Hello all.

First post. My name is Mike, and I am trying to help a very good friend of mine with some problems on his recently acquired 2000 Oldsmobile Silhouette mini-van. it has the 3400 v6.

He has been having a problem with it randomly shutting off, it usually re-starts and will run fine until it randomly shuts off again...

Then it started running hot, so he has just (today) replaced the water pump and the thermostat, both of which were apparently bad because that fixed the running hot and no heat problem. (he had no coolant circulation, new pump solved that. he also boiled some water and put the old thermostat in it and it never opened, so he replaced it. now all is well with that aspect of it.)

Still is shutting off randomly.

Also when he started the job of replacing the thermostat he noticed a plastic tube laying loose in the engine bay. One end of said tube connects to the air intake duct after the mass air flow sensor, right next to what I believe is the intake air temperature sensor. The other end of the tube looks as though it should go to the rear of the engine somewhere but we don't know where, and can't find anything about that tube in the haynes manual. We're kinda stumped.

What ever that tube is it'* causing a service engine soon light, but he could not tell me the code. :( Guy at advance auto parts said the code for the SES light had something to do with vaccum and fuel vapor from the engine????

Friend is in Florida, I am in SC trying to help as much as I can, but I'm at a total loss not being able to be there and see it in person. Does anybody happen to know where that tube is supposed to attach?

Thanks

Well im drawing a blank on that engine but we may be able to find a vaccum diagram..Actually some vehicles have one under the hood somewheres

Ah, indeed there is a vaccum diagram on a sticker under his hood, unfortunately it doesn't show that one.

I'll get him to look in the manual later and see if he can find anything. I don't think we looked there for a vaccum line routing diagram...

They just have to make these newer vehicles so complicated...

I'll also ask if he'll go back to the parts store and have the codes pulled again, and this time get the print out from the guy so we'll know what the code is, I'm sure that would help.

tube is for pcv. one end goes into elbow i think the other went into the valve cover or something under the coils. tube is hard plastic if you put it that way you should get a good idea just because its not going to bend to anywhere else besides where it needs to be.

Should be the PCV vent tube, connects at the back of the valve cover, opposite side of the PCV I believe. Since it'* a vent, it shouldn't cause any codes.

Need the code. Does it start right back up, has to sit, stalls just at idle, foot on/off the throttle, engine hot/cold? Again, need the code.

Possibly a crank shaft position sensor, which will not show up as a DTC (diagnostic trouble code). Good to get the DTC'* pulled though in case it is something else.

Heres the pcv valve and tube routing.

Hey guys,

sorry I disappeared, being a middle man in the conversation complicates it a bit.

Thank you for all of the replies. My buddy did find where the tube went and was able to reconnect it, it does go to the rear valve cover, and is hidden from view, had to feel for it. He was able to reset the SES light and it has stayed off. He never did tell me what the code was.

He also fixed the random shut off problem, that was due to a faulty ignition module. A heat sensitive part that is mounted in a high heat environment.

So for now I think he'* good to go. He did mention something about the security light being on and the Airbag light is on. But the van is up and running and he hasn't had any further problems so far.

thanks for updating