Re: Mystery oil pressure problem

From: Darrell Ramsell (daram@comcast.net)
Date: Tue Oct 18 2005 - 00:23:51 PDT


Once again Glenn I feel you hit the nail right on the head. Everything you
mentioned explains all the symptoms that I had. I also appreciate the
lengthily and well written explanations too.

Some other friends of mine who own military vehicle have told me that when
I'm bellowing black smoke I'm usually pushing the engine too hard. So when
ever I'm driving I always take a peek at my exhaust, especially when
climbing hill. If I see black smoke I let off on the gas. At night though,
it's almost impossible to see.

I admit last Friday that I was pushing the vehicle a little harder than
usual because I was way behind schedule and I was trying to make up some
time. Now I understand the limitations of my vehicle that much more.

I'd like to thank you again for your help. In fact I would like to thank
many of you on this list. I've owned a military vehicle for only one year
and on top of that it's my first diesel engine too. If it weren't for many
of you good people on this list I probably would have pulled my hair out a
long time ago. But with your help and a few others not on this list, I've
manage to get my HMMWV looking and running better than when I first got it.
Still needs some work which I know will probably never end but the major
stuff is done. If any of you would like to see a picture of it I'll be glad
to send it to you.

Thanks again

Darrell

----- Original Message -----
From: "G Shaw" <K9ESU@aim.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Monday, October 17, 2005 7:19 PM
Subject: Re: [MV] Mystery oil pressure problem

Hi Darrell
Normal temps run anywhere from around 180 when the load is light and it is
cool out running around at low speed to a little below 220 on the Humvee.
When you are running 210 or above you will see the oil pressure drop as it
thins out. Chevron Delo 400 is good fleet grade oil. I do not see the oil
breakdown as much running Mobil 1 synthetic. You can swap the temp sender
that controls the fan clutch valve to get the fan to come on at 195-200 and
I think the engine is happier and less stressed, but what you have now is
normal.

Also be aware that when you are running hard up a mountain at altitude with
a non computerized mechanical DB2 inj pump you will be running very rich if
you are hammer down. The last time I went over Wolf Creek Pass in CO in the
Humvee I was pushing it and I remember the black smoke reminded me of the
old semi trucks you used to see all the time years ago. Anyway your entire
exhaust system will be carboning up and wet-stacking due to all the
incomplete combustion. Anywhere you have a tiny leak you will have an oily
mess of oil combined with carbon dripping. Exhaust manifold to head seals
are slightly leaky at times and you will see the result dripping down. Not
to worry.

Glenn
93 4dr M1043

-----Original Message-----
From: Darrell Ramsell [mailto:daram@comcast.net]
Sent: Monday, October 17, 2005 1:37 PM
To: Military Vehicles Mailing List; G Shaw
Subject: Re: [MV] Mystery oil pressure problem

I think you hit the nail on the head Glenn.

I was driving about 60 and I was towing my M-101 trailer with a few hundred
pounds. I have gone over the Sierras a few times before but never with the
trailer. My temperature was bouncing between 200 and 217. When it reaches
217 the fan kick in and drops to 200 but with in 5 minutes or so the fan is
kicking in again.

Thinking of temperatures, what is the normal operating temperature for a
HMMWV? In my vehicle if I drive flat and level at 55 it stays around
200~210. If I drive faster or go over hills it rises to 217 and the fan
kicks in but I've never seen it go over 220. I know the danger limit is
230.

One other thing, the oil I was using was 15-40 Delco 400.

Anyway, the next time I tow the M-101 over the mountain do you recommend an
precautions that I should take.

Thanks a lot Glenn, I feel better.

Darrell

----- Original Message -----
From: "G Shaw" <K9ESU@aim.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Monday, October 17, 2005 12:03 AM
Subject: Re: [MV] Mystery oil pressure problem

Hi Darrell
That would be perfectly expected since the engine had been working under
heavy load for a while and your temp was probably above 190 or so also. The
oil was just breaking down under the load and heat. Your readings were
still well within spec. 60 is actually on the high side for a Detroit 6.2
anyway with a warmed up engine. You can expect the conditions you saw when
towing a heavy trailer or climbing mountain grades, or running at approx 60
in a Humvee for a while on the highway.

Glenn 93 humvee

-----Original Message-----
From: Military Vehicles Mailing List [mailto:mil-veh@mil-veh.org] On Behalf
Of Darrell Ramsell
Sent: Monday, October 17, 2005 12:47 AM
To: Military Vehicles Mailing List
Subject: [MV] Mystery oil pressure problem

Mystery

Gents

I drove my HMMWV this last weekend from the San Francisco Bay Area to Reno
and back. On my trip I experience an unusual oil pressure problem that I
hope some of you Diesel Engine Experts can help me with.

Friday night I drove out to Reno. As I was crossing the Sierra Mountains at

about 4,500 altitude my oil pressure dropped about 15 psi. Normally when I
drive it's at 60 psi & 30 psi when idle. So now it was at 45 psi. I
stopped at a Rest Area and check for leaks and the oil and everything was
fine. I also tested the engine. When I stepped on the gas the oil pressure

went up then dropped when I let of the gas. I asked a trucker at the stop
for some advice. After he check things out he said I should be okay. As I
continued the oil pressure reading dropped to 30 psi but the engine seemed
to be running fine. By this time I had reached the summit and since the rest

was down hill I decided to continue on. As I started going down hill the
oil pressure went up to about 40 psi and stayed there. I finally made it to

my destination with no problems.

I discussed the problem with some friends in Reno and they felt I should be
able to drive home. So I drove back to the Bay Area today and my oil
pressure was normal all the way home (60 psi driving & 30 psi idle). In
fact it ran just fine.

The only other thing I noticed was that there appeared to be some oil
residue around where the exhaust manifold attached to the block but it was
just in one spot and I could tell it this was fresh or not.

So my thoughts now is that perhaps I might had a fluke with the oil pressure

sender unit or gage is going bad. But the oil residue around one of the
exhaust manifold and engine block concerns me. Maybe the gasket has a small

leak or it's something else and if it does I don't know if it's related. So
if anyone can help me solve my dilemma I'd appreciate it.

Thanks

Darrell

----- Original Message -----
From: "jhooah" <jhooah@mindspring.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Sunday, October 16, 2005 12:14 PM
Subject: [MV] TP filter, 'secret" Fuel ingredients and AN/TAS-4 parts

>
> How about using the Toilet paper filters for filtering the WVO as a
> pre-filter, then burn it in the Deuce... Should save $$$ on the
> primary filters.
>
> The "Secret" ingredient that company sells is likely the pre-mixed Lye
> and methanol so you can merely add it to a vat and do the rest of the
> work like Bjorn has done in individual steps.
>
>
> Funny thing happened following the Mil Show the other day, the local
> FBI called up to ask if I knew anything about a guy driving an
> Anti-Tank missile jeep around my area during a rain storm last
> Saturday... I said "Sure, it was me"...... Seems someone called in to
> complain about my demilled TOW jeep driving to the show... Really
> something a terrorist would drive around in when they are trying to
> sneak up on you eh?
>
> I'm seeking AN/TAS-4 Thermal Night sight guts... I want to fix the
> Thermal for the kids to see through....(don't want any other TOW
> electronics, not going for operational system here, just the thermal
> parts...) Could buy a Soviet version,maybe Iraqi, but that's not
> "restoring it" and defeats my intended purpose. if you haven't looked
> through a Thermal, do so at a Military show one day...Neat, just like
> "Cops" chasing crooks with

> helicopter stuff.
>
> Regards
> W Winget
> Virginia
> www.vmpa.us/aw
>
> XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
>
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