any mechanics I have a question
CaneyRiverDog
Member Posts: 147 ✭✭
My sister inherited a 1998 chevy 3500 with the 7.4L 454 Vortec from a family member fall of 2022. It'd been sitting for 3 plus years. BIL had done the usual stuff to get it drivable tires, new plugs, fuel filter, oil change, 3 cans of seafoam, and a new battery.
They have drove it maybe 300 miles in the last year without trouble. About 2 weeks ago they bought 2 big cans of the R134 to try and seal the ac or to find the leak to get it working. It ran fine.
Yesterday they were going to drive it to eat, they dont drive it daily, but when they started it up it had the loudest ticking noise. They sent me a video and it was clacking pretty loud in video. They had a "mechanic" friend come listen to it and he said it sounded like a lifter.
They called the local shop cause they are scared to leave the house with it and they said the 454 was notorious for sticking lifters to put a bottle of ATF fluid in it and run it down the freeway for a 100 mile trip and that would help clear the gook sticking the lifter. Then change the oil again.
I AM NOT A MECHANIC so Ive come to ask if anyone here is a mechanic with advice?
Anyone with any experience with these engines?
It's clacking so loudly my sister is afraid to drive it period ( she thinks the engine will blow)
As always I come here for the collective wisdom and thank you for any insight
Comments
I'd go with what the mechanic said. Also, check the brake calipers to see if they are sticking. I have found that vehicles that aren't driven much, the calipers are prone to stick. Personal experience on my 2002 S 10.
Its Been done for years buy many mechanics and do it your self auto parts stores have many brand name stuck lifter
Basicly do the same thing as the atf
To flush out gunk and unstick lifters run it for a while then drain it and fill up with oil
Replacing the cam lifters will not be inexpensive
And most al parts from China are junk now any way
I would at least give it a try or pick up if the over the counter bran's and give it a try few dolarsvs hundreds in Replacing
Sounds like a lifter isn't good enough. Find a mechanic they trust.
To much 134a in the aircon
my SIL's husband
tried to Fix the AC in her SUV at least he tried
They Never ask for me to help or any questions not that I am a expert but I have done my share of AC Repairs and charging
But He overcharged it destroyed the system (vompresor ) and 1 k later a local shop relaced and repaired it she was not a happy camper
I did not hear about it till ot was all done
I would check for a broken rocker arm too.
If it was running fine prior to the AC refill, I'd look at the AC compressor rather than stuck lifter.
IMHO 'stuck lifters' are immediate upon initial start up.
This. Overcharging the system can lead to the compressor being severely damaged.
Can they get a read on where the noise is coming from? One of these is pretty handy for localizing noises and is only $7.99 at Harbor Freight.
Yep, add that to the fact that with today's oils, sludge/stuck lifters are a rarity.
He said he only put one full can and maybe a half to two thirds of the second can in. The compressor started to engage and disengaged after a little from the second can. He said he put a little in at a time out of the second can till the compressor kicked on and kept running and the air started blowing cold per the Orielly's employeee where he bought it.
https://www.oreillyauto.com/detail/c/a-c-pro/oil--chemicals---fluids/air-conditioning---refrigerants/a-c-leak-detectors---sealers/7ab1c1071a55/a-c-pro-a-c-stop-leak/int0/acp108?pos=10
The air isnt blowing cold now and the compressor isnt engaging to run anymore. They havent looked for leaks with the uv light or messed with AC since this problem seems more important.
Hard to say without hearing and seeing it first hand. I HIGHLY doubt it has anything to do with the AC, since the mechanic said lifter. Those 2 sounds are completely different and come from diff areas.
IF it is the lifter, then I have had good luck with seafoam. Just pour a can into the oil. Drive 50 to 100 miles, then change the oil.
There is a CHANCE the seafoam will break loose old sludge inside the engine and cause clogs somewhere, just FYI.
Could be a timing chain/belt issue, hard to know without getting hands on it.
PS, no experience with that exact engine.
Tell them to run a diagnostic test on it, simple and cheap to do, some are even free. I personally don't like electronics on vehicles but admit in many cases it will correctly show exactly where the problem is when people are stumped as to the problem.
"Never do wrong to make a friend----or to keep one".....Robert E. Lee
ALSO, check the oil level and oil pressure! If either of those are low, it will cause excessive lifter ticking!
One of my buddies bought an old Pontiac with very low mileage from sitting more than being driven.It had a loud engine knock and he bought it dirt cheap.He ask my opinion on the knock and I told him I suspected a stuck lifter.We changed the oil and put in a bottle of Marvel Mystery Oil.After the engine warmed up he revved it a couple of times and the knock went away.I think he drove that old less than a hundred dollar Pontiac for several years.
Yep, Marvel Mystery Oil is some good stuff.