EGR and Oil Leak

[pschrader1969]

Good Afternoon,

 

I am completely new to the comanche world. Previously owned an XJ but never had to tinker with it too much. Here's what is happening: I noticed that I had a lot of oil on the underside of 88 MJ. At first I suspected a rear main seal but as it sat in my driveway I was not noticing any oil spots on the pavement. I began to investigate further and notice a fair amount of oil on the underside of the intake manifold and a small amount of oil in the air filter. As well, when inspecting the air filter, I noticed several vacuum lines were missing or disconnected. I ordered a new front and rear vacuum harness and installed. As I was installing it, i noticed the EGR vacuum line was disconnected and where the vacuum line would connect to the EGR, a screw had been placed in the EGR to seal it. I removed the screw and connected the new vacuum line. Everything looked good so I started it up. It ran very rough (with the old harness it ran without issue). Soon it started to smoke around where the EGR connects to the manifold. I also noted oil bubbling out around the manifold and burning off. I suspect this is where the oil leak is happening and why the egr was sealed at the manifold. Two things:

 

1. Obviously I need to replace the EGR and gasket. 

2. Should there be oil where the EGR connect to the manifold?

 

Thanks in advance!

[cruiser54]

That CCV system needs to be plumbed properly.

New EGR valves are not available. Leave the vacuum blocked to it for now. 

 

Coupla things for you to look at. 

 

CRUISER'S MOSTLY RENIX TIPS

RENIX VACUUM HARNESSES

NOVEMBER 17, 2015 SALAD 29 COMMENTS EDIT

 

The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367 or is a Dorman 46003.

The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK 715-1366 or is a Dorman 46004.

The tube from the rear of the valve cover to the intake manifold is part number BK 715-1365 or Dorman 46005 and comes with the valve cover grommet.

The Throttle Body to MAP hose is no longer available. Click HERE to access a fix for that.

 

 

CRUISER'S MOSTLY RENIX TIPS

CRUISER’S VALVE COVER MOD

NOVEMBER 17, 2015 SALAD 55 COMMENTS EDIT

Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box.

A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.

Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each.

Chop 1 inch off each of them. Then, drill a half inch hole as shown in the photo. The flat side of the flute that’s closest to the edge of the valve cover. 

 

Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.

Here’s a handy video from my friend Brendan showing more detail.