Truck Shopping

[DocBar]

Hey guys, I'm in the middle of truck shopping and came across a 99(late) w/166,000 miles on it. When I started it up, lots of white smoke came out of the tail pipe and when I did the oil cap trick, it was chugged straight off the oil fill neck. Any ideas on what could be the problem? I'm not going to buy the truck, but I'd like to help the kid out that owns it. Unfortunately, my AE is set up for Windows 7 and I'm on Windows 10 and my connector is in Houston. Can't scan it.

 

[ghohouston]

You're saying blowby chugged out of the oil fill? If so, that would explain the smoke as well. Pop the intake tube off and see the sandblasted compressor wheel for evidence.

 

[DocBar]

You're saying blowby chugged out of the oil fill? If so, that would explain the smoke as well. Pop the intake tube off and see the sandblasted compressor wheel for evidence.

Blowby literally blew the cap off of the oil fill neck. So you think the air filter dusted the engine? It has the OEM airbox on it. No mods that I could tell. It looked bone stock. I didn't bother driving it due to the blowby test and serious amounts of white smoke coming out of the exhaust.

 

[uncool]

Rings would be my first bet.

I did not take pictures, but the 246,000 mile truck I bought had a stock air box and the intake was caked up/dusted pretty bad. When I swap turbos, I will get a few pics of the wheel. What gets me, is that this motor, with as bad as the intake/wheel is/was, still made 395psi compression on all cylinders. Will even make 22 psi of boost with no chip.

 

[DocBar]

Rings would be my first bet.

I did not take pictures, but the 246,000 mile truck I bought had a stock air box and the intake was caked up/dusted pretty bad. When I swap turbos, I will get a few pics of the wheel. What gets me, is that this motor, with as bad as the intake/wheel is/was, still made 395psi compression on all cylinders. Will even make 22 psi of boost with no chip.

Rings or burnt valves was my 1st guess. No history on the truck but the couple of years the young man that has the truck tells me.

 

[ghohouston]

Well, either a neglegent owner never changed the air filter, the clips were left off/filter lid not installed properly, the intake tube was cracked and not noticed, or clamp was left loose. I have trouble believing a 7.3 at that mileage would already have blowby like that, unless something I stated above happened, but anything is possible...

 

[DocBar]

Well, either a neglegent owner never changed the air filter, the clips were left off/filter lid not installed properly, the intake tube was cracked and not noticed, or clamp was left loose. I have trouble believing a 7.3 at that mileage would already have blowby like that, unless something I stated above happened, but anything is possible...

There's always not changing the oil and having a chip/programmer on it with no gauges. Canned tunes and a kid driving have torched many a vehicle.

 

[DocBar]

Could it possibly be injector/HPOP related?

 

[ghohouston]

Could it possibly be injector/HPOP related?

Not unless an injector hung open or had a bad spray pattern, i.e. cylinder washing. Bottom line, it likely does have some cylinder wall, piston ring wear/broken ring (s), or even a cracked piston. Valve issue is possible as well. My money would honestly be on the motor has been dusted though. Seen it all too many times working in fleet trucks. We spent over $1,000,000 per year with ford at my previous employer, with a fleet of over 400 strokes. You can have SOME blowby and still have decent compression numbers, but it it shot the cap out like you said, that motor needs to be compression tested. There is a way you can tell if cause is rings or valves. Compression test first normally, record your numbers. Take whatever cylinders had low numbers, go back and put a few decent drops of oil in the gp hole (obviously not enough to hydrolock), and test again. If your numbers go up, it's rings.

 

[DocBar]

Not unless an injector hung open or had a bad spray pattern, i.e. cylinder washing. Bottom line, it likely does have some cylinder wall, piston ring wear/broken ring (s), or even a cracked piston. Valve issue is possible as well. My money would honestly be on the motor has been dusted though. Seen it all too many times working in fleet trucks. We spent over $1,000,000 per year with ford at my previous employer, with a fleet of over 400 strokes. You can have SOME blowby and still have decent compression numbers, but it it shot the cap out like you said, that motor needs to be compression tested. There is a way you can tell if cause is rings or valves. Compression test first normally, record your numbers. Take whatever cylinders had low numbers, go back and put a few decent drops of oil in the gp hole (obviously not enough to hydrolock), and test again. If your numbers go up, it's rings.

Thanks for the info. I'll pass it on. BTW, I'm looking at an '01 ECSB 4X4 w/ only 125K on it. Truck looks very clean in the ad.

 

[Arisley]

Blowby must come through/around pistons. No way for valves to add blowby.

 

[Vader's Fury]

:whs:

I agree on the dusted motor. We have had a few here on the farm due to the dusty roads. Now all the trucks are running 6637 filters.

 

[ghohouston]

Blowby must come through/around pistons. No way for valves to add blowby.

If there's a cracked or broken valve, it will allow the compression to leak, but yes, you're right, they cannot add to blowby. I was referring more to compression checking.

 

[Arisley]

Exactly. Massive blowby (strong enough to blow the cap off when placed on the fill tube) makes a compression test a waste of time. Motor has to come out.