Engine/Transmission (1994 - 1998) An unusual symptom - what's up with that?

[WBusa]

I garaged the Ram last night... that's unusual all by itself... and in the morning (at 45* in the garage) when I clicked the key to the first position, the "Wait To Start" light was accompanied by a soft, high squeal from up high under the hood... a lot like the sound a half-full screw-cap soda bottle will make when its left in the sun, builds up pressure, and starts leaking pressure past the cap. The sound stopped at exactly the same instant the WTS light went out. Other than that everything's running great, started up fine, no problems... but a new noise always bears looking into, right?



My first thought was a tiny leak in the intake manifold gasket... either the one above or below the intake heater. I figgered the intake heater was heating the air in the manifold, thus raising its pressure, and that pressure was bleeding past a leaky gasket, thus making noise. But the more I think about it, that can't be right... the intake is completely open to the atmosphere via the intercooler, turbo, and filter, so it can't possibly build up any pressure (my filter is clean and new). My second guess was that the noise was coming from the solenoid that (I'm guessing here) must control the intake heater... but in my experience a bad solenoid buzzes, it doesn't squeal.



OK, Dodge Detectives... anybody care to make a guess? A short-dog of Stanadyne to whoever comes up with the right answer!

 

[ctd8999]

Busa, That noise was comming from your grid heater, no problem. Thanks Steve B.

 

[B.G. Smith]

You might hava a battery with a weak cell, when the load of the grid heater is applied, that cell produces a lot of gas and you are hearing the gas escape through the vent in the battery cap. Could also be as you suggest, one of the solenoids that operate the heater. bg

 

[mechanic]

I agree with Smith. I think what you heard was one of the batteries. This is a serious problem because that gas that the battery makes is a mix of hydrogen and oxygen, add spark or heat and... any question? I have seen several batteries blow-up when an internal cell connector opened or produced an arc and ignited the gas in the battery. Makes a magnificant mess of everything under the hood and if it is open at the time, of everything and everyone in the area.

 

[tp0d]

A third on the batteries. Mine did that (particularly the drivers) for quite a while before I replaced them due to dying when cold. When I put a small 3 amp charger on them, they would sizzle like bacon, and eventually push water out. Damn cheap batteries. . owell. . Got a new set of TurboStarts from my local parts guy for 56 each, 625 cca, original size replacement (old ones were smaller, but taller)



-j

 

[WBusa]

Well, okay, clearly a lot of smart people are thinking its the batteries, so I'd be a fool to ignore that. I'll admit I'm a little skeptical, however... we're talkin' a matched pair of Optima red tops here, not more than 4 months old, holding a full charge just fine.



Not sure exactly how to check this out. I guess I'll pop the hood before I next turn the key, and try to get my ear up to the battery. Problem is, it seems to be very intermittant... I've heard the noise only that one time... .



Thanks, guys.

 

[Jschafer]

I have heard this once before on my truck and I was sure it was the grid heater selenoid I thought it maybe was due to the heavy moisture in the air that day, just a thought

 

[KPerson]

Mine does this every time I start the truck. Up here in Canada it's well below freezing right now and when I turn the key they wait to start light comes on and I get that high pitched noise until the light goes out. It's hardly noticable but it's there.



It's done that since day one.

 

[tp0d]

I guess its possible you could have a solenoid with arc burn on it, and its whining when activated. Any moisture on the grids themselves could also make a noise as they burn off to steam. . hmm. . my lead acid's definetly made that noise tho, the replacements are nice n quiet. .



-j

 

[Timinator]

Mine has done that for years. It's most noticable when you're in a very quiet place, such as a garage. My guess is that it's been making the noise for a while, but the garage was quiet enough to let you hear it.