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Is it normal engine noise for first 2 seconds?

3943 Views 14 Replies 6 Participants Last post by  tbplus10
well we all know that i jsut bought a suburban and am in the process of fixing it up so i can use it to tow my TT. I drove it back to Mo. for Tx. and it seems to drive fine. when i changed the oil i used mbl 1 15000 mile oil and also put the $12 Mbl 1 filter. It makes a little noise for less than 2 seconds when i start it up but than goes away. It seems to run better with the mbl 1 than when i brought it up from Tx. It just has the start up noise. is this ok. It sounds like lifter noise. but what do i know.
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did you get the anti siphoning filter, at least i belive thats what its called. it keeps oil in the filter insteed of alowing it to all drain down into the pan. giving you oil more quickly.
Anti-siphoning filter? Never heard of that type of filter.
its a filter with a check valve to keep all the oil from draining out of the filter when the engine shuts down. usually they are used on filters that are in the sideways position, horizontal.
not used in this system normally, because the filter is vertical, up and down.
just a idea, he was asking about noise at startup, the ford 300 streight 6 cyl. they are famous for rapping at start up because of this. sorry had a senior moment!
Huh, guess you learn something new every day.

That was mine, so I'm done learning today!

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I talked to a mechanic last night and he said the 454's get carbon build up around the top of the cyl walls and the pistons touching this at start up is what makes the noise. he said GM has a liquid that you put in thru the FI after the filter. he said you take off a small hose and put it in untill the engine dies than let it sit. that will make it go away. any one hear of this?
Yeah, carbon build-up has been a potential problem for years in the big-blocks. There are many factors, such as the type of carb you have (or injection system), the quality of the refined fuel, etc.

I wasn't aware of this possible solution. I'd be interested if anyone's done this.
Carbon build up. Wait til winter, it will be noisy for a few minutes. No harm done though.
You can get seafoam from your local NAPA. It will do the same thing, and costs less than having the dealer do it for you.
Ok this is wierd, you all know this is a truck i just bought. when i bought it it did not make the engine noise. I put in the new mbl1 oil and it made the noise at start up. well it stoped making the noise at start up. no more noise.
hmmm....That is strange. Maybe you had a plugged oil galley that worked itself out. I'd still keep listening for it.
Well, at least it worked itself out. Could have been any number of things. Hopefully it's gone for good.
Engine Knock

If it is a new engine and it sounds like a diesel for a bit, it is proably the piston design. GM went to skirt-less pistons with the 5.3/6.0/8.1 LT engines in 2000. After break in they get louder. When I'm in sub-zero it knocks for about 5 minutes so I just lay off the throttle until everything gets up to temperature, then it is nice & quiet. I have a 2001 K1500 with 106k - it runs fine and sounds like a can of marbles at start up.
I noticed a lot of different things happened when I swap anything we drive to Mobil 1.

Lower oil pressure after it gets warm, leaking seals that didn’t leak before, because of the uniformity of the synthetic oils molecules.

Better mileage, by a mile or so per gallon.

Noise at start up is not uncommon to.
almost all high mileage engines will suffer from knock on start-up. Build up on the lifters allows them to leak down when the engine is cold and it usually takes a few seconds to pressurize at start up. the 7.4 seems to be more suceptible to this than most engines. As stated carbon build up is a problem on GM B/B's also.
Two methods I learned to combat this problem were as mentioned Seafoam through a vacuum port into the intake manifold. And a few ounces of ATF into the oil about 500 miles before oil change.
Seafoam knocks down carbon deposits and cleans the intake runners, ATF revitalizes the lifter seals and cleans built up deposits from them.
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