Is This Normal?

[Parentnoia]

Let's start a thread where we ask simply questions about what some of us perceive as abnormal or irregular. Nothing major or unrepeatable. Things that our vehicles do everyday that dont necessarily make driving difficult or anything. Just their quirks. I'll start.

'99 GMC SUBURBAN 5.7l Vortec

1. Is it normal for the RPMs to surge momentarily (by about 500 RPMs) when shifting into Park? In OD, it idles at around 500 RPMs (give or take a sliver on the Tach) and when I shift to Park, it surges to around 1000 RPM before idling just above 500 RPM (in park). Idle drops into its normal range anytime I take it out of park (reverse, neutral, etc.) It's just Park that surges the RPMs.
   
   
2. Is it normal to be able to hear a distinct whining from towards the rear when the key is turned to ON (but not started) for a moment and then continuously while running. I've been told it sounds like it's the fuel pump wanting to go out.

Let's hope this works out. I didnt put it into a specific subforum simply because engines of all types may benefit from some of the answers or questions.

 

[kamokevin]

Let's start a thread where we ask simply questions about what some of us perceive as abnormal or irregular. Nothing major or unrepeatable. Things that our vehicles do everyday that dont necessarily make driving difficult or anything. Just their quirks. I'll start.

'99 GMC SUBURBAN 5.7l Vortec

1. Is it normal for the RPMs to surge momentarily (by about 500 RPMs) when shifting into Park? In OD, it idles at around 500 RPMs (give or take a sliver on the Tach) and when I shift to Park, it surges to around 1000 RPM before idling just above 500 RPM (in park). Idle drops into its normal range anytime I take it out of park (reverse, neutral, etc.) It's just Park that surges the RPMs.
   
   
2. Is it normal to be able to hear a distinct whining from towards the rear when the key is turned to ON (but not started) for a moment and then continuously while running. I've been told it sounds like it's the fuel pump wanting to go out.

Let's hope this works out. I didnt put it into a specific subforum simply because engines of all types may benefit from some of the answers or questions.

1. RPMs rising when shifting into park is normal, but mine only increases a couple hundred rather than 500.

2. This is most likely your fuel pump, mine is also noisy. I've heard when they get to be that loud they are about to die, but mine has been that loud for years

 

[dlytle]

Is it normal for my oil pressure gauge to jump around? 91 k1500 w/ 350. At ideal it is really low then i push on the gas and it jumps up to around 3/4 of the gauge then right back down. There is plenty of oil in her.

 

[BlK89EXLB]

Parentnoia--- #1 a surge is normal, that's a little higher than I've seen on a 350, but it's been awhile since I drove a stock Vortec 5.7
The engine is under a slight load and releasing into park releases that. like pulling on something and the strap comes loose, you'll surge ahead.

#2 - Yeap, it's a fuel pump. it'll stay noisy for 30 years or fry in 2 days. no telling, but once the sound is there, the clock's ticking. POR-15 your tank if you pull it to replace.. nevermind your in Texas, damn thing probably still has stickers on it.

dlytle-- - could be a few reasons for that. anything from a failing oil pressure sensor, faulty gauge to bad piston rings, cam bearings, a weak oil pump.
Oil pressure will jump a little from idle to load, and from cold to hot. but shouldn't be more than a 5-10PSI change for a good tight motor...

if the oil and filter are fresh, pull spark plugs, check for heavy fouling and do a compression test or take it to someone who can, if that and the gauges and sensor check out normal, it could potentially be cam bearings or an oil pump. either of which require allot of work. and it's a tough call to even put that kind of work in a tired TBI 350, when at the pull yards here you can choose from 100 TBI 350s for $300-400. or with no machining, rebuild yours for $1000, $1800 if you over bore, deck and blueprint it.

 

[TerryD]

Is it normal for the RPMs to surge momentarily (by about 500 RPMs) when shifting into Park? In OD, it idles at around 500 RPMs (give or take a sliver on the Tach) and when I shift to Park, it surges to around 1000 RPM before idling just above 500 RPM (in park). Idle drops into its normal range anytime I take it out of park (reverse, neutral, etc.) It's just Park that surges the RPM.

Kinda sounds like your idle air motor (aka: IAC or IAV) is developing a bad spot and jumping when the load is released. They are cheap and easy to replace. Shouldn't take but a couple minutes to put it in.

 

[SilveradoGuy85]

2. It's the fuel pump, but mine has been whining ever since it was brand new and has been working just fine. I don't like it, but it doesn't bother me anymore. I also don't hear it unless I just turn the key to the "on" position, if the engine is running the exhaust (true dual Flowmasters with X pipe) drowns it out lol.

 

[thz71]

in simple terms yes both normal haha

 

[copernicusd]

mine seems to get water on the dipstick, maybe I have a leaking gasket, but oil isn't white when I drain it, just black
i'm convinced that the dipstick just gets moisture in it, and I never drive it long enough to burn it off
last engine did it for 6 months or so, til I decided to do head gasket in febuaury, something must have went wrong, didn't prime engine maybe, and engine made horrible noises afterewards, so I quite driving, feel like if I never messed with it it would still be going
and the mystery leak on passenger side, I think it only happens when it rains, but haven't figured out if its the door, or under the hood

 

[Parentnoia]

Well, now the truck has started backfiring when coasting to a stop, but not when braking.