get the noise.
It matches engine speed, not vehicle speed, only occurs under load (will not happen revving engine in park) and goes away after the engine warms above about 120 F.
I have a few ideas, but not sure how to check/eliminate them-
do any of these seem likely?
1. flexplate loose/cracked?
2. valve starved for oil?, worn cam lobe?
3. torque converter screwed up?
4. knocking due to cold?
jeep will occasionally have trouble starting, sometimes will start, stumble and missfire for a few seconds before evening out or dying entirely.
any ideas or help appreciated.
Thanks-B
