Finally, Some Good News

Wanted to share my story here in case it can help someone else who experiences this same problem...

I've pretty much been at my wits end with this truck since I bought it back in April. From the moment I got it home I've been dealing with a phantom PS leak and a large or small puff of smoke when I start it up. I figured I'd have to learn to deal with the smoke as long as I'm not burning too much oil and just pray for the best with the engine seals, but the PS leak was driving me crazy.

I put the truck up on jack stands, had my wife turn the wheel while I'm laying under the car - nothing. Take it to the mechanic, and he did the same thing with his buddy and can't find anything either. He tightens up the clamps hoping he can fix it. Still slowly leaking. I call another mechanic - he tells me it's gotta be something simple - replace the reservoir because maybe it's letting air in. Did that, still leaking. Finally I give up and take it to the stealership. I figure maybe their fancy diagnostic tools can figure out my problem. They look at it for an hour and tell me it's probably leaking at the reservoir, that will be $1300 to replace all the lines. Yeah no thanks, back to square one.

I go to pick up the truck - it smokes on start up, but worse than normal this time. I get out on the road and it's still coming out. I look out my mirror as I'm pressing on the gas - sure enough smoke is coming out as I accelerate. WTF? It's so bad I can't even see behind me. I pull over and get a tow back to the dealership because 1) I don't want to ruin the truck any more and 2) It's a serious hazard to me and everyone else the amount of smoke blowing out my exhaust. Could this get any worse?

I finally get a call this morning - they have great news for me. The power steering air control valve failed. My power steering fluid was getting sucked into the engine air intake this whole time! Not only was it taking all of my PS fluid without any sign or warning of what was going on, it was also what was causing my truck to smoke!

The moral of this story is: if you have a phantom PS leak AND your truck is smoking on start up - check this valve!

Very happy I'm going to be able to enjoy this truck for the first time in a long time.

 

Thanks for posting! I didn't know our trucks had such a thing.

 

Excellent..!

 

Glad you got it figured out.

 

Here's a replacement of it. I wonder if this is what other ppl have complained about with puff of smoke on startup.

https://www.youtube.com/watch?v=hMu5HiQ15pg

 

Definitely could be. The one thing I noticed was that the amount of smoke I got was *not* a function of how long the truck sat like I assume it would be with bad valve seals. I could drive mine, let it sit for 20 minutes, and then start it back up and get a big puff of smoke. This had me starting to think it was a bad fuel injector, but I'm stoked it was my power steering problem the whole time.

 

Bad/leaky fuel injector is what I'd seen as the cause of some other folks' issues. Also head gasket. Even some claims that a leaky fuel injector hydrolocked the motor with fuel after the truck sat for XYZ period of time.

Stoked to see it be something so simple. But that little bastard is expensive for new OEM!

 

Neither was their time spent diagnosing it, but at this point it's a small price to pay for the stone that's gonna kill both birds.

 

I had this happen to me. Exact symptoms. PS fluid tank would run dry in 2-3 days without any signs of leakage. White smoke at startup. Chased the problem for a whole month. Was cleaning out the throttle sensor when the air intake had lots of PS fluid stuck into it. Thought it was odd but didnt think to much of it. Did a gas check to see if the Head gasket was blown... Finally stumbled upon a thread saying PS air control valve gone bad can cause this. Swapped the valve and quickly fixed the issue.

 

Very interesting. I'll have to put this in the memory bank.

 

Is this just a 4.7 issue or can this happen with 2.5 gen 5.7 as well?

 

Yeah really. If it’s an easy swap, I may just do it as maintenance, I’m at 285k, might not be a bad thing to replace

 

Having no knowledge of the 5.7L, and only just begun my understanding of the 4.7L. I would say this is a 4.7L issue only unless your 5.7L uses the same power steering pump.

 

Nah. Any vehicle with a vacuum actuated valve on the high pressure p/s line can have this happen.

 

Then pay me no mind.

 

The key to diagnosing issues with smoke involved and isolating their cause(s) is the color of the smoke. Oil-related will always have a bluish tint to it, whereas fuel-related will be more white.

 

And power steering fluid is ???

I kid, but ... sometimes it's not always easy to tell the difference in smoke coloring. Takes quite a bit of smoke!

 

Looking at replacing this valve here soon, do you have to drain the PW reservoir?

 

Trace the two lines attached to it and you'll have the answer to your question.

You should find there's no line going back to liquid side the power steering system. Only air/vacuum. The video a few replies up shows you the location.

Here is the test process to verify whether or not the valve is bad, before you blow all that cash on a replacement valve - legit OEM units were really damn expensive last time I checked, and I probably wouldn't want to go non-OEM on that part.

And don't buy one on scAmazon or fleaBay, 50/50 chance (or worse) you'll end up with a very very-legit looking counterfeit part.

 

thanks for the response! Yup the valves are still pretty pricey. I got lucky and snagged a few at my local junkyard, however each time I took one off there was a ton of PW fluid that drained out as well. That’s why I was wondering if I should drain the reservoir or if the fluid that came out was what was left in the pump. The previous owner deleted the valve (stuck a bolt in the opening) so I can’t test it without installing a new one.

 

good to know about this potential issue

 

I'm bumping this post because 1 great information and 2 you just helped me find out wtf was wrong with my truck.
I was about to do a leakdown test even though my coolant and oil looked fine it was smoking so bad, like 007 smokescreen bad. Thanks again.

 

Spendy ass part though, eh?

 

Yeah found OEM Toyota for 80 shipped. I'm just capping everything off till that part comes in, the PS is way overboosted anyway.