A restricted air inlet can cause an increase in vacuum in the intake tube (which draws on the crankcase via the CCV system).

 

Yea, I didn't check the air filter. I'll need to look at it, and the air intake tube.

 

Looks clean..
Yes on the filter, kinda leading to any doc/service info offered up. And, if an intake restriction exists on a higher RPM test, generally positive vacuum at the fill would be substantially increased.
And restricted air,,, meaning if the air box actually seals up.. The stock box was common to break the locating eyes or at the buckle tabs.. Something else to check...

 

You mentioned the engine bay for clean.
Is the under side on back as clean?
Normal topside cleaning is pretty standard, into the wheel wells, axles etc or any walk around visual points,, but usually the chassis/center gets none or just a light dusting and at times is an indication as to general use condition. But again, it looks to be in better than average condition..

 

Funny you mention that, the last truck I looked at had broken clamps/tabs on the air filter box and the air filter was absolutely filthy. I passed. This one looked good on the box but I didn't open it to check the air filter.

Under the truck looked decent. NO RUST at all in cab corners or rockers. Just a very small amount on drivers door at the bottom on the inside, very small though.

I think I'm good with this truck. I'd just never seen a 7.3 diesel not have at least a little smoke come up during the blowby test. The fact there was slight suction at the oil fill tube made me think something could be wrong with CCV.

THANK YOU for your help. It has put my mind at ease.

I will post pics and an update if they don't sell it before Thursday morning. The dealership is also throwing in some brand new nerf bars and replacing the window visors if the deal goes through.

I still need to look at the one about an hour away.











I haven't seen this one yet but it isn't as nice cosmetically. Haven't ruled it out yet, it is about 2k less on cost. We will see.

I will update.

Thanks again.

 

You bet.

The air box is fairly easy to repair.
The red is pretty stunning . My .02

 

Update. They sold Red before I could get her. I was in the dealership Sat and they sold it Monday morning. So I continued my search and found this one from a private seller. 1999 ext cab F350 DRW 4X4 7.3 powerstroke.

More miles and not as pretty as red, but saved almost $4500 and she started with 9 degree weather today here in Missouri. Ran strong with a relatively new jasper tranny and no blowby. Underneath looked good with relatively Very little rust and no leaks.

Only need to lose the KN air filter and do the oil change. Plan on buying arch oil fuel and oil additive with Rotella 15w40 oil.

Here's some pics of the new addition:





Thanks again guys for the help. This is my first diesel so I'm sure I'll have more questions down the road.

 

Congrats on the new rig!

 

Hi all. New to the site, excited to see so much info.

I have searched the threads and haven't come up with much, but here is the issue that's buggin me: Late 99 F250 4x4 Crew 7.3 PS (273K) I will be driving for 20 minutes to 4 hours and the speedometer will just drop out along with cruise control, overdrive indicator flashes on shift stick. At this time i'm keeping speed by RPMs. Pull in for fuel, or rest or food. jump in start the truck and speedo is back for a while. Considered temp issues, then did 4 hour trip in heavy snow, same issues.
Love the truck, Love the power but this issue is concerning. Oh and yes it is chipped but I leave in stock setting. None of the other electrical stuff is affected.

Anyone have same issues?

 

Are the shifts normal when the speedo drops out? Or are they extended out, forced, harsh etc?
Id be suspect of the speed sensor, PCM needs the signal to manage shifting as well as a speedo input.