Jeep Strokers

To all new members and veterans, reference my build thread for background/build specs - 4.7 Build

After much time under the hood and getting everything square away, a rather odd sound has started coming from the engine, perhaps valve train, hopefully not anything more drastic.

I'm a touch over 600 miles after a proper break-in at initial start up, using Castrol Magnatec and Lucas' break in oil. Everything was fine for about 500 miles or so, but now this noise starts.

Seemingly at random while driving down the road, I'll get this super-fast tic-tic-tic-tic noise (picture the sound you made as a kid running around with your fake "mouth-machine-gun"). I let off the gas, reapply and it's gone. Further down the road it'll do it again; same procedure mentioned and it's gone again.

At idle it runs/sounds great. The stroker, coupled with a Flowmaster Super 44 and high-flo cat, sounds like a friggin V8. Normal driving - a rich, deep head-turning sound. But then this noise starts and I think the engine is gonna just shit out on me.

4.0L block (bored .60 over)
4.2L connecting rods
Bulltear forged pistons - 28cc dish - 3.935 dia
Stock head #0630
Russ' custom ground COMP Cams 68-232-4 with .435 .448 lift
New pushrods and lifters/factory rockers and springs (both in good shape)
2000 WJ Intake manifold port matched
Factory throttle body bored to 62mm (with 1" AL spacer)
Bosch Injectors (23 lb/hr) (4 hole)
Volant CAI
MSD Blaster coil
Bosch Iridium spark plugs

Other items to note:
Oil pressure is fine and climbs when driving with load
Pre/post last oil change (560 miles) [5w30 Magnatec - albeit not the correct weight and Lucas']
My roommate (XJ owner times many over the years) and another buddy, Toyota fanatic with several engine builds under his belt, and I are all scratching our heads on this.

Any ideas!?!?

exhaust header collector leaking?

CandyCaneXj wrote:exhaust header collector leaking?

Not exhaust at all. Definitely mechanical.

Evap purge solenoid?

Can you replicate it in neutral at certain rpm's? Manual or auto? Change the oil and look for sparkles.

SkylinesSuck wrote:Can you replicate it in neutral at certain rpm's? Manual or auto? Change the oil and look for sparkles.

When it happened real bad, it didn't matter if in drive, neutral or park. I shut the engine off, waited on a cigarette, fired it up and it was fine. Usually it only happens for a short period, while accelerating. One afternoon it happened as I pulled into the drive way. In park at idle it was fine. Goosed the throttle and you can hear it. After a few manual revs at the TB, it went away.

Fresh rebuilt auto trans hooked up to a 231.

Changed the oil again last night, no sparkles at all. I put in Qstate 10w40 and Lucas' (before I just had 5w30 and Lucas') Pulled the valve cover, all rockers set without wiggle.

Drove it into work this morning, no sounds at all. Tonight on the way home the sound started, I got off the gas, reapplied and it was gone. This is really odd.

I do have a thought, perhaps off course, but worth mentioning. The linkage for the t-case is not hooked up because I believe the arms are bent (can't get it aligned whatsoever). I should be getting Boostwerks linkage kit any day now. Perhaps the t-case is bumping in and out of gear???

Sounds like ae guess to me. The kind of noise you describe doesn't sound like engine to me. At least not internal engine.

Wait, you said it does this in neutral? They would preclude the transfer case then, no?

SkylinesSuck wrote:Sounds like ae guess to me. The kind of noise you describe doesn't sound like engine to me. At least not internal engine.

Wait, you said it does this in neutral? They would preclude the transfer case then, no?

Well even in neutral, internal transmission functions are still spinning, albeit not the t-case. I just got my Boostwerks t-case linkage into today, didn't have time to install it otnight; we'll see how things sound tomorrow.

Fingers crossed.

Kahlis, while your under there, pull the inspection cover off the bellhousing and check for small cracks on the flex-plate. They'll make sounds similar to valvetrain noise, or worse when they develop cracks. I had a friend sell a perfectly healthy 1/2 ton chevrolet cause he thought it had a knock. Turned out it was only the transmission flex-plate. Good luck