01 xj rebuild problem

[gwayms]

I had a cracked head on my inline 6. A friends shop did the work so they went ahead and rebuilt the whole motor. Took 5 weeks but thats a whole other story. Anyway i got it back today and they said there is a slight tapping noise (its a little more than slight) that will go away with a few miles on it. They put 50W oil in it, said your suppose to do that in a new/rebuilt motor. And to get the oil changed in about 100 miles with 50W again. Anyway the tapping (sounds like a lifter), Im not a mechanic but I dont think it should be making any noise. They installed new lifters.
Do this sound right to anyone?

 

[bob91yj]

No, it doesn't sound normal. The 50w could be causing a lifter not to pump up. When that engine was brand new from the factory none of that special "break in" was required, why would a rebuilt engine require it?

 

[bldeagle10]

i wouldnt say 50w either, sounds a little much, i would throw in some 10w-30 and see if that helps, if not take it back.

 

[jeepdreamer]

X3 on changing the oil...Run an off the shelf (don't need fancy or expensive here) and a really good filter. Run it gently about 100 miles then normal for another 100... change the oil. Repeat the process again but go about 500- 1000 miles. This time run a good synthetic and a top shelf filter ( like royal purple or mobile 1 oil/filter)... and drive and enjoy. Change the oil and if the noise doesn't go away within say 10 minutes (should be almost instant really), take it directly to the shop that rebuilt it. Let them diagnose it and fix it...and it will be free. Should be or that shop needs to be closed.

 

[alexfm]

here's another vote for the wrong motor oil weight. I suggest you change the weight on your next oil change to something like 10W-30. Personally, I run 5W-30 in my XJ, and it works great.

alex.

 

[DoMiNiC1]

x4... 10w-30

 

[Bodo]

50w in a new engine is an odd choice. If your rebuild included a new cam and lifters, $10 says that you wiped a cam lobe. Today's oil does not have the additives needed to protect against metal to metal contact during break-in. Many flat tappet cams have failed in our 4.0s that way

When I built my stroker, I used Joe Gibbs BR break-in oil and then high zinc Valvoline VR1 for the first couple oil changes.

 

[XJCamper]

Buddy or no buddy, Take it back to the shop and let them check it over. Or, Tell them to check it over and let them know of your concerns. If it is a lifter then they would mask the problem by adding a heavier weight oil to reduce the movement. Don't let this become your issue. You paid to have work done and should expect the work to be completed correctly.

 

[reece146]

^^^ This