Engine/Transmission (1994 - 1998) wastegate

[Dick R]

got a couple of questions maybe someone could answer , how can you test the wastgate to find out if it is shot ? I crawled under grabbed the wastgate rod with engine off and it will move back a forth real easy , no drag or anything , ?????????? now the other question I just install a new fuel module on the tank , now when I drive the truck and shut it off remove the fuel cap I get a hissing noise like their is pressure in the tank or vacumn don't remember if it did that before don't think so , on the new module I found a plastic elbow and no place to go so I plugged it didn't want it open thinking dirt would get in the tank , maybe the darn thing is a vent ? truck isn't running right ether boast comes on way late and when it does it doesn't hit the peak it was before ? anyone .

 

[pwerwagn]

Well, if you really have a 16cm housing like your sig says, then it is not wastegated. 16's arent.



If it is a wastegated housing (12 or 14 cm), and you can move the rod easily by hand that is not right. There is quite a bit of spring pressure on that rod to keep the WG "flapper" closed until it needs to open. but, this sounds like what your problem is. It will make the turbo extremely laggy, if it ever even spools. And peak boost would be quite a bit lower too, I doubt it would ever even go to 15psi.



Cant help ya on the vent thing. I do know that my tank has suction on it when I pull the cap off though.

 

[Dick R]

does anyone know if the wastegates are spring loaded in order to keep them closed until their is enough pressure from the motor to open the wastegate ? got a power problem until the motor is turning over 2000 rpm that I never had before kind of going through a check list here but could use some advice

 

[Dick R]

I have to change things , never got around to it ,never put the 16 on yet plus other things I still have the stock turbo housing on it , all of a sudden it started acting up , checked the actuator rod it will move up & down with no load what so ever , I did put air pressure on the line to the actuator and the diaphragm is ok , is that an internal spring ? really appreciate the info .

 

[DESL PWR]

Yes the wastegate actuator is spring loaded. the diaphragm acts against spring pressure to open the gate and route a portion of your exhaust gasses directly into the downpipe. If the spring is broken you will be bypasing your turbine at low boost resulting in very laggy spoolup. Now with low/no boost coming from your turbo, the afc housing is not getting the boost it needs in order to move the afc foot out of the way of your governor arm. Hence reducing fuel flow.

 

[Dick R]

thanks for the info , believe I will tie the boost control closed until I receive the new part , as long as I watch the gauges and take it easy I shouldn't have any problems , this forum has given me great info from people that know , Dick R

 

[pwerwagn]

never put the 16 on yet plus other things I still have the stock turbo housing on it ,

Now seems like as good of time as any to do the housing swap!!! That way you dont have to order parts for the 12. Just use the 16!!

I liked the 16 way better than my 12 anyways. It drove much nicer I thought.



--Jeff

 

[Dick R]

the only thing that concerns me about the 16 is the smoke , I was considering the 14 but i'm not sure sure on how much I would benefit , my driving is regular commuting but during the summer I pull a 28 ft fifth wheel & sometime a boat behind the fifth wheel , I really don't have to much of a temp problem because I watch the gauges but it can get hot pretty fast if not careful , the other thing is the darn rusty exhaust will have to be moved back , got to think about this one .

 

[pwerwagn]

Yeah, I hear ya on the smoke. I really hate soot all over the boat, so I try to somewhat keep it down. It is harder with the 16, but not to bad. Unless you are used to pulling the trailer at like 13-1400 rpm, you will get used to it quick. On mine, it was only about 100-150 rpm difference in spool up.

I have a 14 now, but I did it with the dodgezilla. It spools great, so I would assume the 14 on a stocker would be fine. I cant notice any difference in spool between it and my 35/12. but I would venture to say it would have to be a wastegated 14. I have my 14 set to open at like 37psi shop air, and it will still hit 40-42 sometimes. I think a 14 non-wg would be enough to blow the 35 to pieces if ran hard.



As far as the exhaust, the 16 is actually shorter, so the exhaust will have to make up about an inch of room (foward, towards the radiator). On mine, there was plenty of play in the stock rubber exhaust mounts to take up the room. I just put the 16 on, and bolted up the exhaust as usual.



hope that helps,

Jeff

 

[Dick R]

Jeff , thanks for the info , I never got soot all over the camper , but when a person stops at a wayside ect & opens the camper all you smell is burnt diesel fumes , the wife doesn't go that to much , I have tried different exhaust extensions & seems the one that worked the best was a turn down , I did tie down the wastegate and drove it all I can say is that thing must have been going bad a little at a time and I never realized anything was happening , but I do have to cool it that little turbo pushes a lot of boast , it kind of surprised me , I think I will start looking for a regulated 14 & give it a try , thanks for the advice . Dick