I have a 1993 F350 crew-cab 5.8L with C6, 4WD SRW. This truck is retired Navy - was a plow truck on a Navy base in Rhode Island. In fact, it has a low-pressure by-pass oil filter installed by the Navy. Its been a bit neglected over the years and I put a lot of basic maintenance into it - its been a challenge but useful and fun.

I have an interesting observation about my replacement EGR valve. When I bought the truck in Feb 2014 the original vacuum lines were in pretty bad shape. Based on what I read in a forum I replaced most of the original nylon vacuum lines with 5/16 rubber vacuum lines. I started having EGR issues and decided that the rubber line dampened the vacuum signal between the EGR solenoid and the EVP sensor. I replaced this line with a hard nylon line - solved the problem. In the course of investigating the EGR problem I discovered that the original EGR valve wouldn't hold a vacuum according to specs. I replaced it with a new EGR - my troubles worsened. I began having a high EGR voltage code (334 - KOEO) and while driving would get 334, 172, 332 and 334 and no power on load. I check the EVP sensor and decided to replace it because the resistance (EVP-->Vref and EVP-->SigRtn) were out of spec while mounted on the EGR valve. I purchased a new EVP sensor. On the bench I measured 4300 ohms EVP-->Vref. When I installed onto the EGR valve now I got 2300 ohms. Turns out to seat the EVP sensor on top of the EGR valve the sensor rod on the EVP was compressed by about a quarter of an inch on the new EGR valve. I think this was the source of my 334 code. With the EGR valve closed and seated on the new EGR valve I was starting out with about half my resistance range gone. I assume since the resistance was already 60% gone while the EGR was closed my return voltage was too high. I pulled out the original EGR valve and installed the new EVP sensor on it and the sensor rod was barely compressed. I measured the height inside both EGR valves and the new valve is about a quarter of an inch shorter. As far as I can tell the new EGR valve and EVP sensor are supposed to be the proper parts for this application.

My solution for now is that I have reinstalled the original EGR valve (with slow vacuum leak) - all my codes have disappeared.

Has anyone else observed this with a newer EGR valve? or an I missing something.

Thanks very much.

Doc TeeRay

 

Welcome to FTE, please stick around. Actual technicians who diagnose & repair are few & far between & it looks like You don't fool around. Working on making an EGR function correctly is a rarity too.

I have no direct experience with your observations, but possibly someone has noticed. Was the replacement Motorcraft unit or parts store aftermarket?

Once again welcome & does the truck carry the Navy livery? (we love pics)

 

Thank you for the welcome. I have followed the forum for a while. My replacement EGR valve was aftermarket - BWD part # EGR1060P. The website I check said it was correct for the application.
Happy Thanksgiving to everyone!

 

New parts does not necessarily mean good parts. Looks like that new EGR valve is bad. There should be a small amount of preload on the EVP sensor as observed with the original valve.

 

I'm a Motorcraft "where ever available & not excessive priced" kind of guy, followed by orig parts manufacturer (like Bosch, Siemens, etc) & then BWD & store stock last. I also have no problem using JY stock stuff & stockpile it when possible for pennies on the dollar. The aftermarket has a lot of slop built in regardless of country of origin & is always a crap shoot as far as function & durability.

I suggest a Motorcraft one if available.

 

Had same problem with a New BWD EGR. Spent $168 on a New Motorcraft EGR, Zero problems with mine and that's been 2+ years.

Anything other than Motorcraft is a crap shoot!

 

I may have found a stock EGR for the truck at a JY in Rhode Island. I can't find a new Motorcraft EGR for this truck - any ideas where to look?

Thanks,

Doc TeeRay

 

Your local Ford dealer.......

My local dealer gives me a discount because I usually walk in with the part number in hand. It saves them time and I am a return customer because they are willing to work with me.

 

WWW.HORIZONPARTSGUY.COM

I get my part# here, get price + shipping & sometimes my dealer will beat it & if not I place my order.