Lingering questions:

Gypsy62 · **Posted:** Fri Jan 27, 2017 12:45 pm

A. This is my DIY version of the EHM; anybody see any intrinsic problems?:

B. "0073- ambient air temp sensor circuit high;"
Where is this sensor located?

C. I'm not sure which circuit to tap for the pair of stock grill-mounted mini-dome lights, now relocated to the ARB front bumper. I forget which OEM switch normally lights those mini-domes: running-light circuit? Headlights-on or hi-beam circuit?
The ARB also has a pair of switched PIAA lights; best to mate the mini-domes to their switch?

Many Thanks!

flash7210 · **Posted:** Fri Jan 27, 2017 1:06 pm

Your ccv hose looks like a EHM with a catch can. That little vent filter might allow some oil vapor to escape. If the vent filter becomes a oily mess, might be better to extend the tee'd hose down at the can and put the vent filter up high on it.
Still not quite as good as a provent connected in-line with the stock ccv hose which allows turbo inlet vacuum to pull negative pressure on the crankcase.

Not exactly sure where the ambient temp sensor is. I think its attached to one of the grill supports. Not sure how important it is but its probably not plugged in.

The factory fog lamps are switched by factory headlamp switch. Turn the headlights ON the pull the switch out to tun the fog lamps on.
They should have their own relay.
You could make your own switch and relay if you wanted.

WWDiesel · **Posted:** Fri Jan 27, 2017 1:22 pm

A. Not connected to turbo intake boot! CCV system requires vacuum from suction of turbo for correct and proper operation.
Has been discussed and explained in detail on this forum several times.
See topic:> viewtopic.php?f=5&t=80491&hilit
Best solution is to add a Provent coalescing filter and leave CCV hose connected to intake boot. The Provent filter traps and keeps the oil out of the CAC (intercooler) and allows engine to burn off the vapors!

B. On the passenger's side below the air filter box on the radiator support!

C. Not sure what you mean by "mini domes"? As to driving lights, they should be on a separate relay fused from the battery along with a cut-out switch and wired so the relay is only energized when headlights are in the HI-Beam mode of operation... See WD below:

Mountainman · **Posted:** Fri Jan 27, 2017 1:52 pm

Yeah, EHM=blown main seal. Gotta get the turbo vacuum in the loop. Main seal really sucks to change on these...

joe_ · **Posted:** Fri Jan 27, 2017 2:02 pm

Gypsy62 wrote:

B. "0073- ambient air temp sensor circuit high;"
Where is this sensor located?

This is a small black sensor attached to the grill support. I got the same code when I started mine without the sensor connected (i.e. grill support was removed), but once I reinstalled the grill support, reconnected the wiring harness, and cleared the code, it hasn't come back.

Gypsy62 · **Posted:** Fri Jan 27, 2017 2:50 pm

(Update- just read response warning of necessity of elevated vacuum to CCV. Still curious why 'antique' carb-gas setups worked okay...
Details of install below, but now I'm thinking maybe it's a better idea to replace the mini-filter with a hose back to the stock air-hose location in order to apply some vacuum, while still getting the benefit of some oil-vapor passing into catch-can instead of intake.
Update to update: However, if I apply vacuum to the top T, it will also be drawing unfiltered-air, =BAD, though the lower T vent. @$#&% !
Eureka! Relocate mini-filter to lower T's vent !
Or maybe just eliminate lower T altogether, buy a 3x 5/8's T, and apply stock-volume vacuum (=5/8") to the setup and hope that at least some of the oil-vapor finds the catch-can instead of the air-intake hose.
Yes, I have replaced many rear-main seals. No, I do not find it pleasurable.)

Thanks, Gents!

Particularly for a clearly condensed version of the mammoth EHM/provent thread. Without grasping the deep-engineering I think I still understand the basic function of a CCV:
Priority #1, vent elevated crankcase AIR pressure;
Priority #2, return OIL vapor back into crankcase.
#1 relieves stress to oil seals. Good idea.
#2 requires more toilet pape... err, I mean is to avoid dumping the accompanying oil-vapor into the environment. Good idea, too.

Incorrect?

So, reflecting back on good ole' carbureted gas motors, the CCV routed back into the top-mounted, big round, rusted-out air filter housing (waxing nostalgic: Oil Bath!). It seems like the vacuum at those beasts was minimal compared to the turbinated tap in these modern beasts. Meaning, I'm not convinced that it's critically important to replicate the elevated vacuum of the stock setup for a CCV to perform adequately; it seems more important to match the passable volume of vented air than the level of vacuum.
Towards matching the stock 5/8" vent-volume, I installed two "T"'s, one at the goofball mini-filter the other just above the "catch-can" (zipped upward), each with a 1/4" tap feeding-to-air equaling 1/2" combined venting volume (birdshot-range to the stock 5/8"). Maybe this is wrong-headed geezer-logic, but I keep thinking about a beat-up tube feeding into a beat-up tin housing sporting a faded "351 Windsor" sticker...
BTW- this was designed & developed using stuff laying around and without any assistance whatsoever from either NASA or MIT.

Thanks for "Ambient Air" info. Deploying Search & Rescue.

"DRIVING" vs "FOG" lights? The battle rages on. Meanwhile, the "mini-domes" are succumbing to laziness and getting hitched to the Hi-beam circuit feeding the PIAA-relay (easy to locate).
The PO of the donor-Gasser wisely planned that the PIAA's could only be enabled with the hi-beams switched-on.

Thanks again for taking the time.
Who knows; by the end of this surgical tunnel I may be schooled enough to knowledgeably answer a few new posts meself.

WWDiesel · **Posted:** Fri Jan 27, 2017 3:28 pm

Gypsy62 wrote:

(Update- just read response warning of necessity of elevated vacuum in CCV. Still curious why 'antique' carb-gas setups worked okay...)

If you read the entire thread on the link that I posted when answering your questions, it will explain in detail the "why's" of the vacuum being necessary in the CCV system on this particular engine...and why EHM is a bad mod!

viewtopic.php?f=5&t=80491&hilit

In short, this engine's vacuum pump exhausts into the engine's crankcase! So along with this vacuum pump exhaust and the blowby from the four pistons, there can be much more flow through the CCV puck on top of the engine versus various other engine designs including gassers all of which do not have a vacuum pump exhausting into the internals of the engine!!! Apparently the VM engineers who designed this engine wanted the extra vacuum provided by the turbo suction pulling on the CCV system?
Most diesel vacuum pumps exhaust to the atmosphere....but not this one! :wink:

Gypsy62 · **Posted:** Fri Jan 27, 2017 3:39 pm

Thanks.
Another adorable design nuance.
@#%$& !!!

Sir Sam · **Posted:** Sat Jan 28, 2017 4:58 pm

Mountainman wrote:

Yeah, EHM=blown main seal. Gotta get the turbo vacuum in the loop.

How many miles would you say with an EHM before a rear main gets blown?

papaindigo · **Posted:** Sat Jan 28, 2017 5:59 pm

Likely depends on how many miles before EHM hose gets plugged by crud or freezes up. Shouldn't overpressure rear main as long as EHM vents crankcase to atmosphere but when that stops pressure builds and something has to give.

rankom · **Posted:** Sat Jan 28, 2017 7:00 pm

i done 30.000 kms since i got MY CRD 3 years ago,,,, many upgrades ,,, yes i will get PROVENT , i have 1/2 " copper pipe with some 90 elbow so no oil in driveway or any freeze up , and that pipe was always warm to touch from hot blow by gasses , no blown seals , and i don't drive it since last winter , looks so nice in the garage ,LOL spend so much money in to so ,, yes il be spending more on lift kit summer time and oh ON PROVENT LOL

Bushman5 · **Joined:** Sat Jul 11, 2015 11:05 am **Posts:** 278

I did an insane amount of miles on my EHM........no blow seals.....but considering that a blown seal and labour up here is around $3000 , i rerouted my catch can BACK into the turbo hose ....

MM53 · **Posted:** Mon Jan 30, 2017 2:20 am

I have 80k + or - on my EHM

WWDiesel · **Posted:** Mon Jan 30, 2017 12:14 pm

But one must ask oneself, is it really worth the risks and consequences to run an EHM......I certainly think NOT!!! :2cents:

Mountainman · **Posted:** Mon Jan 30, 2017 1:35 pm

Sir Sam wrote:

Mountainman wrote:

Yeah, EHM=blown main seal. Gotta get the turbo vacuum in the loop.

How many miles would you say with an EHM before a rear main gets blown?

Mine blew in under 10k with heavy towing in warm weather, definitely not clogged. Maybe it will last forever in light conditions, but I could easily see a shop charging well over $2k to replace the seal, and then since the manual is lacking so badly, they'd probably fail to get it right. Took me two tries, and at least two other LOST members, one guy even reinstalled the transmission before he figured out it was wrong. I don't think it's worth it when stock doesn't damage anything other than stock hoses. I guess egr needs deleted also so you don't get a clogged intake.

flman · **Posted:** Mon Jan 30, 2017 2:18 pm

Sir Sam wrote:

Mountainman wrote:

Yeah, EHM=blown main seal. Gotta get the turbo vacuum in the loop.

How many miles would you say with an EHM before a rear main gets blown?

One cold day with conditions just right, vs leave the factory CCV connected and buy a (supposed rotted by oil, but never proven) intake el every couple of years and not blow seals.

There have been noobs that blew their seals reading the noob guide before they ever made a post. Hence the disclaimer.

arasb · **Posted:** Fri Feb 03, 2017 4:40 pm

Yup, just blew my main seal this morning because of a clogged EHM. Been running an EHM for years with no issues, but I decided to make the hose longer to dump the fumes behind the vehicle instead of from the side. Then... one cold day is all it took... What to do now, sell the rig or fix the main seal....

flman · **Posted:** Sat Feb 04, 2017 8:56 am

That sucks, it should really be explained the risk you take doing an EHM, rather than the unproven theory that it rots the turbo intake hose. That hose is ridged, and could crack with normal flexing, oil or not.

What led you to the decision to do the EHM?

I would have the main seal replace.

WWDiesel · **Posted:** Sat Feb 04, 2017 11:20 am

Too bad, that is very unfortunate! :shock:

Best advice, have the rear main seal replaced and install a good coalescing type filter in the CCV system like the Provent and never look back.... :wink:

Be sure and do away with the EHM mod!!!

arasb · **Posted:** Fri Feb 10, 2017 1:33 pm

Well, I might have spoken too soon. I thought I blew the main seal because I was billowing smoke out of the back. Turns out I might have caught the clogged EHM quick enough to not do any damage. The clogged EHM caused a serious amount of cylinder blow by, causing tons of smoke from the tail pipe. I immediately pulled over and cut the EHM which helped with the smoke a little. Over the next few days, the smoke started to get less and now there is no smoke but my exhaust still smells like burning oil.
There are no oil leaks under my rig, so I'm thinking that I dodged a bullet.
I originally did the EHM years back because my intake hose had deteriorated in one spot where the oil was pooling and a hole had formed.

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