Engine/Transmission (1998.5 - 2002) Boost gauge question....

[JMoeding]

First off, hello! I just found this site and it looks like it's full of great info.



My question: Recently my boost gauge is only showing 5psi and the truck feels a bit underpowered (or I'm just being paranoid and thinking it is). It's a mech guage and I check the tube and fittings, all look good. I also checked the intercooler couplers, all look good. What else should I check? Can I test the actual gauge somehow, it's an Autometer. Also, if I did have a boost leak, would the egts climb? Mine aren't. Also, I'm not getting any codes.



Thanks,

Jess

 

[Beast2B]

First off, Welcome to the TDR! Full of great info.

I haven't run into this trouble myself, but others have mentioned checking the mating between the air horn, heaters and intake manifold. Also, with the truck running, can you hear any whistling or hissing sounds? May need another body to rev or listen, but it may help isolate the trouble.

 

[JMoeding]

Yes, I hear whistling and hissing sounds, but I think that's just the turbo... doesn't sound abnormal. If I pressurize the system can I do it through the inlet side of the turbo or will that harm the turbo?

 

[SEmerson]

yes

get a sewer cap the same size at the turbo inlet. Tap it with a hose. Then put on a regulator. plug it into a air compresser. Works great. You must have a really bad leak.

 

[Guest]

nice leak... ... ... Definetely a boost leak

 

[Ron Bissett]

Originally posted by JMoeding

First off, hello! I just found this site and it looks like it's full of great info.



My question: Recently my boost gauge is only showing 5psi and the truck feels a bit underpowered (or I'm just being paranoid and thinking it is). It's a mech guage and I check the tube and fittings, all look good. I also checked the intercooler couplers, all look good. What else should I check? Can I test the actual gauge somehow, it's an Autometer. Also, if I did have a boost leak, would the egts climb? Mine aren't. Also, I'm not getting any codes.



Thanks,

Jess

Test. suck on line you can pull the pointer down for a test. Ron Bissett in metro Louisville Ky P. S clean the AIT. /////'

 

[JMoeding]

O. k. I still don't have this resolved and I'm getting very irritated!



I pressure tested the system to 30psi and I don't have any leaks. So I thought I may have overtightened the ferels on the boost line. So I bought new ones and replaced them, still no working boost gauge. I took out the boost gauge and I can make it move if the stick the air compressor nozzle on the back of the gauge, so the gauge works. So, then I think I it may have a hairline crack in the line. I then replaced the entire line with new ferels again. Still doens't work. It will show maybe 1psi if I really mash the pedal while driving.



I can hear the turbo spool up, but performance is less than normal... . I think. If I can hear the turbo spool does that mean that I have to be making boost?



I'm going to get a vac/boost tester and check to see if the gauge is accurate.



Any other suggestions are greatly appreciated.

 

[Jeremiah]

Originally posted by JMoeding

O. k. I still don't have this resolved and I'm getting very irritated!



I pressure tested the system to 30psi and I don't have any leaks. So I thought I may have overtightened the ferels on the boost line. So I bought new ones and replaced them, still no working boost gauge. I took out the boost gauge and I can make it move if the stick the air compressor nozzle on the back of the gauge, so the gauge works. So, then I think I it may have a hairline crack in the line. I then replaced the entire line with new ferels again. Still doens't work. It will show maybe 1psi if I really mash the pedal while driving.



I can hear the turbo spool up, but performance is less than normal... . I think. If I can hear the turbo spool does that mean that I have to be making boost?



I'm going to get a vac/boost tester and check to see if the gauge is accurate.



Any other suggestions are greatly appreciated.

Here's a suggestion: add your truck and whatever equipment you have on it to a signature line. Other owners will want to know what you're driving before they give you advice.

 

[JMoeding]

Originally posted by Jeremiah

Here's a suggestion: add your truck and whatever equipment you have on it to a signature line. Other owners will want to know what you're driving before they give you advice.

It was in my user profile, but I added it as my signature too. Thanks.

 

[Jeremiah]

Originally posted by JMoeding

It was in my user profile, but I added it as my signature too. Thanks.

Not a problem. Not all who peruse these messages take time to read profiles. I don't unless I want to know something about the person who wrote the message. OTH, I do look for drivers who have my same truck and that comes from the signature. Thanks for adding it and welcome to the TDR forum!

 

[Ron Bissett]

No boost?

Location of tap in ? best Place I found was in the air in take just as it flattens out after the hose fitting . Just remove clamp , hose end cover with cloth or paper bag tape to out side of hose ,plastic or cloth over open end of intake (to catch shavings) drill and tap for 1/8 npt or 1/4 npt ,screw adapter in attach hose your choice route to gauge remove rags paper bags ,plastic etc. replace hose and clamp test use small amount of sealer or anti-size on male thread . should find it works fine . Ron Bissett in Metro Louisville KY

 

[JMoeding]

Re: No boost?

Originally posted by Ron Bissett

Location of tap in ? best Place I found was in the air in take just as it flattens out after the hose fitting . Just remove clamp , hose end cover with cloth or paper bag tape to out side of hose ,plastic or cloth over open end of intake (to catch shavings) drill and tap for 1/8 npt or 1/4 npt ,screw adapter in attach hose your choice route to gauge remove rags paper bags ,plastic etc. replace hose and clamp test use small amount of sealer or anti-size on male thread . should find it works fine . Ron Bissett in Metro Louisville KY

I have the line tapped in at the port behind the fuel filter in the block... that's not the problem.