Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Ram Truck Chat

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 06-19-2014, 03:22 PM
moparman67_69 moparman67_69 is offline
Inactive User
 
Join Date: Mar 2007
Location: Hopkins, mich
Posts: 63
Default 95 Ram 1500 5.2 vacuum

I am finding no vacuum leaks & truck idles real smooth carring 19 inches of vacuum. Slowly increase throttle and vacuum slowly drops off. Wide open throttle and vacuum drops off to nothing and does not come back up until you let off the throttle then again it comes back up very slowly. It was suggested maybe the catalytic converter is plugged, but do not know how to check it short of taking it off and see how it runs. Any other ideas ?
Reply With Quote
  #2  
Old 06-19-2014, 07:46 PM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Biggrin

Plenum gasket.
Reply With Quote
  #3  
Old 06-19-2014, 09:57 PM
JVMopar's Avatar
JVMopar JVMopar is offline
Senior Member
 
Join Date: Feb 2000
Location: Mellen, WI
Age: 42
Posts: 2,524
Default

What other driveability problems do you have?

Is the truck low on power during WOT operation?

But from what your describing, vacuum slowly dropping during steady part throttle operation is a sign of plugged exhaust.

There is a simple way to test your plenum gasket. If you remove the breather and PCV valve from the valve covers. Plug the PCV hole. Start the truck and hold your hand over breather hole. If it pulls a steady vacuum on your hand then the plenum gasket is leaking. Normally there is pressure in the crankcase so it won't pull a vacuum.
Reply With Quote
  #4  
Old 06-19-2014, 10:32 PM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Biggrin

A bad plenum gasket can cause oil to be ingested, burned and sent out the exhaust where it will plug the converter.

I had a 1997 Ram 2500 that used a quart of oil every 800-1000 miles since brand new.

I drove it 230,000 miles and went through 4 cats due to plugging. The dealer did the plenum gasket twice and I did the third one, installing a Hughes Engine Plenum Kit that stopped the leakage for good. Still, 800-1000 on a quart probably due to rings/valve seals. When the plenum gasket would really let go, the engine used a quart of oil every tank of gas.
Reply With Quote
  #5  
Old 06-20-2014, 10:09 AM
moparman67_69 moparman67_69 is offline
Inactive User
 
Join Date: Mar 2007
Location: Hopkins, mich
Posts: 63
Default

To JVMopar: other driving problems are a slight stumble during an easy take off, and low to no power under WOT. Also have replaced the EGR transducer 3 times due to the casing melting and causing a vacuum leak. Also changed EGR valve and most vacuum lines.
Reply With Quote
  #6  
Old 06-20-2014, 10:12 AM
moparman67_69 moparman67_69 is offline
Inactive User
 
Join Date: Mar 2007
Location: Hopkins, mich
Posts: 63
Default

To Dick: With what you are saying I could potentially be looking at both the Plenum gasket & plugged cat ?
Reply With Quote
  #7  
Old 06-20-2014, 02:02 PM
Dick's Avatar
Dick Dick is offline
Registered User
 
Join Date: Oct 2001
Location: Western NH
Age: 80
Posts: 8,880
Biggrin

The leaking plenum gasket allows oil to be sucked into the intake and burned in the cylinders. You won't see blue smoke out the tailpipe because the cat is blocking those emissions. Eventually, the cat is plugged.

An example, my Ram went 230,000 miles using a quart of oil every 800 to 1,000 miles. The cat(s) absorbed 230 to 287 quarts of burned oil emissions during their lifetime.

You can check for a plugged cat by rapping the side of it with a rubber mallet. If you hear stuff rattling around, it is plugged. I had one plugged so badly that the truck slowed down and stopped dead, choking on its own exhaust.
Reply With Quote
  #8  
Old 06-20-2014, 09:27 PM
JVMopar's Avatar
JVMopar JVMopar is offline
Senior Member
 
Join Date: Feb 2000
Location: Mellen, WI
Age: 42
Posts: 2,524
Default

Sounds like the converter is plugged.

At work I simply unbolt the y-pipe and go for a short test drive. If runs better then you know they are plugged.

Converters plug for lots of reasons. I wouldn't condemn the plenum gaskets without having the other driveability problems and oil consumption.

Simply check the gasket. It really doesn't take very long to hook a vacuum gauge up and pinch off a few hoses. In fact there is a TSB 09-05-00. Tell you exactly how to check it and even has pictures.

Here is a link to the TSB http://dodgeram.info/tsb/2000/09-05-00.htm
Reply With Quote
  #9  
Old 07-22-2014, 07:24 PM
moparman67_69 moparman67_69 is offline
Inactive User
 
Join Date: Mar 2007
Location: Hopkins, mich
Posts: 63
Default

As it turned out the converter was plugged. I removed it and it runs like a champ.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
HELP 4x4 vacuum fun kudah440 Ram Truck Chat 2 05-06-2003 10:34 PM
Anyone use manifold vacuum for their distributor's vacuum advance? 440cj Performance Talk 30 12-28-2002 05:22 PM
Transmission difference between 01 1500 5.9L vs. 03 1500 5.7L? Blue02Ram Ram Truck Chat 11 12-28-2002 05:07 PM
Anyone use manifold vacuum for their distributor's vacuum advance? 440cj Engines 29 12-28-2002 12:26 AM




All times are GMT -4. The time now is 11:03 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .