My 2006 F-350 is my baby and she acting like she has a cold :-(. When I start it in the am, the truck seems to bounce a bit between 700-750 rpm erratically. It will idle perfect then do a little bouncing then go back to a normal idle. After the truck is warm, I don't notice the issue. Not sure why is happening. I have also noticed when I let the truck idle for 5 min. or so, the turbo will ramp up and down. Is that normal? (FYI, I live in Texas. It's not too cold here.)

Lastly, I was speaking to my mechanic about replacing the head studs among other things. I have no problems yet and my truck has almost 140K on it. I am trying to be proactive. He mentioned a recent study he found out claims if I replace my studs one by one without replacing the gasket (if it is not bad), I will be able to push up to 75-100 psi. If I replace the head gasket with the studs, I can only push about 45 psi. I will most likely never push this much psi, but it is interesting.

He says the reason for this is because of the bond the original gasket has made over time. What are your thoughts on this? Oh yea... its about half the cost and he has already started doing it with other customers.

Thanks in advance!

 

Answers/questions are above in red

 

And whats His Cost to do studs???

I don't by his gasket theory we are dealing with High cylinder pressures when things get rocking and rolling

 

@ Money_Pit. The reason I know the turbo is ramping up and down is because I hear it from the exhaust. It is a whistle noise, so I'm pretty sure its the turbo. It does not speed up by much, but I do hear it. It will speed up for about 10 sec. then go back to normal for a bit and then do it again.

I mean "Boost when I say PSI"

Do you all think they lift the cab if only replacing the studs one by one? If not, I could do it myself.

Thanks.

 

@ Blade35. His cost was a bit under 6K. This was to replace gasket, new studs, EGR delete and new tuner.

All the above but replacing studs one by one without new gasket, about 3K.

I have already done the "Semi-Bullet Proof Kit" by Bullet Proof. I was just thinking of deleting it while in there. Not sure. I hear so many people say to just get rid of it. I went with Bullet Proof at the time because I was worried about EPA.

Thanks.

 

The turbo will only "ramp up or down" when your engine speed changes. The problem is fluctuating idle, not turbo.

If you push 75-100 PSI boost, ( 25 is normal on a stock 2006 engine) you'll probably see your heads flying through the hood of your truck and landing on the pavement behind you. I'm calling BS on the mechanic.

One stud at a time does not require lifting the cab, and engine stays in place.

 

the turbo will fluctuate between 15% and 85% depending on your flash.
if you have something to monitor with (SG2 ,dash boss, torq ) you can see the VGT move

 

$3k just for studs? That's a little steep, considering the studs cost about $430.

 

This is very funny, thanks for making me laugh today

 

I suspect there is some level of inaccuracy in how the OP repeated what he thinks the mechanic said.. and we are all just further morphing the "story" each time..

I would suggest the OP go back to the mechanic and get specifics on what is being proposed - because if you aren't EXACTLY sure on what you are getting you frequently get what you deserve

 

Yea, I thought so to, but I couldn't figure out what the mechanic said concerning this job where 75-100 vs. 45 of anything would apply to the job.

I agree, get clarification from the shop.

 

if you have a 140k on your head gaskets, I would not try this if you had less may be worth a shot.

 

There are a few reasons to do head studs. One is the head gasket is blown due to a failed EGR cooler (usually due to a clogged oil cooler). The second is you plan to run fairly extreme tunes to get significant boost in horsepower. If the head gasket isn't blown, the EGR cooler is in good shape, your oil cooler is not clogged, and you don't plan to add 100 hp, then you should not do head studs. The stock studs are 100% reliable in a healthy, stock tuned engine. Particularly a 2006 with the latest flash - it has a monitor for the oil cooler clogging and the turbo sticking and will light the wrench light so you know you have a problem. The 2006 will also cycle the turbo open and closed at idle. It does this to prevent the turbo vanes sticking with long idle periods causing soot in the exhaust.

Your cold idle problem sounds like stiction, but it could also be a failing FICM. Get a Scangauge or other OBDII monitor and see what the FICM voltages are, and monitor your coolant and oil temperatures. Also think about batteries if they are old, and put a voltmeter on the alternator with the engine at 2000 rpm fully warmed up - should be 14 volts or so. If you aren't familiar with stiction, it is the oil shuttle valve on top of the injector sticking. The shuttle valve is opened and closed by the FICM, and lets the 550 - 3200 psi high pressure oil in to fire the injector. The tiny shuttle valve gets varnished with oil byproducts and starts to stick so the control over the injector firing gets rough. It usually goes away when the engine warms up. The fix is new injectors or some say you can rebuild and polish the shuttle valve. Some have had success with some pretty expensive oil additives.

Brian

 

I wouldn't say the stock bolts are 100% reliable. I have replaced plenty of head gaskets in stock trucks. The replacement bolts with the correct torque have proven to be very reliable.