valve tap

R

RedChuck

NAXJA Forum User
Location
Delaware
well
195000 and my first real engine problem!

it started taping there is only one tap sounds to be around cyl 3 i changed out the pushrods as thats what my boss though it was but that did not fix it. my next guess would be lifters but it sounds like it is right on top

i know this is not a 4.0 but that is the exact sound
http://www.youtube.com/watch?v=V9PQI5n3iwk
this guy says its a blow piston skirt but i have never heard that term.
 
so this would be better off in the oem tech forum. that sounds terrible. id do a compression test on all the cylinders. narrow it down. your valves sounded good. sounded like they were adjusted properly. id put money on it being in the bottom end of the engine. whats the oil look like? is there any metal flakes in it? if it were my engine, id first do a compression test, then a leak down test.
 
The 1st thing I would check would be the torque converter to flex plate bolts. Does the sound change under load?
 
yeah i found an engine in a junk yard for 750 with 50000 on it. im going to take the old one apart find the issue and rebuild it into a boosted stroker. then get a second XJ
 
Yeah, I took that video and there were 2 spun bearings at the time. My number 6 (pretty sure that's right) had spun and the sound was fairly obviously coming from the bottom of the back of the engine.
You can easily take the valve cover off and it'll run at idle without making too much of a mess, I had a valve cover I cut the top off that I used for mine just in case it was valves.
I see you want to build a boosted stroker. You'll be pleasantly surprised of just having a stroker. The Tq that it makes is amazing and I'm never really wanting for more power. I haven't really done the numbers but I think I have a fairly low compression engine and could boost if I would, but truthfully it's just not something I need, as the power is more than adequate. No external electronics needed on my build and it's still the coil rail setup with OE replacement plugs and Ford 24ld injectors.
Just my 2 cents
 
yeah i had the valve cover off but it sounded the same i was holding a long screwdriver against the head near the push rods and the sound is louder near #3 but i can't pin point if its exhust or intake so i bet your right about it being a spun bearing. maybe i should pull the oil pan before i remove the engine and see if i can just replace a bearing. i would love to just milk this engine till it pops and start on a replacement in the garage.

well i don't need any more power then stock.... but need and want have a big difference. and i know if i stroke it ill just want more later done the road. so i might as well go all out while its in the garage and apart.
:scottm:
 
You don't even really have to go all out. A low buck stroker would be good if you're geared. The low end they have is incredible. I just pulled the trigger on an all out build because I was single and had a lot of OT last fall to put to the build. Make sure you add a trans cooler when you put the bigger motor in, it cost me over 2 grand to learn that lesson.
 
i just rebuilt the 5 speed. the syncros were toast and there were some broken bits in there as well.

and thats the worst part i had it on the road for a 1.5 weeks and the engine does this.

yeah but the unexplainable joy of a turboed car makes me want that feeling in my jeep. and since all i have now is my jeep and a POS PU i want that power
 
well that's your choice. I think that the ease of the stroker build is just too good to pass up, without any FI it's just fine. Sure I'd like more power but I'm pretty happy with how it is now with gears and the motor I have
 
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