Engine knock first few seconds cold 2001 XJ 4.0
12-18-2020, 02:12 PM
#1
Newbie
Thread Starter
Engine knock first few seconds cold 2001 XJ 4.0
Hello,
I have a 2001 XJ with a 4.0L engine. 103,000 miles, faithful oil changes every 5,000 miles. Out of the blue when temps got below freezing here in Detroit my engine started to knock for the first few seconds on cold start up.
I know, sounds like a rod knock? It seem lower end. Not valve train. Goes away completely after a few seconds.
oil pressure over the past year has been tracking Very low at idle hot. Around 8 to 10 PSI. Oil pressure is over 40 psi when driving. However zero knock or noise in this vehicle until now.
Advise? Recommendations? Can I pull the pan in the vehicle? Should I replace the rod bearings?
Any advice would be appreciated.
thank you,
Paul
I have a 2001 XJ with a 4.0L engine. 103,000 miles, faithful oil changes every 5,000 miles. Out of the blue when temps got below freezing here in Detroit my engine started to knock for the first few seconds on cold start up.
I know, sounds like a rod knock? It seem lower end. Not valve train. Goes away completely after a few seconds.
oil pressure over the past year has been tracking Very low at idle hot. Around 8 to 10 PSI. Oil pressure is over 40 psi when driving. However zero knock or noise in this vehicle until now.
Advise? Recommendations? Can I pull the pan in the vehicle? Should I replace the rod bearings?
Any advice would be appreciated.
thank you,
Paul
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Sirsyc0 (12-18-2020)
12-18-2020, 03:32 PM
#3
Newbie
Thread Starter
How long has yours sounded bad? Is it only cold? Mine only knocks for a few seconds. And strangely it started over night. The weather has been cold. But it started on a day where I believe it was colder than usual. Around 32 F
12-18-2020, 08:54 PM
#4
Member
Are you running 10W-30 oil? If so, you could run 5W-30 or 5w-40 to help with oil flow when it’s cold. I’ve considered running 0W-30 just for better oil circulation at startup, and with normal weight when at operating temp, but I’m not having any noise or low oil pressure at hot idle, yet....
12-24-2020, 06:17 PM
#5
CF Veteran
My guess is a lifter a little out of preload adjustment. When the temp drops is when that will pop up. Noticeable tick tick tick tick for about 5 seconds during that first fire up instant.
It could also be dirty.
It could also be dirty.
12-25-2020, 12:57 AM
#6
Junior Member
Definitely piston slap. Happens with most 4.0 engines after a while. After warm up the pistons expand and the slap goes away.
12-25-2020, 06:00 AM
#7
CF Veteran
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12-25-2020, 08:31 AM
#8
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Merry Christmas, devilled egg anyone?
12-25-2020, 01:38 PM
#9
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
What brand oil filter are you using? One that might have a sub-standard oil drainback valve?
How do you know your oil pressure gauge is accurate?
Does engine oil look like a milkshake when observed through the oil filler hole in the valve cover?
How do you know your oil pressure gauge is accurate?
Does engine oil look like a milkshake when observed through the oil filler hole in the valve cover?
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