5.0 smoke test results

[JoshT]

Purchased a smoke tester last week to help track down any post swap vacuum leaks prior to tuning. Well there were definitely a few locations where smoke was escaping. Some that shouldn't be, and some that I'm not sure about.

Just a reminder Incase I forgot to put it in my sign or something. This is a V8 swapped 1999 Ranger with a 2000 explorer 5.0L as the donor. Just finished a rebuild on the engine.

Already made a post about the intake duct being cracked and trying to locate a replacement or repair. Also had smoke coming from the following:

• EGR Valve

Leaking out of the holes circled below. I've read conflicting opinions as to whether it should or should not leak during a smoke test. Next test I'll pull the vac line and see if anything escapes from the vacuum port, if so bad diaphragm.

• IAC Valve

Leaking from the vent cap circled. Seems that this is normal, nothing to be concerned about.

• Throttle shaft on throttle body

No picture but a decent leak around the shaft behind the spring. The throttle body was ported with the intake. If they did that it can be disassembled, I guess I need to pull it apart and see if there are any seals in there that could have been damaged. If nothing there, the intake was ported out to 75mm, so maybe see about adapting a 70-75mm unit from eBay? Don't want to spend 2-300 on a BBK or Accufab to modify, but eBay has import units for less than $100.

• #3 spark plug

Looks like an o-ring got damaged when installing. Those will get changed out for bigger soon enough.

• Oil cap

Probably not a major concern, but I'll see about getting a new one. If smoke can get out, unmetered air can get in.

• Dipstick tube

With smoke going into the crank case, of course it's going into the dipstick tube as well, but the stick is in and it's not leaking out there. Turns out that there are a few small pinholes where the bracket was welded to the tube. Very minor, but I might see about applying some high temp silicone or some JB weld and blocking them.

That's all so far. Will see if there are more after getting those fixed.

 

[Rick]

A smoke tester is on my list. Do you like the one you purchased? Have a link?

 

[410Fortune]

Very nice to see the results! I bet most 5.0
Have similar leaks
The iac and oil cap seem Like Normal leaks as long as they are not huge I see them as par for the course

We did have a Jasper 306 with a
Misfire code smoke machine revealed a gross
Leak at the egr valve…that fixed it I’m wondering if it was in the same Spot as your egr leak.
The egr valve has a diaphram
Below those holes in the side, one would think the diaphram should be air tight? Need to test a new one

 

[vroomzoomboom]

a friend of mine actually make his own smoker.
he used a metal paint can, a bbq regulator so it would be regulated to something like 4-6 lbs of psi, clear tube, some wiring from a space heater, and attached them to two bolts so you can hook it to your battery. you drop some baby oil in the can, hook the wire up to a battery. when it heats up, it burns the oil, the can is pressurized with are and forces the smoke out the clear tube.

pretty similar to this.

 

[JoshT]

A smoke tester is on my list. Do you like the one you purchased? Have a link?

Don't know if this will work.

ITEFDTUTNE Automotive Smoke Machine Built-in Air Pump and Pressure Gauge, Evap Smoke Machine Leak Tester,19-23 PSI Dual Mode Auto Fuel Pipe System Leak Detector for EVAP, Vacuum, Fuel and Leak Testing https://www.amazon.com/dp/B0D1C6DDQB?tag=seriouexplor-20

I was looking at the Solary brand because good reviews, and I've heard from people with personal experience. I liked the SD302 model for features and included accessories. Knowing that 90% of these machines come off the same assembly line, I shopped around and found the cheapest with same options and accessories. I think it saved be about $20 at the time, now the prices are practically the same.

Works well IMO, but have nothing to compare to. DIY is definitely an option, but by the time I bought all the bits and pieces I needed or wanted, it made more sense for me to buy.

 

[410Fortune]

Good advice. Smoke machine a must for finding hard to spot leaks on these efi rigs

I don’t have one yet, I need to get one
My resourceful customers have saved a couple of projects for me that were getting difficult to diagnose by using smoke
(Issues afte the trucks were home we found using borrowed or Built smoke Machines)

 

[donalds]

I have the Solary smoke machine
I use baby oil in it and it works great

 

[JoshT]

Updates...

I posted about the intake duct in the other thread. The short version is that I patched it was Shoe Goo, it's holding, and I should have a replacement enroute.

EGR valve: Hope this picture shows up and demonstrates well enough where it is leaking from. That is the only place that the EGR appears to be leaking. Nothing escapes through the vacuum port with it unplugged, but some of the smoke you're may be coming from the unplugged vacuum hose. That's not to say that when I eventually attempt the exhaust side that there won't be more, but intake side first.

IACV: It's just a whiff from the cap, or the crimp for the motor. Not really even enough to get an image of it or tell exactly where its coming from other than the IAC. I'll probably replace it anyway. I hate seeing this crusty IACV, but the new one I bought during the rebuild didn't work right. I need to see if it had a warranty and get an exchange if not too late.

Throttle Shaft: Repaired. Disassembled throttle body and found that the shaft is sealed with o-rings. Installed new o-rings, reassembled, no more leaks. Mostlikely cause is that when the porter did the throttle body is disturbing old o-rings or they didn't debur/chamfer the edges of the shaft bore holes and it damaged the o-ring on reinstall. Some times an old o-ring will seal until its disturbed then it's over and they removed the shaft to port, but didn't replace them. When I was reinstalling the shaft after installing new rings, I cut two on the sharp edges of the hole before I got smart and hit them with a debur/chamfer bit.

I'm still exploring the possibility of replacing the TB with a larger aftermarket unit.

Oil cap: Didn't leak in the latest test, maybe wiping the seal off and reinstalling was all it needed. Even so, I've got a new Motorcraft cap ordered and it'll be here this weekend. Like the IACV, as fresh as the rest of the motor is, the faded cap kind of looks out of place.

Spark Plug & Disptick Tube: Leaks weren't noted this time, but I also didn't run the test as long.

PCV Hose: This is a new one. PCV hose was leaking where it enters the back side of the intake. Honestly the hoses did not appear to be in bad condition when I reinstalled them. I'm wondering if it's just not seated good, but don't have good access to try reseating it either. It kind of looks like there might be interference between it and the fuel feed hose that could be putting the vacuum tube at an odd angle for seating on the nipple. I'll take another look at it (tomorrow?) and maybe install a hose clamp. Push come to shove, when I remove the upper intake to install new injectors, I'll rebuild that whole PCV manifold.

Is there a good reason for the PCV lines to split and draw vacuum from two locations on the intake? Seems like just going straight from PCV to intake, no tee, would be sinpler and less prone to leaks.

 

[410Fortune]

Ford had two or theee different pcv hose routings on these intakes it just depends on which intake you have. There are at least 3 different lower intake and upper intake setups on the 96-01 5.0 most of the changes happening 96-98

The pcv is usually connected to two of the larger ports on the back and hooked to them with a plastic tee. When that tee brakes I have used brass fittings there many times but I have also set them up so the pcv is only
Connected to one port. The hoses are all 3/8 so I am not sure using two ports has any advantage (more
Flow)

The pcv grommets on these like to dry up (thanks ethenol) and then the pcv is loose fit. Ford added the foam to help keep it seated? Just a guess. Regardless I use a supple
Grommet when I can and I like to glue the grommet to the intake with some rtv and make sure the pcv is seated in there firmly

You don’t want any leaks at those ports that is for sure

 

[JoshT]

The pcv grommets on these like to dry up (thanks ethenol) and then the pcv is loose fit.

Brand new grommet was installed, and it's not leaking at the valve end of the hose. I'll keep the glue in mind if I have a problem with it int he future.

Mine uses a kind of "J" shaped hose assembly with one connecting at the rear and the other hooking around and going into the front of the intake. Tee is fine, just leaking where the rear hose is going into the intake. I think it's hitting the fuel supply line and holding it at a bit of an angle. If I can get my hand in there I think I can reroute the hose and get it sealed up.

I'm still kind of up in the air about the EGR valve, but I think I have a plan of action now. Still don't have a clear answer on whether the EGR should leak like it does, and there isn't a new one available locally to try and see. Even if it is, I now suspect that I have another issue there. When I had the vacuum pine pulled off the top and running smoke test, smoke was coming out of the vacuum line. Well the vacuum solenoid that controls the EGR valve wasn't receiving power and should have been closed, no smoke should have been coming out of the hose.

I was originally going to do a V8 swap on an older 80s truck and deleting EGR was part of the plan. I have the block off plate for the EGR valve, I already have a spare EGR gasket, and I have a plug that fits the EGR port in the header. As long as the ports are sealed, lack of an EGR valve may cause a CEL, but it shouldn't cause any problems with any running. So, I'm going to temp delete the EGR for testing purposes. If it runs better with the parts gone I know I've either got a bad EGR, a bad vacuuum control valve, or both. Then I'll fix as approprate.

 

[JoshT]

Well, that seems to have helped. I may have a constant CEL now (EGR codes), but the truck seems to be running much smoother. Granted I only drove it for about a half hour, but the idle has cleaned up quite a bit and it's not stumbling or stalling when I come to a stop like it was. Time and miles will tell.

If this continues I'll place an order for a new EGR valve and solenoid.