my son has a 2000 ranger 4x4 with a 3.0 engine...recently swapped the engine...put a 98 model 3.0 engine...truck has been running great...last night it started blowing the rubber vacuum lines that run from the egr tube to the dpfe sensor....changed out the sensor with the one from te old engine...seems like their is way too much pressure coming from the vacuum tubes...any ideas what is causing this?

 

also it is burning up the end of the rubber line on the bigger vaccum port at the egr tube.

 

Has the CEL flashed?

My guess would be that there is some sort of blockage in the EGR tube, or possibly where the tube and EGR valve assembly connect up.

I would also check the other EGR-related hoses and make sure they aren't clogged.

 

Just took egr tube off ...its clear...changed egr valve and dpfe sensor...it still blowing off the bigger rubber hose when you rev up the engine....could this be caused by a blockage of the catalytic converter makin it build up exhaust pressure?

 

Looking at the nice pictorial Rockledge posted, is it the up & down stream hoses going to the DPFE sensor that are giving trouble???? If so, maybe suspect the orifice pictured between the two is blocked, forcing more exhaust gas to go into the DPFE sensor. That'll cook that puppy too, so it needs to be put right pronto.

 

I concur with PAWPAW. Great pick Rock....You both rock in my opinion!!! And you have helped a lot of ppl!!

 

i dont know....it is the downstream hose that keeps blowing off...i took the egr tube off and checked it...put anoher egr tube on off of the other engine...its still doing the same thing...dont think the orifice is clogged...i dont have a clue...its not throwing the CEL light either.

 

I think that's a possibility, but you indicated that the engine is running well, and usually a clogged cat will affect performance and/or throw a code.

 

Could be a restricted exhaust, if you have a vacuum gauge, hook it up & do the test for a restricted exhaust.

 

An EGR valve failed shut would probably cause similar symptoms, but again, in such case we have to assume it would be throwing a code.

Here's a few good links to review to maybe come up with more ideas:

http://www.tomco-inc.com/Tech_Tips/ttt35.pdf

http://www.tomco-inc.com/Tech_Tips/ttt36.pdf

 

I'd agree....I would at least inspect the EGR valve if not replace it. It sure sounds logical that it might be the cause of stagnant pressure and temperature buildup.

 

Put a simple pressure gauge on the line that is blowing off and see what kinda of pressure you are getting. Anything much over 1-1.5 psi at idle is to high. anything over 3 psi at 2000 rpm is to high. I saw 4.5 psi on an Expedition the other day and after we changed the cat the old one showed signs of having melted. And it wasn't running bad at idle but had a vibration and miss like condtion at speed. Even if the egr wasn't opening it shouldn't blow the hose off because the egr isn't open all the time anyway.

 

Just wanted to report that the problem is solved....the cat was stopped up...cut it off and it was clogged up...put new dual exhaust with flowmaster 44's...never knew a 3.0 could sound so mean...no more problems with it blowing the hoses off and runs 150% better..i never realized how much power loss there was..weird thing is it never ran hot or threw a CEL!! Thanks for the great info from everyone.

 

WAIT!!!! Your not finished yet!!!!

You really need to find out Why the cat melted down & clogged up!!!!

Usually it's from a messed up air/fuel ratio, so imo you need to look deeper into why the cat went belly up!!!!

Maybe consider getting a scantool that can read PID's on the computer & have a look at the short & long term fuel trim figures & maybe the PID's for the MAF & O2 sensors & maybe a fuel pressure & pressure leakdown test.

More thoughts for pondering.

 

That's a valid consideration, pawpaw. Although, kyracer6 mentioned in his OP that he just swapped in another 3.0L. So it's probable that the originating cause of the clogged cat is now on it's way to being melted down somewhere.

P.S. Good feedback kyracer6.