Engine/Transmission (1998.5 - 2002) WHAT'S that HORRIBLE noise?

[Gary - K7GLD]

JEEZE!



Took preliminary stock fuel pressure readings on my truck - 15 psi at idle about 9 psi WOT... THEN, I installed my new Carter 4600 6-8 psi pump in a pusher configuration to assist the stock pump. Install was sort of a pain, hard to get a decent swing cutting the fuel line back close to the tank - and managed to get a diesel bath by the time I could blow air back thru the line to stop siphoning action...



BUT, got everything together - looks GREAT! Then connected the hot wire and switched on the ignition...



HOLY COW! What a racket!



The stock shock mount floats decently free, and I added rubber gromets to the frame mount - but that baby is LOUD! You could hear it clear across a good sized parking lot... Of course, main problem is the pump is up against full pressure with the engine not running - it does quiet down once the engine starts and fuel starts to flow thru the rest of the system - but I guess I'll have to seriously consider installing the additional relay the shuts down the Carter 4600 until the engine is started - plus try adding additional rubber isolation to knock remaining noise down further.



Good news is, my idle pressure is now 23 psi - seems much steadier when I hit the throttle than with just the stock LP - but won't get the whole story until I get the permanent guages in.



Where do you guys running the extra control relay off the stock pump make your electrical connection?



Nuff for now - I gotta take something to stop this ringing in my ears...

 

[Big White Beast]

Gary......

Congrats again. As I have similar readings I hope we may have helped the LP problem. I used a soild piece of rubber when I mounted mine. I doesn't seem as noisy as you describe. My truck's a rattle trap anyway because of the ladder rack and utility bed.



I made my connection as far up the wire from the LP connector that I could. Never cut the wire just stripped a little insulation and wrapped my new one around it and soldered. Thats one connection I want to make sure is solid. I then used some of the factory looking flex tubing and it looks like it was meant to be there.



Gonna get the purolator filter tommorow and plumb it in. That will put my mind at ease a little. Their web site recommends changing every 12K miles. So now it looks like 2 fuel filters to buy. Hopefully it wasn't too expensive.



Garrett

 

[Gary - K7GLD]

Garrett - I found that the filter I spec'd had REAL tight threads in/out (3/8), dunno if it was simply poorly threaded during manufacture, or some oddball metric thread...



IN any event, I used some of the purple loctite, and got it to thread in far enough to make a reliable union - no leaks, and the purple loctite is the mildest of the bunch, so shouldn't be a problem to replace. That filter is all aluminum in the housing, including the in/out threads, and has healthy wrench pads - so no problrm getting it good and tight. If I'd had a 3/8 pipe tap, I'd have just rethreaded it - otherwise it seems like a very good choice for a filter - a short 3/8 nipple allows close coupling direct to the Carter 4600, which is certainly a plus.



Thanks for info on the LP wire - I was hoping there might be an easier, more accessable spot to tap in - but before I do anything else, will see if I can get the racket down a bit - if so, might not need to do the relay bit...

 

[DEZLPWR]

Gary,

Did you use rubber isolators when you mounted the 4600 to your frame? I did, but I can still hear it doin' its thing. I actually like the nice hummin' sound that it makes. It's just hummin' with the Cummins! To each his own... .

 

[Gary - K7GLD]

Yeah, I did use additional rubber grommets at the frame mount - but not properly effective, since by the time I snugged the mounting bolts, they had pretty well compressed... I'm sure I can improve the mount for further noise reduction, but doubt it will EVER be very quiet - main problem seems to be, when the engine isn't running and fuel actually flowing, the pump is essentially totally restricted - so laboring at it's fluid stall load = maximum racket!



So, it STAYS noisy until the engine is started and fuel flow begins, then it quiets by about half - and the REST of the noise is masked by the engine noise, road noise, etc... Even tho it's not typical to have the key in the "run" position for very long without starting the engine, it DOES run long enough to frighten nearby kids and small animals...

 

[Jetson]

Yep, like a mini-chainsaw. But it won't last that long. Then it'll crapout and be quiet.

 

[Big White Beast]

Gary

I checked Napa's web site to see if they had the Purolator filter. The cross reference on that part number showed the Napa one and it was listed with Metric threads. So I'll bet that's what your's was also.



I found one at Pep Boy's. Only they had a similar one hanging there that had barbed fittings on both sides. Purolator #F33165. For the way I'm going to use it I would have had to put barbed fittings on the other one anyway. Looking down the pipe it has way less obstruction than the one with the threaded ends, pretty much a clear shot.



They also had one with one side threaded and the other barbed. I like your idea of a nipple between the pump and filter but I'll make this work.



Unfortunately no one there could give me flow rates for any of the fuel filters, altough I'm sure either of them are more than adequate.



Garrett

 

[Gary - K7GLD]

Yeah, when I was at the hardware store getting fittings for that filter, we suspected it might be metric, but they didn't have any metric 3/8 close nipples or hose barbs anyway, and I figured that with the soft aluminum threads I could get enough to make a good connection anyway - and did - but will try to get the same general size/type for a spare that DOES have the right threads - the one you mentioned with a hose barb on one end and threaded on the other would be perfect...



Got the pump mount isolated a bit better - but even when it's simply hanging out attached by nothing but the in/out lines, it's still loud - wonder if it's defective?



I got the stuff to install the relay and connect into the stock LP, but trying to make a decent connection for the added relay down near the LP is a BEAR, unless I was to remove the starter, and I'm not that dedicated! I suspect that an easier connection would be at the the main fuse/relay box in the engine compartment, if I was certain exactly WHERE to connect - there IS a relay marked "fuel system", but hesitant to dig too deep lest I smoke something I'll regret... I'll just live with the noise for a while, and see what happens - it IS quiet once the engine is running.



Tomorrow begins the A-pillar guages, and the Comp...