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View Full Version : 2.8L V6 Engine Knocking under acceleration



brianwy77
05-24-2010, 05:53 PM
I have a 1986 XJ with a 2.8L V6 it starts to knock when I acclerate. Once I get up to speed and more consistant RPM'S it seems to mellow out. Does any one have any ideal what might csuse this issue.

Thanks, Brian

4.3LXJ
05-24-2010, 09:33 PM
I had one of these. You are probably seeing signs of old age and use. I would say off hand that the rod bearings are getting worn.

default83
05-25-2010, 06:40 AM
when you say knock, do you mean a hollow knocking sound, or more of a tap?

kryptonitexj
05-25-2010, 07:05 AM
I had the exact same jeep. mine was a 1986 Laredo. I had the same issue with the Torque flight 904a 3 speed automatic. On two separate occasions it cracked the flywheel around the crank mounting bolts. Pull the inspection cover and try to move the flywheel and check for cracks. When mine cracked it sounded like a rod knock but I still had good oil pressure.