Help!! Ihave a 2003 1500 ram van with the 5.2 magnum. Bought used with24k on the odometer. Right from the start I've been plagued by a high pitch whistle that only occurs in the cold weather. Whistle is intermittent and can occur at any speed, and doesn't matter if engine is up to temp or not. Give it a little more or less throttle and the noise goes away. ( will fade in or out like an air whistle being throttled by a 1/4 turn ball valve) Whistle almost always appears while maintaining a steady speed. Tried disconnecting all the vac lines and plugging them at the manifold - still whistles.( even tried it with brake booster disconnected and capped - scary! ) Changed throttle body and gasket, tried driving with air cleaner assembly off, checked for restricted exhaust, cleaned IAC, tried unlit propane torch trick around manifold, T.B.,& vac lines. Checked intake manifold for oil on the plate- it was pretty clean, not surprised as I wasn't using any oil.Took the van to my local garage, they did a "smoke test" and found no vac leaks, did a test drive with the scanner hooked up and everything checked out normal. Convinced it was a vac leak , I installed a vac gauge- @100 KMH it only runs about 10" Take it out of O.D. and the vac runs 18" to 20" and I'm getting about 18MPG. With the O.D. on with the lower vac reading I get 12 to 14 MPG. Out of desperation I took it to the dealership (now at 58K). After checking it out, they told me the whistle was the PCV valve and hose, but the engine had so much blow-by, they were going to change the motor under warranty. ( excess blow-by without oil consumption?) Was told no motors were available in the system,I'd have to wait awhile. While I waited (about a month) I tried driving the van with the PCV valve removed and the line capped- made no difference-still whistled. When I got the call the motor was in, I was told it was a 2 day job ( sounded about right) 1 month later I got my van back just as the weather was warming up so it didn't whistle at this time. This is after they installed a re-man factory short block, new water pump, serpentine belt and clutch fan. Now it's cold again and the whistle is driving me nuts, and I don't always remember to disengage the O.D. so the mileage really sucks. ( I was told by the dealership the overdrive can't be defeated without opening up the tranny and then I'd have to ignore the check engine light) On a side note, when in overdrive and maintaining a constant speed ( by foot or cruise) the heater controls will only switch modes once or twice , then won't work until you back off on the throttle to bring the vac up again ( the vac reservoir must be not leaking) If the van is driven out of O.D., the heater controls all work properly. I'm all out of ideas and really flustered.I've talked to anyone who'll listen , both backyard and proffesional mechanics who are all stumped-nobody seems to have an answer for me. Anybody out there with an answer ?
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My dads 5.p would whistle but only at certain speeds or engine load. It was the air intake or where/how it mounted to the throttle body. Have you taken yours off and driven without it a short distance to see if thats where yours is coming from?
Thanks for responding- tried driving with air cleaner assembly off- still whistled. About the only thing I havn't tried is driving with the engine cover/hump removed , too much noise and cold to be much help pinpointing the source. It's -18 C here this morning.
The whistle is intermittent- may not whistle at all on a 50 mile trip, next time it might whistle thru a 20 mile stretch. The breather on the valve cover was cleaned before I tried driving with the air cleaner off. When I changed the throttle body, it came off of a 5.2 that didn't whistle and it was swapped in as an assembly with the IAC, TPS, and MAP (yes, I used a new gasket). If the original MAP was leaking, wouldn't it have shown up with the propane test?
I had a good vacuum leak I could hear, and see the crack, but when I dowsed it with propane, it did not change the engine note enough for it to be a valid method for finding the leak. Perhaps with older carb's engines it works better than one with multiple sensors helping to control the A/F ratio.
Try the 3 foot length of garden hose to your ear, the other end around different parts of the engine to find the source of the whistle.
I know my first post is a long one, but I wanted to be as detailed as possible in what had been checked and could be eliminated. Whistle only occurs when driving in cold weather.Vac at idle @22". Whistle still ocurred with ALL vac lines disconnected and the manifold vac ports plugged. When the dealership installed the short block, all new gaskets were used- problem persists
Whistle only occurs when driving in cold weather.Vac at idle @22". Whistle still ocurred with ALL vac lines disconnected and the manifold vac ports plugged.
Mine has a slight whistle sound as well BUT only on cold mornings where the ambient temperature is around or below 35 degrees AND engine is at same temperature. I believe both our vans are getting the whistling sound from the IAC motor as the air goes past it and its port. When the air is that cold the PCM will give the injectors a little more fuel and close down the IAC more than on warmer days or with a warmed up engine.
On your HVAC system check/replace the one way check valve on the right side of the intake manifold and the line going to the vacuum bulb behind the passenger headlamp.
The whistle I'm talking about is LOUD- pedestrians stop and look around and animals run for cover. You didn't mention if your whistle goes away when your engine gets up to operating temp, mine doesn't. I'm assuming the check valve to the vac reservoir is okay since the hvac controls will operate air damper once or twice for quite some time after shutting down the engine. The IAC on my original T.B. was cleaned , and it whistled with the second T.B. assembly I tried . I also tried disconnecting the vac line for the HVAC and plugging the manifold port- still whistled . Any other ideas?
The fan clutch was replaced (annoying roaring noise), the tensioner pulley was changedas well- havn't touched the idler pulley yet, but this whistle doesn't sound like a bearing noise. The slightest change of throttle will make it fade in or out while trying to maintain a constant speed. The exhaust system was checked for restriction by removing the forward O2 sensor at the cat and installing a gauge-can't remember exactly what the rading was, but it was within spec. Thanks for you input. What the heck am I missing ?
My 2001 B2500 is whistling too. It's from the serpentine belt when the temps get really cold out. The colder the more it whistles. I've added belt spray to no avail. So, when I get so money, the belt will be replaced.
The belt has been replaced already (2 belts before 60K ?)
It's damn cold here this morning- almost -30. Whistling like a banshee. I'm going to enlist my son's help to try and post a video/sound clip. Can't believe it's this hard to nail down the problem.
So far, no one has commented on the vac gauge readings or the fact that I get allmost 4 MPG better with the overdrive off. The build sheet states axle ratio 3.55 the gears are stock as far as I know and I'm running the stock P245/75 R16 tires. I havn't gotten around to installing a temporary tach yet, but when the road test was done with the scanner hooked up, I was told " everything checks out normal"
My best chance at resolving this issue is to hear from someone who has gone through the same thing and hopefully found a fix.
We use to own a 4-cly 1992 Plymouth Acclaim, bought new. After four years, it started to belt whine a great deal. The problem was the alternator pulley became miss aligned. That's the only problem I ever had with that car.
It's damn cold here this morning- almost -30. Whistling like a banshee.
I don't mean to but I truly think you're having an issue with one of the pulleys. Just last month there was a loud whistling sound coming from under the hood of my Expedition. You would've sworn up and down that it was a vacuum leak but it wasn't. It turned out to be one of the idler pulleys wasn't turning. That's right, frozen solid, but only when cold.
The belt was fine and was sliding over it, smooth as silk. As soon as the engine warmed up and got some heat into the pulley's bearing, it would start turning and the noise would go away.
I just finished checking idler and tensioner pulleys- both hot and cold. Both bearings appear to be O.K. I ruled out the A/C clutch bearing as the noise occurs with or without using the defroster ( compressor cycles on defrost). Rule out the water pump bearing (new pump). Hot or cold, the alternator and power steering pump feel O.K.
I've driven this van with this noise for 48,000 KM. If a bearing was making the noise, don't you think it would have completely packed it in by now ?