My 98 olds van has a knockin in the motor.

The fuel pump may be starting to go bad, when you get below half a tank, the pump does not submerge in fuel as much to keep it cool and it will seize up and stall the motor. You will need to replace the pump and check inside the bottom of the tank for small metal bits that almost look like shiny sand.

Please check the link https://www.youtube.com/watch?v=ccrDTK5XEQU
for Manual Valve replace. Thanks

About the only thing left is the ECM. These rarely fail, but is does happen. Any chance you can get a salvage yard spare to test with?

Hi Linda, There are a few things that could be causing a miss and stall. However one of the first things I would suggest is to look for a vacuum leak. I experienced this same situation. I found the leaking hose that led to my throttle body. Once replaced the van ran fine.

The safest way to check for a leak is purchase one of those small propane bottles used for camping along with the valve attachment to run a torch off the bottle. You will want to get about a 3 foot piece of rubber hose that would fit over the torch end snuggly. Start your vehicle and let it warm up...then open the valve on the propane bottle and take your free end of the hose and start running it around the small hoses in and around your air cleaner, throttle body etc.

Be very careful because you are going to leaning into the motor compartment. It's called a motor compartment for a reason, its for motors ..not people. (smile) So watch out for the fan that will be turning at high speed...make sure that you have nothing hanging, including hair, that can get caught up in the fan. Make sure that your skin does not come in contact with anything hot.


As you run the propane hose along the other hoses make sure that you are listening for the idle in your van to change. If you find a hose where this occurs. It will need to be replaced. Don't stop there. You don't want to go through the steps of replacing the hose only to find out the problem remains. You could have more than one hose leaking. Note each of the hoses that need to be replaced including where the hose is connected on both ends and the length of the hose. I prefer to take one end loose and cut a piece of the hose I want to replace with me to the shop to purchase a new hose. Taking photos, making notes and marking the hose with tape helps you make sure you are putting hoses back correctly.

Finally, if you choose to replace the hoses yourself, make sure that you replace the hoses one at a time so you won't get mixed up. I will usually take one end of the old hose off and place the new hose on the connection point. I then will run the new hose along the path of the old hose until I reach the second connection point and cut the new hose to the proper length. At this point I remove the old hose from the second connection point and connect the cut end of the new hose. That will complete the repair of that hose and I can move on to the next hose to repair.

I hope this helps you as I suspect that this is a vacuum leak.

My Best

Tony

Depending on what the trouble code is, the problem could be the cam instead of the sensor.

I'm showing three fan relays in the wiring diagram.
The fans are powered by two 30amp maxi fuses. The relays and fan motors are grounded thru the engine computer. The computer takes input from the coolant sensor and the ac control to decide when fans are needed. You would need to know if the computer is grounding the relays, and if not, why not. You may need a scanner to monitor computer output.

First thing I would do is check the switch for corroded contacts. You should be able to remove the switch panel with just a couple screws, it may also just pop out of the handle.

When you take the button apart and the metal contacts look good then you probably have a burnt out motor. This is very common, window motors are usually the first things to go, almost every car I've owned I've had to replace the window motors (about 10-15 years old).

The motor is fairly easy to replace, you just have to take the door panel off with a few screws and a bit of prying, then the new motor/track should bold right into place of the old one. If you need more help just reply to my solution.

blown head gasket, Is this a 3400 motor?? ok its very important to diagnos this quick. im not saying this is the problem but these motors are known for blowing the head gasket around 89,000 to 105,000 miles. What happens is anti-freeze gets into oil and if enough it breaks the camshaft in half (a lousy hollow piece of pipe with pressed on lobes) the water crystalizes the cam and it snaps causing valve damage,piston damage. Pretty much calls for a motor change as by time you put cost repairs into old motor it is a lot cheaper to do the swap. I swaped my 3400 for a 3100 and the 3100 has plenty of power and great milage. Of course though check and fill radiator and coolant reservoir till full, also need to check thermostat for proper operation.did i mention check oil level ? Is it over full? and the radiator low? I have a 98, paid 500.00 for great condition bad motor, paid 500.00 for a 3100 with 42,000 on it. after all the work " i did myself" I love this van, i"m looking to buy another one. I'd rather drive this van than my 03 yukon xl and i really like that trk also. Dont let this go on, if van is in the condition as mine (GREAT NO RUST) for a michigan vehicle, get this checked out. ITS worth the fix, Market value $3000.00 - $3500.00

Pretty straight forward depending on engine size, and whether you have distributor, or coil block. Blow out around spark plugs before removing if you have equipment. I'd seriously consider new plug wires if those are the originals, as well as distributor cap & rotor. Change one wire at a time and save yourself more trouble. Your plug gap etc should all be on hood or rad support, on the sticker. Do yourself a favor, and buy "Champion" Spark plugs as listed on sticker. I've seen too many Chrysler/Dodge products run terrible, not start, you name it, with other brand of plugs. Hardest part will be getting to them, so make sure you have extensions for your ratchet, short one, long one, universal etc, and it should make it much easier. My 3.8L has one at back of engine that is a nightmare to change. Depending on what engine, I found it easier to put vehicle on ramps & change rear ones from under the van. Any other questions or info needed, like perhaps your sticker is gone or not readable, get back to us & we'll get you that info. Good Luck, let us know how it goes.

check your throtle cables and plate in throtlebody for opening & closing properly,