1998 Chevy 1500 engine replaced

Status
Not open for further replies.
Joined
Feb 20, 2018
Messages
13
Location
Rural Virginia
I recently had the 5.0 ltr motor in my 1998 Chevy pick-up replaced. The original engine had almost 190K miles on it and I replaced it with a used motor with 83K miles on it. Mechanic replaced all the gaskets and it runs well, but the valves seem to tap a lot when I first start it up and before its warm. Any ideas on why its doing this and how to stop it?
 
Can you put on a pressure gauge? I'm wondering if it's slow to pump oil up to pressure. I presume it got an oil change when this was installed?

I forget, can valve lash on these be checked cold? I know they are hydraulic lifters, so they pump up; but I'm wondering if just pulling the covers and checking lash would be wise.
 
I'd be more worried if the valves were making noise when it's warm. It's probably been sitting for a while so give it time. I'd do a short 2000 mile oil change and then switch to a high mileage oil that readily available. Big picture - quiet and runs well when warm is good.
 
Hopefully Si permatex didn't migrate to the pickup screen.

Flat tappet cam or roller? in a truck?

Unless its a Delco or Champ non e-core filter, Ive had noise on my 4.3.

You should have an OP gauge correct? if its up to pressure quickly ( 1-2 seconds) I would check the lifter preload (incorrectly: LASH) if its a flat tappet cam. I usually preload them 1/4 turn hot. Better a bit of cold tick than a hot no seat.
 
Wow, thanks guys for all thoose quick responses, so I'll try to answer. The company in Texas I bought the motor from said it was pressure tested and is guaranteed for a year. Fresh oil was put in when it was installed, and I'm not sure about the more technical questions...I change oil on my vehicles, plugs and wires when needed, and occasionally more in depth repairs out of necessity, but I'm not a mechanic. I think I'll try the oil change with some high mileage oil.
 
It's very likely the filter. The Anti-drain-back valve is not sealing 100%. Go get a Napa Gold filter for it (w known good ADBV) and just change the filter. Top off with 1 qt 15W-40 Delo 400 and see what it does.

My bet, stone quiet when you start it up
laugh.gif
 
It is inside the oil filter. Thus, replace the oil filter. The ADBV is a check valve that keeps the oil from flowing backwards and draining out of the engine passages while the engine is stopped.
 
Thanks...I appreciate the advice...Not sure exactly what filter is on there now, but I'll get a better quality filter.
 
I'm not exactly sure if the 5.0 and the 5.7 were exactly the same those years, but I had a Vortec 350 in my 98 Yukon. It had hydraulic roller lifters. I don't ever remember them being noisy and I always used Baldwin filters on that engine. When it had a lot, like 175,000 miles or so, I replaced the timing chain and it went back to running perfectly again. I sold that truck to my brother and I think he ran it almost to 290,000 miles before selling it off.
It's been a while since I wrenched on one of those last but I think the rockers are adjustable. They were self aligning so not cross compatible with old school chevy rockers.

I would have popped the pan off any used engine and probably put a timing chain and oil pump in it before putting it in my truck, but I'm silly like that. I agree with the guys before, try a good quality filter and see if that quiets it.
 
Going to try and take care of it this weekend. I'll let everyone know how it goes and thanks again for all the advice.
 
I have a 2000 K2500 5.7L with 227k miles that has a cold-start tick which I've assumed was piston slap. It goes away after about 15sec, but I never had a clear answer on whether that was just the LS series small blocks that did that or if it also occurred with the gen1. It's a smooth-runner when warm, so I've not thought much about it. I'll check back here in the near future for an update
cool.gif

Warm Regards,
Jordan
 
I've not heard of piston slap being common on the small blocks like it is in the LS engines.

If it will help, here's the valve adjustment instructions for your truck.



Two more pics on next page...
 
Last edited:
Status
Not open for further replies.
Back
Top