Ford v10 consuming Mobil 1 5w20 Recomendations of weight? Would 5w-30 be better?

Quantico

Thread starter
Joined
Oct 10, 2021
Messages
441
Location
Wisconsin
I'm sorry to hear of your injury. Makes it hard to do any mechanical diagnosis, much less work.

In all honesty, if this were mine, I might not even fix it. I ran an old Toyota 4 Runner for over 100,000 miles with a rear main seal leak.

It leaked out about a quart every 1,500 miles, or it burned and leaked it, I was never certain.
I just purchased a 2007 sequoia as i like it better and I dont know how long I want to run my ford truck.
At 700 / 800 miles per quart of oil used and driving 3000 miles a year. Adding 4 quarts a year or so is no big deal.

I crawled under my truck with powerful lights and could not see any oil leakage from valve cover or front or rear seals. Its a 5 speed manual trans. So its harder to hide a leak on the transmission side.

I was a professional mechanic for years. I can find an oil leak. And a quart every 700 or 800 miles leaves a drip.
Not seeing it in my exhaust. No smell of oil either.
 
Joined
Oct 26, 2008
Messages
1,272
Location
Northern, NY
A few months ago my ford f350 used 3 of 6 quarts. In 3000 miles ...but over a year...

Started over with new 5 w 20 mobil 1 and consumed 3/4 qt in 550 miles.. so i want to try a heavier thicker oil.

So. 5 w 30 would protect more but 5 weight is 5 weight.

So maybe 10 w 30 mobil 1 ??

Or I have lots of 15 w 50 mobil 1 I could mix with 10 w 30 maybe ?? Maybe 2 or 3 quarts of the 15 w 50 ??
What is your opinion ?

I had a similar situation with the V10 in my F350. It had thousands of idle hours on it and had not been very well maintained by the previous owners. The oil consumption was noticeably less with 5w40 HDEO, so that is what I ran in it. I live about an hour South of Montreal and used the truck for plowing snow for 10 years, so it got plenty of subzero starts. it was still running good when I sold it last year.
 
Joined
Aug 23, 2010
Messages
3,704
Location
pa
oils with a smaller first # use that as base oil + viscosity improvers get it to the second # in the spec, so your 5-40 is a 5 at 40C + a 40 at 100C. todays cheeper fake synthetics are a good value + may flow better than a comparable conventional. in winter a 10-40 may work + slightly warmer may tolerate a 15-40. not suggest redline $$$ but their real synthetic diesel 15-40 cold spec 40C is same as their 10-40 + going lower than the 40C spec conventionals thicken faster than synthetics. i would prolly try 15-40 rotella synthetic if starting is an issue dump it + replace with a 10w or 5w 40 fake synthetic
 
Joined
Jan 16, 2017
Messages
1,328
Location
Palmer, Alaska, USA
Heavy-Duty Engine Oil. Akin to the Shell T6 5W-40 Heavy-Duty (Diesel) Engine Oil mentioned a few threads back. That would be a great place to start. Otherwise, my recommendation is Costco's Kirkland 15W-40 HDEO. It's inexpensive, starts well in cold weather for a 15W-40 (15 is the "Winter" viscosity rating), and is SN-rated for your gas engine. Either will serve you well.

BTW, I just left Milwaukee last summer, and am back in the Anchorage, Alaska area. Worked for MPD for 4 years, was the Communications Systems Mgr. :)
 
Joined
Jan 2, 2004
Messages
9,579
Location
California
I think U-Haul wanted their customers to top these off with 15W-40 if the oil was low - and that’s also the oil they use in their locations with shops. A majority of the U-Haul fleet was the older Ford mod motors, the 5.4/6.8 but the 6.2/7.3 has made inroads.

A mod motor using oil is nothing new, I’ve read the valve seals are a culprit but it’s also an engine with long timing chains that tends to shear oil.
 
Joined
Dec 26, 2005
Messages
22,279
Location
Upper Midwest
oils with a smaller first # use that as base oil + viscosity improvers get it to the second # in the spec, so your 5-40 is a 5 at 40C + a 40 at 100C. todays cheeper fake synthetics are a good value
So this magical oil you’re describing thickens as the temperature increases?
 

OVERKILL

$100 Site Donor 2021
Joined
Apr 28, 2008
Messages
52,219
Location
Ontario, Canada
oils with a smaller first # use that as base oil + viscosity improvers get it to the second # in the spec, so your 5-40 is a 5 at 40C + a 40 at 100C. todays cheeper fake synthetics are a good value + may flow better than a comparable conventional. in winter a 10-40 may work + slightly warmer may tolerate a 15-40. not suggest redline $$$ but their real synthetic diesel 15-40 cold spec 40C is same as their 10-40 + going lower than the 40C spec conventionals thicken faster than synthetics. i would prolly try 15-40 rotella synthetic if starting is an issue dump it + replace with a 10w or 5w 40 fake synthetic
That is possibly the worst take I've read on viscosity and the Winter rating on this board in my entire time being here.
 

Quantico

Thread starter
Joined
Oct 10, 2021
Messages
441
Location
Wisconsin
To OP: Have you checked your right side head gasket. The 2v modulars leak oil externally from the right rear of the right head gasket.


My 01 is 6 quarts.
I just took 45 min and both head gaskets and valve cover gaskets are oil free. I laid under the truck with a bright light and found no oil leaks
 

Quantico

Thread starter
Joined
Oct 10, 2021
Messages
441
Location
Wisconsin
A week ago i took the truck to a shop. They found zero oil leaks or pcv problems. I also did the complete look over as did another mechanic friend. No leaks.
 
Joined
Dec 4, 2013
Messages
584
Location
Maryland
HPL aka High Performance Lubricants has an Oil Additive that might help, its worth a shot since it sounds like there are no leaks.
 
Joined
Dec 31, 2017
Messages
11,473
Location
SE British Columbia, Canada
One of the places I used to work at had a shop truck F450 with flatbed, and same V10 engine. Shop owner got tired of adding oil every week, so he finally had mechanic replace the valve cover gasket, despite not seeing any leaks. Replaced, and turns out it was leaking oil from the very back of the valve covers, onto the bell housing, and rest of transmission and driveline. It was hard to notice as engine looked dry otherwise.
Saw something similar in a You Tube video. Two mechanics were planning on changing the rear oil seal on a Chevy LS engine. They had dropped the transfer case and transmission. The rear of the engine block was covered in oil leaking from the oil pressure sensor. You should have seen the look in their faces.
 
Top